Advanced materials and additive manufacturing processes provide the foundation for cleaner and more efficient power generation solutions. Photo courtesy: Energy Florida/CAPE

Gas turbines have become an increasingly important part of the U.S. power generation mix, especially as regulatory and market trends have made gas turbines much more competitive in terms of price and emissions signature, relative to alternatives such as coal power generation. Gas turbines are poised to become the most important thermal energy and propulsion device in the global economy within the next few years.

The U.S. Energy Information Administration (EIA) projects that almost 60 percent of new power generation capacity within the next 20 years will be provided by natural gas-fired, combined cycle power plants. Together with the rise in renewable power generation, especially wind power generation, this shift has profound implications for the trajectory of the global power generation sector in coming decades. The shift is already having a significant impact on power markets within the United States and Europe, where renewable and gas power generation are underpricing and therefore squeezing out coal-fired generation, as well as reducing the profitability of baseload power sources such as nuclear facilities. Gas-fired power generation surpassed coal as a source of electricity in the United States for the first time ever in the spring of 2015, and given current trends, natural gas does not seem likely to relinquish its leadership position as a source of power generation in North America at any point in the near future.

The large increase in gas production from the shale gas boom in North America has substantially reduced prices for natural gas since 2008, and significantly altered the economics and price structure of the gas power generation landscape. In many (though not all) international markets, the global glut in oil and gas supplies has similarly reduced natural gas spot prices and improved the economics of natural gas-fired facilities. Contributing to their attractiveness, gas-fired power generation facilities often have a smaller footprint and many balance-of-plant components are available “off the shelf”, allowing for rapid permitting and set up of new facilities, and reducing the cost of construction. In a world where emission signatures are becoming increasingly important and regulated, gas turbine power generation facilities emit relatively low levels of pollution: no sulfur dioxide, low levels of nitrogen oxides and particulates, and less than half the carbon dioxide of comparable coal-fired facilities.

All of these factors contribute to a significant rise in the attractiveness of gas turbines for power generation systems. Furthermore, gas turbines provide significant short-term ramping and responsive power production capability, allowing them to provide backup capacity for variable renewable power resources such as wind and solar installations. As more renewable generation capacity comes online, this ability to provide responsive, cost-effective power is driving significant growth in new gas-fired power generation installations.

As gas turbines become ever more prevalent in the power generation community and adapted for a range of applications including industrial energy efficiency through combined heat and power installations, their operational parameters and efficiency ratings are in need of consistent improvement. Current gas-fired power generation facilities are approximately 42 to 44 percent efficient in simple cycle (one gas-fired turbine, hooked to a generator) and approximately 60 to 61 percent efficient in combined-cycle operation (including an attached heat recovery steam generation loop, steam turbine and generator(s) to harness waste heat for additional power generation).

There are a broad range of new technologies in advanced manufacturing that are being applied within the gas turbine design, engineering, manufacturing, and repair communities.

These new technologies allow for enhanced performance and shorter time to market for new improvements and upgrades.

In order to improve the efficiency and performance of today’s turbine designs, manufacturers are looking to improve aerodynamics, produce higher pressure ratios, and enable higher turbine inlet temperatures in the next generation of machines. A number of different advanced manufacturing techniques can help achieve these goals, including new materials, more precise or complex geometries, enhanced cooling architectures, and new types of high-performance coatings.

A number of companies and research teams are demonstrating printing entire engine components, such as this fuel injector, as one integrated piece. Photo Courtesy: NASA

A key enabler for increased efficiency and reduced emissions in industrial gas turbines is the development of high temperature materials applicable to the harsh and high vibration environment in these machines, and associated manufacturing techniques suitable for prototyping, production, and repair.

Although these have each been a primary focus of technology development within the industry for decades, new techniques and applications are emerging to address the challenges of high temperature materials and related designs.

Additive Manufacturing

One of the most exciting areas of new technology in gas turbine engineering is in additive manufacturing or 3D printing. This technology has been in commercial use for nearly three decades, although it is only recently being applied to metals at commercial scale. Additive manufacturing allows a machine operator to take digitized engineering designs and transform them into fully functional objects. The material is added in layers and bonded by heat deposition or chemical processes; then more layers are added to produce the desired three-dimensional shape.

Additive manufacturing technology opens up an entirely new design philosophy for turbine parts and components. This process can reduce component complexity by reducing the number of steps necessary to produce a part or component, or by consolidating several components into a single integrated piece. Additive manufacturing of metallic parts for the turbine industry is an active area of research for many manufacturers and university research institutes around the world.

The process of adapting additive manufacturing techniques to the turbine environment is still a work in progress. As just one example, the underlying characteristics and properties of many metal powders (especially high-temperature super-alloys) are not yet well-understood and tested to the industry’s exacting standards. In addition, the replicability of the build characteristics produced by different additive manufacturing machines, even of the same model and manufacturer, remains a challenge. Many industry participants have found that in practice, the output of each individual additive manufacturing machine must be assessed and certified separately, and all production information and parameters must be tracked meticulously as part of the quality assurance process.

Given the challenges in adapting this technology to scale up for manufacturing, one area of particular interest in the short term is additive manufacturing for castings. Many industry participants are looking at new ways to utilize this technology to accelerate the design and iteration process by providing rapid tooling and other capabilities (such as replacing the lost wax process in complex castings with 3D printed cores). This can save months or years and millions of dollars of engineering time within a development program, whereby new iterations of parts can be produced and tested within days rather than months.

Several companies are already implementing additive manufacturing in the production of small components and the repair and refurbishment of legacy parts. The 3D printing environment allows for companies to produce parts for repair or refurbishment on demand rather than having to stock large numbers of legacy parts for their customers. This reduces costs and improves response time for customers, and provides a great opportunity for improved efficiency within the repair and refurbishment business. For example, a pump manufacturer reduced impeller replacement costs by up to 90 percent and cut lead times for new part(s) by over a month using 3D printing. According to 3D print supplier ExOne, the finished part took two weeks and cost less than $1,500 using 3D printing methods, while a traditional pattern-based replacement would have taken 6 to 12 weeks and cost between $5,000 and $15,000 by comparison.

Several companies are looking at ways to repair blade tips, burner tips, and other small repairs which might have traditionally necessitated the disposal of a part that now can be safely and effectively refurbished and reused. For example, Siemens Power & Gas is actively utilizing 3D printing technology to repair burner tips, allowing it to recycle and reuse components that normally would have been disposed of, and saving its customers time and money.

A number of companies and research teams are pursuing 3D printing of full blade assemblies for testing as well as airfoils, fuel injectors, and a variety of other components. Safran Microturbo, an engineering firm based in Toulouse, France, recently demonstrated the ability to 3D print an entire gas turbine assembly (albeit on a small scale). Many of these applications are being implemented first in the aviation engine industry, as the weight savings and value-add in that sector is more significant than in the industrial gas turbine market, but many of these innovations will soon also be integrated into the industrial gas turbine fleets of major manufacturers.

Ceramic Matrix Composites

Another advanced material with great promise for gas turbine performance improvements is Ceramic Matrix Composites (CMC), which promise highly superior thermal resistance at approximately one-third the weight of current nickel-based super-alloys. CMC are a composite of intertwined ceramic silicon carbide fibers embedded in and reinforcing a continuous silicon carbide-carbon ceramic matrix. This material has been in development for nearly 30 years, and is being implemented in aviation engines in the shroud for first stage turbine inlets in GE’s LEAP engines. CMC are also being assessed by a number of other manufacturers for applications within the industrial gas turbine environment. For small turbines, the use of CMC could result in turbine blade designs without the requirements for advanced cooling and thus improved efficiency through reduction of bleed-air. However, for large turbines, concerns regarding elevated mechanical stresses and fracture properties of the CMC are still prohibiting their practical implementation in turbine blades. Non-rotating components such as combustor liners, stators, and shrouds will see increasing implementation of CMC, and as their mechanical properties are better understood and design parameters improved, CMC may be targeted for implementation in other parts of the engine as well.

A considerable amount of work is also being done in new coatings and coating application technologies. Significant new advances in coatings have not occurred for nearly 40 years. Most major coating compounds were originally identified in the 1950s and 1960s, and a great deal of fundamental research is being conducted in order to identify and improve upon the existing coating formulations and deposition techniques, allowing for higher firing temperatures and greater operational efficiency of next-generation gas turbines. Substantial effort is also being made on methods to embed instrumentation and sensors directly into turbine components utilizing additive manufacturing or other techniques. Enabling reliable sensors within machines will allow for much more direct measurement of operating parameters and anomalies, resulting in much greater precision in maintenance intervals, reduced downtime, and substantial improvements in operational performance.

The “Rising Tide” of Technology

Although many of these improvements are driven by the large gas turbine original equipment manufacturers (OEM), it is clear that the application of these new advances in production technology should not be restricted only to the largest and/or most sophisticated classes of engines. There are substantial opportunities for improvements in maintenance, repair, and overhaul of existing generation fleets, including legacy gas-fired, aero-derivative, and peaking power facilities. These new technologies will allow more rapid, efficient, and customizable retrofits and upgrades for existing power generation facilities, as well as improvements for new generations of power generation equipment.

A group of turbine OEMs, design firms, major research institutions and other public and private stakeholders are currently involved in an effort supported through the National Institute of Science and Technology’s Advanced Manufacturing (AMTech) program to support the assessment of advanced materials and manufacturing processes on behalf of the next generation of gas turbines and rotating machinery equipment. Coordinated by Energy Florida and the Gas Turbine Association, the stakeholders in the Consortium for Advanced Production and Engineering of Gas Turbines and Rotating Machinery (CAPE) have been evaluating a variety of techniques and technologies necessary to underpin the next generation of highly efficient natural gas-fired, combined-cycle turbines and generator sets. The partners have been reviewing the state of knowledge in a variety of related areas, and have developed a set of recommendations associated with further development of related technologies. These priorities are being coordinated with national funders, research institutions, and key stakeholders across the industry. An update on the AMTech CAPE effort will be presented during the PowerGen International conference and trade show in December 2016.

Diversity of Applications and Solutions

Although the centralized power production model remains strong in certain regulated markets and in many emerging markets that are still working to deliver fundamental capacity improvements to their grid, the power production landscape is more diverse. The power sector takes decades to fully integrate new technology due to the high complexity, long production lead times, high capital investment, and operational lifetimes of plants and equipment. Due to this fact, the gas turbine design and engineering community must actively cultivate an understanding of the needs of its customer base, both today and in years to come. The industry must adapt its design and engineering solutions to be flexible enough to meet its customers’ future requirements, considering the trends and development of the quickly changing renewable energy markets. The decades-long development cycle for gas turbine technology requires some educated guesswork regarding the fundamental technologies that will underpin future technology cycles. Customers will always need power, but as we have seen, the ways they receive and use that power can change.

The gas turbine industry should consider ways to “hedge its bets” by investing in a range of materials and technical solutions that support improvements in smaller, less expensive machines, in addition to supporting large-scale material science efforts to improve performance and longevity of increasingly sizable and complex combined-cycle power systems. The power generation community should work to ensure that all voices are being heard, and that we are actively sharing information and driving improvements across the range and breadth of power generation equipment and applications. Today’s world demands nothing less.

Author

Michael Aller is executive director of Energy Florida and the Consortium for Advanced Production and Engineering of Gas Turbines and Rotating Machinery (CAPE), based in Cape Canaveral, Florida. Timothy Franta is project manager of the CAPE. Helge von Helldorff is a project associate with the CAPE, and a doctoral candidate in aerospace engineering at the Florida Institute of Technology in Melbourne, Florida.

A joint proposal was filed in California that lays a roadmap for increasing energy efficiency, renewables and storage while phasing out production at the Diablo Canyon power plant by 2025.

Pacific Gas & Electric, along with labor and environmental groups, filed with the California Public Utilities Commission (CPUC) a joint proposal to increase investment in energy efficiency, renewables and energy storage beyond current state mandates. The plan also includes steps to phase out PG&E’s production at Diablo Canyon, which would be shut down when the operating licenses expires on Nov. 2, 2024 for Unit 1, and Aug. 26, 2025 for Unit 2. PG&E ended any efforts to renew the operating licenses, and asked the NRC to suspend consideration of the pending renewal application. PG&E will withdraw the application upon CPUC approval of the joint proposal.

Natural Gas Generation Rises to New High in July

Power produced with natural gas reached an all-time high in July, the U.S. Energy Information Administration said last month.

In its short-term energy outlook, the agency found that gas-fired power plants generated 4,950 gigawatt-hours of power each day in July, up 9 percent from the previous record high set in July 2015. The increase was driven by warmer weather, which boosted the use electricity for cooling, and low gas prices.

Natural gas will overtake coal as the leading source of power generation this year, accounting for 34.3 percent of all generation, according to EIA’s report. Coal’s share of the generation pie will be 30.3 percent in 2016. Nuclear and renewable resources will account for 19.4 percent and 14.8 percent of generation, respectively, this year.

First Offshore Wind Farm a Sign of Things to Come

The nation’s first offshore wind farm is set to open off the coast of Rhode Island this fall, ushering in a new era in the U.S. for the industry.

Developers, federal regulators and industry experts say the opening will move the U.S. industry from a theory to reality, paving the way for the construction of many more wind farms that will eventually provide power for many Americans.

Deepwater Wind is building a five-turbine wind farm off Block Island, Rhode Island to power about 17,000 homes. The project costs about $300 million, according to the company.

CEO Jeffrey Grybowski said the Block Island wind farm enables larger projects because it proves that wind farms can be built along the nation’s coast.

“I look at Block Island as sort of the key to unlocking the code of how to do offshore wind in the U.S.,” he said.

This comes as other states have “suddenly woken up” to offshore wind’s potential, Grybowski added.

EDF Orders 80 Vestas Wind Turbines

Vestas Wind Systems A/S Vestas Wind Systems A/S will supply 160-MW of wind turbines for future U.S. projects built by EDF Renewable Energy.

The master supply agreement includes supply and commissioning of the 80, 2.0-MW wind turbines as well as an Active Output Management 5000 service agreement and a full-scope service package. Nacelles, blades and towers will be produced at Vestas’ Colorado facilities. The contract covers deliveries in 2016 to 2019.

Exelon to Buy FitzPatrick Nuclear Plant

The FitzPatrick nuclear power plant in upstate New York will avoid closure as Exelon Generation said it will assume ownership of the plant from Entergy.

As part of the $110 million agreement, Entergy will transfer FitzPatrick’s operating license to Exelon.

The New York Power Authority agreed to transfer the decommissioning trust fund and liability for the plant to Entergy. Once regulatory approvals are obtained and the deal is finalized, Entergy will then transfer the fund and associated liability to Exelon.

The transaction is expected to close in the second quarter of 2017 pending approvals from state and federal agencies, including the U.S. Department of Justice, the Nuclear Regulatory Commission, the Federal Energy Regulatory Commission and the New York State Public Service Commission.

The deal was announced after New York regulators approved the Clean Energy Standard, which provides several incentives for the state’s nuclear power plants.

LG&E, KU to Cap Remaining Coal Ash Ponds

Louisville Gas and Electric (LG&E) and Kentucky Utilities (KU) received approval from the Kentucky Public Service Commission to cap and close the remaining coal ash ponds at the utility’s active and retired power plants.

The plan is part of an effort to meet federal environmental regulations.

While the commission did not approve the entire unanimous settlement agreement reached in June between all parties, the ruling does allow the utilities to invest nearly $1 billion to meet environmental regulations, including the EPA’s Coal Combustion Residuals rule that became effective late last year.

KU and LG&E filed projects, with an estimated cost of $678 million and $316 million respectively, mainly for the capping and closure of the utilities’ surface impoundments.

Amazon Data Centers Powered by New Wind Farm

Pattern Energy Group dedicated a 150-MW wind power project in Indiana that would help supply power to data centers run by Amazon Web Services.

The Amazon Wind Farm Fowler Ridge consists of 65 Siemens 2.3 MW wind turbines. The turbine blades, nacelles, towers, and transformers were manufactured in the U.S.

Mortenson Construction managed construction of the site. About 175 workers, on average, were on site during construction, and there are ten full-time permanent workers to operate and maintain the facility.

The wind farm is expected to add an estimated $45 million over 25 years to the regional economy through property taxes, landowner royalties, and support for local causes.

Kemper Power Plant to Cost $43 Million More

Mississippi Power said it will take at least another month to put into operation the coal gasification power plant it is building in Kemper County.

Atlanta-based Southern Company, the utility’s parent, said it is pushing back the completion date from Sept. 30 to Oct. 31.

Mississippi Power spokesman Jeff Shepard said the extension will increase the cost of the plant by $43 million. However, the company will absorb those costs, he said. Southern says it needs time to modify equipment and reach sustained operations. The increase pushes the total cost of the plant above $6.8 billion. The cost of the plant and associated coal mine were originally estimated at $2.9 billion.

Holt Named CEO of Siemens’ Power Generation Services

Siemens appointed Tim Oliver Holt as the new CEO of its Power Generation Services Division (PGSD).

Holt is currently the CEO of the Power Business Unit within the PGSD. He will replace outgoing CEO Randy Zwirn, who is retiring.

“With Randy’s retirement, we’re losing a highly experienced leader who has played a major role in shaping our Siemens service business and the digital trends of the future. He’s had a strong influence on the development of the power generation business at Siemens for nearly twenty years,” said Lisa Davis, member of the Managing Board of Siemens AG. “Tim Holt’s many years of experience make him the perfect successor.”

Duke Energy Completes Los Vientos Wind Power Projects

After more than four years, the last of the Los Vientos wind power projects in Texas has been completed by Duke Energy Renewables. Altogether, 426 wind turbines were installed over more than four years.

The final project, Los Vientos IV with a capacity of 200 MW, recently began commercial operation near the Rio Grande in Starr County, Texas. Los Vientos I was commissioned in 2012. The five projects have a total capacity of 900 MW.

The power and associated tax credits from Los Vientos IV are being sold to Austin Energy under a 25-year power purchase a greement.

NextEra to Buy Oncor for $18.4 Billion

NextEra Energy announced plans to buy an 80 percent stake in Texas transmission company Oncor Electric Delivery for $18.4 billion.

The deal is part of the restructuring of Energy Future Holdings, which declared Chapter 11 bankruptcy two years ago. If the deal is approved, NextEra would gain 200,000 miles of power lines and 8.6 million customer accounts. NextEra said it would maintain Oncor’s Dallas headquarters and would not lay off any employees or cut salaries for at least two years.

A federal bankruptcy judge must still approve the deal. The transaction is expected to close in the first quarter of 2017. The deal comes a month after NextEra terminated its $2.6 billion acquisition of Hawaiian Electric Company.

Renewable, Nuclear Power to Rise in North America

If the U.S. Clean Power Plan (CPP) survives in court, power produced with renewable and nuclear resources in North America will grow from 38 percent in 2015 to 45 percent in 2025, according to the Energy Information Administration.

The agency pointed to the recent agreement between Canada, Mexico and the U.S. to produce half of their power supplies from low-carbon resources by 2025.

The projection assumes implementation of the CPP, which was placed on hold by the U.S. Supreme Court, will begin in 2022.

“The extension of certain tax credits, significant cost reductions, and recognition of future CPP requirements result in a large increase in renewable generation between 2015 and 2025,” EIA said Tuesday.

During the same period, coal-fired generation will drop 13 percent while the share of power produced with natural gas rises 4 percent, EIA said.

Eos’ Znyth battery technology is designed for stationary, utility-scale storage. With a volume price of $160/kWh and a 15-yr life, the Eos Aurora® 1000│4000 DC battery system enables turnkey energy storage solutions with a levelized cost of storage of $0.07/kWh. The 4-hour battery is designed as a locational capacity product that reduces peak demand and debottlenecks congested nodes on the grid. Image Courtesy: Eos Energy Storage

Boothbay, Maine is the kind of town that still has general stores. And not any ordinary general stores-general stores with screen doors, and front porches, and rocking chairs. It’s the kind of place where old men drink Coke from glass bottles, where evergreen trees cling to craggy islands just offshore, where fishing trawlers are as common as automobiles. If you’re lucky and keep a close eye out, you might see a whale breach out past the breakers. And check out those wooden buoys hanging on the outside of that clapboard barn over there, or the lobster traps piled up against that dock house. If the wind blows in the right direction, you can even hear the clinking of the schooners hoisting their sails on the bay and smell the barnacles and other marine detritus collecting in the tidal pools. Can you hear the terns navigating the salt air?

Yes, Boothbay is a midsummer vacation heaven, so it’s no wonder that tourists flock to the area. The 2010 census puts Boothbay’s population at just 3,120 people, and that’s including the surrounding villages. But the area lies at ground zero of the vacation onslaught, so in the warm months those numbers soar. “Summer people”, they’re called, and if the four-season veterans like to complain about them, they become rather quiet when the dollar bills begin to change hands. Whether the tourists are walking the pre-colonial streets adrift in picaresque fantasy or lounging in Adirondacks on the waterfront like Kennedys, people love this town, and that love translates to real money.

But what most tourists don’t think about as they tuck into lobsters or peruse the shops for souvenirs for the grandkids is just how tricky their presence makes it to plan for electric service. Any time a population varies so dynamically from season to season, capacity planning at local utilities is bound to take on the aspect of a migraine. Just how do you ensure enough power in the summer without also having massive oversupply when the tourists are at the beach and not using hotel amenities, or when the winter surf turns gray and they go home altogether?

The short answer is, sometimes you don’t. Striking such a balance can indeed be a tricky business. In the past, utilities have struggled to walk this wire and have occasionally missed their marks, turning up with supply-demand incongruences.

“The electricity system is built for the peak minute, of the peak hour, of the peak day, of the peak week, month, year, and 10-year horizon,” says Johannes Rittershausen, CEO of Convergent Energy + Power. “Often another 15 percent is added on top of this for buffer.” He explains that planning like this ensures that utilities are prepared to meet customers’ electricity needs even at times of peak demand. But though this kind of capacity planning is standard and has worked out well traditionally, it results in a massively overbuilt infrastructure that goes underutilized in times of lower demand.

That’s why when greater capacity and reliability were required during the summer vacation season in coastal Maine, Central Maine Power (CMP) chose to explore Non-Transmission Alternatives (NTA) to shore up supply, rather than build an $18 million transmission line that would have otherwise been required. CMP called on Convergent Energy + Power, an energy storage asset developer that serves as a liaison between utilities and large users of electricity, original equipment manufacturers (OEM), and financing resources, to provide a solution that would “shave the peak”, allowing the utility to provide electrical power when and where it was required while better spending capital investment dollars in capacity infrastructure.

Convergent installed chemical batteries integrated by the OEM Lockheed Martin Energy Storage that allow the utility to generate power during times of low demand, and store it away to provide a multi-hour energy boost when demand once again peaks in the late afternoon. It’s like saving for a rainy day, only in this case the summer days in Maine are decidedly sunny and clear. Convergent retained ownership and operational responsibility of the energy storage project, and was able to provide CMP with a solution that addressed the utility’s infrastructure needs at less than 50 percent the cost of a traditional line upgrade. The Boothbay project went online April 1, 2015 and for two successful summers has helped support Maine tourists as they run their air conditioners and plasma screen televisions.

Like Your Computer’s UPS, Only Bigger…MUCH bigger!

Energy storage has been used on a small scale for years. The battery in the uninterruptable power supply (UPS) that you plug your computer into relies on technology not so dissimilar to larger energy storage applications, and big manufacturing and healthcare facilities have long relied on energy storage to support operations at the building or campus level.

While energy storage projects at utility scale are also not new, they do retain something of that new smell. In many cases, utilities lack the knowledge or experience to feel comfortable implementing such technologies on their own. “Utilities are interested in technologies like grid-scale energy storage,” says Rittershausen, “but they don’t always want to bear a long-term risk on new technology. Because of this, they often prefer to have a developer like Convergent step in and build a project, taking the construction and operational risk.”

Rittershausen explains that energy storage projects serve a variety of needs and, as such, take on different scopes. By and large, the energy storage industry breaks down into two categories: fast-response and long-duration applications. “There are technologies that are optimized for shorter charge/discharge cycles,” he says, “and technologies that are optimized for longer cycles.” Rittershausen cautions that talking about technologies without also discussing the problems they solve can be misleading. “It’s hard, for instance, to compare a flywheel and a six-hour battery,” he says. “No one would ever ask if they need to buy a racecar or a tractor. They’re both forms of transportation technologies, but they don’t equate in a side-by-side comparison of things like horsepower or zero-to-60 times.” The only relevant comparisons are made between technologies that solve similar problems under similar constraints.

Fast-Response Energy Storage

Some projects require fast-response energy storage, so they demand very fast charge/discharge horizons that occur several times a day, or even several times a minute.

Fast-response energy storage is mostly used for frequency regulation, voltage control, and power quality enhancement. In cases such as these, flywheels can be preferable to chemical batteries. Because flywheel systems are entirely mechanical, relying on heavy underground wheels that spin in vacuums to harness momentum for power generation, they do not suffer performance degradation at the end of their service lives. As long as flywheels are maintained and their worn components repaired, they are not vulnerable to the explicit lifespan limitations incumbent in battery chemistries, whose useful lifetimes are influenced by factors like charge rates, cycle numbers, and operating temperatures.

Convergent Energy + Power worked with Central Maine Power to install a 3-MWh battery asset engineered by Lockheed Martin. Shown here on the interior of the battery’s ISO shipping container, the energy storage installation was designed to reduce summer peak loading on existing transmission & distribution infrastructure cause by the tourist season in Boothbay, Maine. Image Courtesy: Convergent Energy + Power

However, flywheels are generally more expensive than chemical batteries and so make greater financial sense if the infrastructure is meant to serve needs that span decades. Owing to this, says Rittershausen, the vast percentage of fast-response energy storage solutions currently rely on lithium-ion battery technologies.

Long-Duration Energy Storage

Rather than regulate frequency and improve power quality as fast-response systems do, long-duration energy storage solutions are meant to shave the peak in times of high demand. They provide a power boost when a generation asset or transmission line would otherwise be overloaded in times of heavy use. They are generally called on for one to six hours of dispatchable power at a time, frequently on late summer afternoons when the weather is at its hottest.

Philippe Bouchard is Vice President of Business Development at Eos Energy Storage, which has worked closely with Convergent on past projects. Eos manufactures a proprietary battery technology called Znyth.

“Its’ an aqueous zinc battery that relies on a zinc hybrid cathode chemistry and is optimized for the stationary, utility-scale, grid-connected energy storage market,” says Bouchard. “So our product meets the needs of a very specific business case. We’re able to provide four to six hours of continuous discharge to reduce system peak demand.”

Eos’ Aurora 1000/4000 product is a 1-MW, 4-MWh DC system. It’s comprised of Znyth chemical batteries, which are sealed, static-cell sub-modules that are slightly larger than a shoe box. Each battery stores about 4 kWh of energy. Eos strings these together in series and in parallel, and packages them in an outdoor-rated module called an energy stack.

“Our manufacturing facility ships a roughly 42-kW, 167-kWh energy stack that’s 5-feet square and about 11 feet high,” says Bouchard. These energy stacks are delivered to the site via flatbed truck, where the EPC contractor can place it onto an integrated skid and simply plug it in. “It’s plug-and-play,” says Bouchard. “You don’t even need an electrician to install it.”

Six of these modular energy stacks can be aggregated into 250-kW, 1-MWh subsystems, which can themselves be aggregated into the full-sized 1-MW, 4-MWh product. This parallel aggregation creates in-built redundancies. “There’s no single common point of failure,” says Bouchard, “so issues can be isolated at the energy stack level.” Additionally, he explains, parts of the battery can be kept operational while other parts are isolated for maintenance.

The resulting product has a broad operating temperature range, and since it relies on a water-based chemistry, is not at risk of thermal propagation or runaway. Because of this, Bouchard says, the batteries do not require dedicated heating or cooling. They also don’t create any onsite emissions. Additionally, their small footprint ensures their ability to target capacity needs at the grid’s most congested nodes and load centers. They fit where they’re needed.

The Role of Energy Storage in the Larger Generation Ecosystem

While energy storage is often thought of as a way to smooth over intermittency issues inherent in renewable generation sources like wind and solar power, Rittershausen disagrees that this is the technology’s primary value in the current generation ecosystem. “So far, the intermittency issues associated with renewable energy resources have impacted the reliability of the grid almost not at all,” he says. “Once renewables reach a certain level of penetration, the grid may begin to lose stability and make energy storage solutions that much more important. So far though, that hasn’t happened in most places.”

Some studies suggest that a grid would need to reach 50-percent renewable penetration before reliability suffers in a way that energy storage could mitigate. Because of this, energy storage is currently more applicable for peak shaving than it is for combatting intermittencies in non-fossil generation. “Long-duration energy storage technologies are really designed to help utilities avoid the need to upgrade capacity to meet increased peak demand,” Rittershausen says.

Cost-effective batteries have begun to make capacity planning more flexible via the use of reliable, dispatchable, location-targeted battery solutions that avoid an overbuilt electrical system. Batteries make capacity additions possible on an incremental level. So if an existing facility is approaching a level of unreliable performance on particularly hot days, batteries can very quickly extend the life of that facility a little at a time, and in as little as six months from the contracting date, helping to ensure that loads don’t creep too high, and postponing the day on which more expensive capacity additions must be undertaken.

Rittershausen puts it like this: “Now that we have increasingly cost-effective energy storage solutions, it may not be good planning to build an entire electrical system for a resort town that is designed to support the few weekends in a summer when most tourists visit the area. Non-invasive batteries solve this problem much more efficiently and elegantly.”

The final project, Los Vientos IV with a capacity of 200 MW, recently began commercial operation near the Rio Grande in Starr County, Texas. Los Vientos I wascommissioned in 2012. Altogether, the five projects have a total capacity of 900 MW.

The power and associated tax credits from Los Vientos IV are being sold to Austin Energy under a 25-year power purchase agreement.

Vestas supplied 100 V110-2.0-MW turbines for the project and will service the project under a three-year operations and maintenance agreement, Duke Energy said.

“With the turbines installed at Los Vientos IV, Vestas crossed a historic milestone – 75 gigawatts installed in 75 countries,” said Chris Brown, president of Vestas’ sales and service division in the U.S. and Canada.

The facility was constructed by Wanzek Construction. Amshore US Wind provided development support for the project.

Duke Energy Renewables’ projects in Texas: 1,563 MW

• Sweetwater Windpower Project, Nolan County, 283 MW (of 585 MW total)
• Ocotillo Windpower Project, Howard County, 59 MW
• Notrees Windpower Project, Ector & Winkler Counties, 153 MW
• Blue Wing Solar Power Project, San Antonio,14 MW
• Notrees Battery Storage Project, Winkler County, 36 MW
• Los Vientos I Windpower Project, Willacy County, 200 MW
• Los Vientos II Windpower Project, Willacy County, 202 MW
• Los Vientos III Windpower Project, Starr County, 200 MW
• Mesquite Creek Windpower Project, Borden & Dawson Counties, 106 MW
• Los Vientos IV Windpower Project, Starr County, 200 MW
• Los Vientos V Windpower Project Starr County, 110 MW

CMR Group has launched a new series of electronic monitoring units for the nuclear power industry.

The S-Unit range has been specifically designed by CMR for the simple and effective condition monitoring of safety backup diesel genset systems used in nuclear power plants. Designed to be compliant with nuclear energy industry standards and ensure that backup diesel gensets continue to operate at optimum performance, the units provide advance warning of potential problems and serious damage, improving the scheduling of maintenance programs.

The next generation S128 and S129 units comprise easily configurable 32 channel analogue inputs for the accurate condition monitoring of key engine characteristics. These include measurement of exhaust gas temperature, bearings temperature, water temperature, stator winding temperature, pressure, lubrication oil temperature and other features.

Designed to withstand harsh and demanding operational environments, the robust units have two operational modes, providing a permanent display of the last channel manually scanned or the automatic display of all sensor channels.

A user friendly interface and front panel keyboard enables configuration changes to be made easily, allowing individual output relay settings to be modified and alarm groups and set points to be fixed.

CMR Group
Info http://powereng.hotims.com RS#: 100

Signal “Cross Talk” Solution

Alliance Sensors Group has solved the age old problem of cross talk between sensors even if the master signal conditioner fails.

When LVDT signal cables are bundled together or laid close to each other in a wire trough, even for short distances, the result can be a mutual interference phenomenon called heterodyning or “beating”. This effect is created when the frequencies of the oscillator in the individual signal conditioner driving the excitation signal to each LVDT vary slightly. Since the signal cables are close together, they can couple among each other, resulting in a very low frequency signal that is the difference between the frequencies of the individual oscillators. This difference frequency signal can ride on the DC output of the LVDT signal conditioners, appearing as low frequency ripple or noise with a period measured in fractions of a second, or as a repetitive slow drift with a period of many seconds. When a pair of LVDTs are used together for redundancy, this effect may be evident on only one channel of the system. In systems with larger numbers of LVDT channels, this effect may be found in one or more channels, depending on many factors like cable length and layout as well as shielding and grounding.

Alliance Sensors Group has considered this beat frequency problem with multiple LVDT installations and developed a successful solution to this problem. Because the S1A and its variants have a digital address for RS485 communication capability, we are able to use this digital feature to maintain the full redundancy of multiple LVDT systems. If the “master” were to fail, another “master” having a different digital address would instantly come on stream to maintain a single excitation frequency. In this approach the only thing lost in a “master” oscillator failure is the former master channel itself. For multiple channel LVDT systems, the integrity of the output signals from the other channels is fully maintained. This “auto-mastering” feature is unique to the Alliance Sensors S1A and its variants.

Alliance Sensors Group
Info http://powereng.hotims.com RS#: 102

Distributed Plant Monitoring

Siemens has extended its Sinema Remote Connect software for the efficient maintenance of distributed plants and machines to include a number of new security and virtualization functions. Alongside OpenVPN, Version 1.2 of the management platform now also features IPsec encryption, allowing a wide range of various machines with different security protocols to be flexibly connected. The new version is also capable of running in a virtualized environment. This not only increases the flexibility and availability of the platform but also the efficiency of maintenance and support services. The management platform is particularly suited for series and special-purpose machine building.

The Sinema Remote Connect management platform is a server application, allowing users to conveniently and securely maintain widely distributed plants or machines by means of remote access. Depending on the supported security protocols, machines can now be flexibly connected, either by OpenVPN or IPsec. This facility means that Sinema Remote Connect can communicate securely over routers with the majority of connected machines. Siemens also offers a complete solution for virtualization (Simatic Virtualization as a Service): The solution encompasses set-up of the Sinema Remote Connect Server, the configuration of virtual machines and their network structure, the installation and configuration of the operating system and ready-to-use installation of the Simatic software. To support the virtualized systems over their entire life cycle, Siemens offers a number of inter-coordinated services, including Simatic Remote Services for remote access by means of a cRSP (common Remote Service Platform), and Managed Support Services, which encompass all support activities surrounding the virtualized host system.

Siemens
Info http://powereng.hotims.com RS#: 103

Alarm Horns and Strobe Warning Lights

E2S Warning Signals launched the new ‘D1x’ range of alarm horns, PA loudspeakers and integrated alarm horn/Xenon strobe warning units employ the latest electronic technology and acoustic engineering in robust, marine grade, Lm⁶ aluminum enclosures. Designed to create the most effective warning signals available for use in Class I/II Division 1, Zone 1 & Zone 20 environments, the UL/cULs approved alarm horns and combined units are available with traditional directional flare horns or omni-directional radial horns that generate a uniform 360° sound dispersion.

The company also showcases its new ‘GNEx’ GRP Xenon strobe beacons, which add visual signaling to the explosion proof and corrosion resistant GNEx family. Suitable for all Zone 1, 2, 21 & 22 hazardous location applications the ‘GNEx’ beacons have extended temperature range with IECEx and ATEX approvals. For applications with high levels of ambient light the GNExB2 beacon is available in 10, 15 and 21 Joule variants producing up to 902cd – a very high output Xenon strobe. The GNExB1 offers a 5 Joule Xenon strobe in a compact lightweight enclosure. Complementing the family is the GNExJ2 Ex d junction box, which, having multiple cable entries and terminal configurations is suitable for a large variety of applications. All ‘GNEx’ beacons can be supplied as plate mounted assemblies configured with and without an alarm horn sounder or junction box. These new Xenon strobe beacon visual signals broaden the ‘GNEx’ family which includes alarm horn sounders, PA loudspeakers and manual call points for activation of fire alarms, gas detection and emergency shutdown systems.

E2S Warning Signals
Info http://powereng.hotims.com RS#: 104

Training Simulation Software

Siemens is launching Version 9 of Simit, marking a new generation of its acclaimed virtual commissioning and plant operator training simulation software. The new software generation is based on a standardized simulation platform. Using Simit 9, automation functions can be comprehensively tested for development or functional faults and optimized prior to actual plant commissioning using real time simulation and emulation. By adopting existing planning, engineering and automation data as well as libraries containing functionally capable components over interfaces to Comos and Simatic PCS 7, the new Simit generation helps real commissioning processes to be carried out more quickly, more economically and with fewer risks.

Simit 9 allows testing and optimization of the automation solution within the simulation and emulation environment on a completely virtual basis using a totally integrated virtual controller. The virtual plant test can be performed directly at the workplace without available plant equipment and without the need for in-depth simulation expertise.

The new Simit generation also offers scope for safe, efficient training of plant operating personnel. Different plant operating scenarios can be simulated using realistic training environments. Operators can be familiarized with the plant using original operator panel screens and automation programs in advance of actual commissioning. Using Simit as a training system not only reduces the use of actual resources, it also allows possible hazards for operating staff in running operation to be minimized or even avoided altogether.

Siemens
Info http://powereng.hotims.com RS#: 105

DC Power Converter

The Sinamics DCP DC power converter from Siemens extends the scalable power range achievable with a parallel connection up to 480 kilowatts. The high switching frequency enables smaller nuclear reactors to be used, giving the unit very space-saving dimensions. The integrated voltage control allows the DC/DC power converter also to be used as a high-power 0 to 800 V DC voltage source.

The Sinamics DCP is suitable for industrial and multi-generator applications in the renewable energy sector. As a buck-boost converter with scalable power, the device can work in either motor or generator mode. The unit can connect two DC voltage levels, irrespective of these levels, on both the input and output side. This makes the Sinamics DCP ideal for charging and discharging batteries and supercapacitors. Internal protective measures ensure that the connected devices are neither overcharged nor completely discharged. The high internal switching frequency makes the compact design and low weight possible. The overload capability of up to 150 percent of the rated current allows it to be used in even highly dynamic applications.

The Sinamics DCP DC/DC power converter can be used in a range of applications. These include its use as a hybrid system with energy storage in photovoltaic and wind power plants, or for covering peak loads in press applications. It can also be used in diesel-powered gantry cranes and storage and retrieval systems, as well as in rapid charging stations for electric cars, and as a voltage source for test rig equipment in the automotive industry. Stationary battery storage systems can also be implemented with Sinamics DCP.

Siemens
Info http://powereng.hotims.com RS#: 106

Solar PV String Inverter

Ideal Power Inc. introduced its new SunDial solar photovoltaic (PV) string inverter which includes an optional bi-directional 3rd port for direct integration of solar with energy storage during initial installation or any time in the future. The SunDial is a compact, efficient, and fully isolated PV string inverter with an integrated PV combiner, disconnects, and a built-in Maximum Power Point Tracker (MPPT). It also features an optional, low cost “plug and play” bi-directional DC port kit. This new “solar first, storage ready” design is the only commercial string inverter available with a field-upgradable, bi-directional energy storage port, making the system market ready today for the solar + storage market.

The initial SunDial product is a 30kW system (Model 30PV+S) based on Ideal Power’s patented and award winning Power Packet Switching Architecture with 1000V max PV DC input and 480V, 3-phase output. It is the first in a planned family of field-upgradable SunDial PV string inverters. An important new feature of the SunDial system will be a newly designed AC link providing true galvanic isolation from the AC to the DC ports, enabling PV installations to be either grounded or true floating. The new SunDial inverter is comparable in size and cost to today’s widely used transformerless PV string inverters, but is fully isolated and offers the additional value of an optional, upgradable fully isolated bi-directional port for direct storage integration. The SunDial can be applied to both new PV installations and PV system retrofits where there is a desire to add energy storage to an existing array.

Ideal Power Inc.
Info http://powereng.hotims.com RS#: 107

High Pressure Bellows Seal

Senior Operations LLC Metal Bellows has developed a high pressure bellows seal, the DELTA P, for use in injection valve applications. The DELTA P is capable of withstanding high external system pressures, while maintaining low differential pressure across the edge welded bellows. This low differential pressure feature enables the bellows to be designed with thinner material, which increases the stroking and cycle life capability. This bellows seal is ideal for use in gas lift valve applications. Senior has applied for a patent on this new technology.

The following are the main features and benefits of the DELTA P:

– Dome pressure: 1,000 to 15,000PSIG

– Injection pressure: 1,000 to 15,000PSIG

– 20,000 cycles minimum

– Inconel 718/625 bellows

– Incaloy 945/945X housing

Senior Operations LLC
Info http://powereng.hotims.com RS#: 1088

Updated Wireless Network Module

The WNM Wireless Network Module from Moore Industries has been redesigned with a new, sleeker housing and now incorporates both Serial and Ethernet communications in one model. The WNM, originally released in 2011, has been an accurate and reliable solution for sending process signals between remote field sites. The WNM provides a low-cost wireless communications link between field sites that are in rugged or impassable terrain, with a single unit transmitting for up to 30 miles and the ability to act as a repeater for a virtually unlimited transmission range.

The bi-directional WNM employs Spread Spectrum Frequency Hopping technology to avoid interference problems caused by crowded radio spectrums. This technology allows multiple radio networks to use the same band while in close proximity. Operating at standard operating frequencies of 902-928MHz or 2.4-2.4835GHz, the WNM does not require a regulatory license and can typically be installed without performing costly RF site surveys.

The WNM is ideal for use with the Moore Industries NCS NET Concentrator System®, as well as other SCADA and distributed I/O systems. As a result of its redesign, the WNM now supports data communications networks that use Ethernet and serial (RS-485) communications in one model. In each WNM network, one module is set as a Master. This can be set to communicate with a single WNM remote unit in a Point-to-Point architecture or multiple WNM remote units in a Point-to-Multipoint architecture.

Moore Industries
Info http://powereng.hotims.com RS#: 109

Energy Management Monitoring Systems

Carlo Gavazzi Inc. launched a new line of modular monitoring systems for energy management. VMU-C EM is a data logger system for small to medium projects, VMUC-Y EM is a hardware data aggregator for medium to larger projects and Em² Server is a software solution for large projects. They are designed to complement the extensive line of Carlo Gavazzi energy maters and current transformers.

The VMU-C EM is a combination of hardware modules, whose primary function is to collect data from a network of energy meters and environmental sensors and then make this data available to end users utilizing industry standard methods, such as integrated web server, FTP, HTTP and Modbus/TCP data transfers. In addition to data management, the VMU-C EM platform can provide a relay output, SMS or email alarms and scalable pulse rate inputs. The VMU-C EM can function as a standalone data logging solution for applications with up to 32 meters or as a data gateway for larger installations.

The VMU-Y EM is a data aggregator that is built upon the VMU-C EM hardware platform, with a primary function of aggregating data from a network of VMU-C EM data loggers in applications where support for more than 32 energy meters is required. The VMU-Y EM relies on VMU-C EM data loggers to collect the data from energy meters and environmental sensors, but it is also responsible for the management of collected data and web server function. Up to 10 VMU-C EM / 320 meters can be managed by single VMU-Y EM.

The Em² Server is a software solution provided as a Virtual Machine software appliance to be hosted either in a customer’s facility or remote server. Similar to the VMU-Y EM, the Em² Server relies on the VMU-C EM for communication with energy meters. It aggregates data in large applications with up to 100 VMU-C EM loggers / 3,200 energy meters and provides web server function.

Carlo Gavazzi
Info http://powereng.hotims.com RS#: 110

Shielding Products

WAGO offers a wide variety of shielding products to assist in eliminating unwanted electrical noise. Used with WAGO’s new shield clamp that features an exclusive latching spring, 790 Series adjustable busbars provide excellent shield contact and performance. The adjustable carriers are available with heights from 70 to 80 mm. Busbars can be cut to any desired length.

– Busbars are pre-connected to the DIN rail adapter – cutting installation time

– Adjustable T-connectors allow the busbar to be positioned horizontally and vertically

– Flexible mounting options with carrier on one or both sides and varying heights and orientations

Adjustable busbar carriers are also compatible with other WAGO shield accessories offering a one-stop solution that makes any installation quick and easy.

WAGO Corp.
Info http://powereng.hotims.com RS#: 111

Particle Measurement Lasers

Laser Components Flexpoint laser module series now includes dot and line lasers with 488 nm. Therefore, in addition to 405 nm and 450 nm, a third wavelength is available in the blue spectral range.

Depending on the beam profile, the output power amounts to up to 40 mW. Due to the narrow-banded emission of 488 nm ±2 nm, these laser modules are optimally suited for fluorescence applications, spectroscopic applications, and particle measurements.

In addition to standard modules, customized laser modules can be developed and produced at attractive prices.

Laser Components USA
Info http://powereng.hotims.com RS#: 112

High-Pressure Regulator

AURA Controls has introduced a self-relieving, high-pressure regulator designed to provide primary pressure control of non-corrosive gas or liquid for delivery pressures up to 4500 psig. The new EXH regulator is suited for applications including test benches, high-pressure cylinder control, hydraulics and more.

The EXH ensures accurate control and stable downstream pressure in a durable, compact design. Ideal for applications requiring variable delivery pressures, it vents excess downstream pressure to the atmosphere through the bonnet as the regulator set-point is reduced. Its high-load marginal spring provides consistent delivery pressures even at high-flow rates while its non-rising stem design minimizes the equipment’s footprint.

Fully configurable to meet end-user specifications, the EXH is available in PTFE, PCTFE, and PEEK seat materials along with orifice sizes up to 0.2 to accommodate application-specific process conditions. Standard threaded bonnets and screw holes allow the regulator to be flush or panel-mounted for ease of installation.

Combined with multiple porting configurations and an extensive range of delivery pressures, the EXH is the precise and reliable choice for high-pressure applications. Each regulator is 100 percent helium leak-checked and fully flow- and function-tested to ensure the highest levels of durability and performance available.

Aura Gas Controls
Info http://powereng.hotims.com RS#: 113

Field Force Automation Program

Doble Engineering Co., a subsidiary of ESCO Technologies Inc., released its Field Force Automation program, a customizable platform that helps power companies meet requirements of new NERC CIP regulations by standardizing diagnostic testing and data collection programs through a combination of rugged controllers, testing software, custom engineering and data management processes.

Using Field Force Automation, companies are able to consolidate field test data and automatically save and sync it from the jobsite to the office. By automating as many as seven manual steps in traditional testing workflows, companies can greatly reduce the risk of human error and expedite the data collection process. Supervisors and managers are able to immediately access the data the moment it is synced, review it in real time and remotely access the controllers to collaborate with their field engineers and verify test results before leaving the job site. Rather than having test data stored in disparate forms and various locations, Field Force Automation centralizes the data and drastically improves its security, ultimately providing the right people with access to reliable, comprehensive data.

One of the ways Doble’s Field Force Automation program helps companies meet the new NERC CIP Version 6 standards is through its rugged controllers which are configured as “locked-down” devices to ensure they are only able to execute necessary, work-related tasks and to limit its communication capabilities for security purposes.

The program also makes it easy for Doble to generate government-facing reports for clients to demonstrate compliance and adherence to testing and data management processes. These reports can show who has used the program, what system they accessed it from, its geographical location, the software version and the specific work that was done. Providing this level of specificity ultimately helps utility companies to successfully complete audits.

Doble Engineering Co.
Info http://powereng.hotims.com RS#: 114

Linear Position Sensors

H. G. Schaevitz LLC, Alliance Sensors Group is proud to release its LA-25-A series LVDT linear position sensors, designed to handle extreme industrial environments. Available in ranges from 3 inches (75 mm) to 15 inches (375 mm), the LA-25-A is ideal for roller gap positioning, process valve displacement, head box and actuator position feedback with the durability to withstand the harsh environments found in steam and hydro power plants; paper, steel, and aluminum mills; die and stamping presses; building and bridge monitoring; and industrial automation and fluid power systems. It can operate in hostile factory environments such as lubricant and chemical mists, airborne grit and dust, and typical industrial wash downs.

The robust LA-25-A LVDT linear sensor has a sturdy one-inch (25.4 mm) diameter heavy wall housing of aluminum or stainless steel, two double-contact shaft seals that keep fluids and solid contaminants out of its bore, and offers a choice of axial connectors or a cable in a metal cord grip.

The LA-25-A series permits a variety of mountings, including standard saddle-type clamps, a two-hole flange that screws onto its front bushing, and a single hole mount through a bulkhead up to 1/8 inch thick. The LA-25-A’s core is enclosed in a core extension rod assembly from which it can never break loose, while offering a sturdy male thread for easy mechanical connection. When mated with ASG’s SC-100 industrial LVDT DIN-rail-mountable signal conditioner, an LA-25-A LVDT becomes an ideal solution for heavy duty industrial applications for position sensing.

Alliance Sensors Group
Info http://powereng.hotims.com RS#: 115

Underground Cable Entry Seals

Roxtec UG solutions have been developed to meet the demanding requirements specifically in underground applications. Part of the Roxtec underground product family, the UG knock-out sleeve is designed to be cast directly into the foundation structure, and is easily attached to the casting mold prior to casting. A knock-out plate is located inside the sleeve to ensure a tight seal prior to routing cables.

The UG product can be installed below ground to seal cables entering through the foundation of electrical substations and shelters, as proven by UG test standards. These reliable underground solutions have been documented to provide optimal performance, especially when it comes to withstanding constant pressure.

Roxtec uses innovation to design the most reliable solutions that better meet the demands of challenging conditions in underground applications. UG seals are made of high-elastic EPDM rubber, developed specifically to resist a low constant water pressure.

The UG knock-out sleeve is designed to fit Roxtec UG seals and frames, and is available in three different standard industry sizes to provide customized protection for a variety of underground applications.

Roxtec
Info http://powereng.hotims.com RS#: 116

Continuous Gas Analyzer

Emerson released the Rosemount CT5100 continuous gas analyzer, a hybrid analyzer that combines Tunable Diode Laser (TDL) and Quantum Cascade Laser (QCL) measurement technologies for process gas analysis and emissions monitoring. The CT5100 can detect down to sub ppm level for a range of components, while simplifying operation and significantly reducing costs. Unlike traditional continuous gas analyzers, the CT5100 can measure up to 12 critical component gases and potential pollutants simultaneously within a single system – meeting local, state, national, and international regulatory requirements.

The CT5100 operates reliably with no consumables, no in-field enclosure, and a simplified sampling system that does not require any gas conditioning to remove moisture. The new gas analyzer is ideally suited for process gas analysis, continuous emissions monitoring, and ammonia slip applications.

The CT5100 is a unique combination of advanced technology, high reliability, and rugged design. Its “laser chirp” technique expands gas analysis in both the near- and mid-infrared range, enhancing process insight, improving overall gas analysis sensitivity and selectivity, removing cross interference, and reducing response time. The laser chirp technique produces sharp, well-defined peaks from high resolution spectroscopy that enable specificity of identified components with minimum interference and without filtration, reference cells, or chemometric manipulations.

Emerson
Info http://powereng.hotims.com RS#: 117

Thermal Inspection Camera

FLIR Systems, Inc. released the T1K series of premium HD thermal inspection cameras. Creating a new performance point at the top of FLIR’s uncooled thermal camera value ladder, the T1K series sets a new industry standard with an HD infrared detector delivering outstanding image clarity, exceptional measurement performance, and an intuitive yet simple hybrid-touch user interface. The new cameras allow users to find problem areas quickly, measure them precisely, and document and report findings for corrective action.

T1K series cameras feature a rich set of new hardware, software, and optical designs each tailored to take advantage of the new 1024 X 768 HD-IR detector. High fidelity images are created utilizing FLIR’s OSX Precision HDIR optics which feature a precision ultrasonic autofocus capability. The combination of the higher resolution detector and the variety of OSX lenses available allow users to view problems from longer distances and with greater accuracy, promoting better safety and more efficient workflow.

Advanced real-time image processing is done utilizing the integrated on-board FLIR Vision Processor, which combines FLIR’s patented MSX multi-spectral dynamic imaging with a series of other proprietary image enhancement algorithms to deliver highly detailed thermal and visual images to users while in the field. The advanced image processing features provide the highest quality images available in a compact uncooled system. Additionally, built-in audio and on-screen text/sketch annotation features support in-field documentation while the included FLIR Tools reporting software allows users to generate instant reports on a variety of mobile and desktop platforms.

The FLIR T1K series is available now through select channel partners and directly from FLIR.

FLIR Systems
Info http://powereng.hotims.com RS#: 118

EMAX4 Fans

Multi-Wing introduces the EMAX4 Fans, which provide up to 77 percent total efficiency.

EMAX4 has a computer-optimized blade design for maximum performance. Customized for your requirements, EMAX4 decreases noise by 2 to 3 dB and reduces energy consumption in air-cooled condensers, chillers, cooling towers, evaporators and more.

A modular design, EMAX4 is available with 5, 6, 7, 9 or 12 blades in diameters from 22 to 36 inches (559 to 914 mm). Pitch angles include 20 degrees to 48.5 degrees in 3.5-degree increments. EMAX4 blades are constructed of glass-reinforced polyamide (PAG), and the hub is made from pressure die cast silicon aluminum alloy.

Multi-Wing
Info http://powereng.hotims.com RS#: 119

Profibus-to-Fiber Converters

Moxa, Inc. is helping connect PROFIBUS devices with its ICF-1180I and ICF-1280I PROFIBUS-to-Fiber converters, which now feature Class 1 Div 2, IEC Ex, and ATEX certification for deployment in hazardous locations including upstream and downstream petrochemical processing, chemical plants, and other areas where explosive vapors are present.

PROFIBUS is the world’s most widely used fieldbus and especially common in the oil and gas industry. With the newly certified ICF-1180I and ICF-1280I, oil and gas users can now use optical fiber to connect their PROFIBUS devices and controllers in remote or hazardous locations. The industrial-hardened units offer 2 kV isolation protection for the PROFIBUS system and dual power inputs to ensure non-stop communications.

Rated for operation in environments ranging from -40 to 75°C, both units are capable of distances up to 4 km (2.5 miles) on multi-mode fiber, or up to 45 km (28 miles) on single-mode fiber in both ordinary and hazardous applications, a first for the industry. The ICF-1180I extends connections over a single optical fiber port, whereas the ICF-1280I extends connections over two optical fiber ports that can be arranged in a redundant ring for extremely high communications reliability.

In addition to hazardous area certification, the ICF-1180I and ICF-1280I offer protection from bus faults. The ICF-1180I and ICF-1280I work transparently to detect and recognize bus faults. If the bus fails on one side, the issue will not propagate through the ICF units and affect additional bus segments. In addition, the ICF units will also trigger an alarm notification to the field engineer on the location of the failure so that it can be quickly replaced with minimal downtime.

Moxa Inc.
Info http://powereng.hotims.com RS#: 120

Wireless Headsets

ComSTAR offers full duplex wireless that allow up to eight users to communicate simultaneously just like on a regular telephone. These revolutionary headsets are not voice activated and there is no delay when transmitting. They enhance industrial job site productivity and safety by providing instantaneous, “hands free” voice communications within an 800-yard range.

The XTreme is a specialty hard hat compatible ComSTAR headset that features miniaturized wireless circuitry and antenna installed right inside the ear cup. This streamlined “All in One” design is a breakthrough, eliminating the need for cables and belt pack transceivers.

ComSTAR operates within the DECT, 1920 – 1930 MHz band allocated by the FCC for voice communications only. No FCC licensing required.

ComSTAR
Info http://powereng.hotims.com RS#: 121

Emergency Lighting Inverter

Staco Energy Products released a new Three Phase, On-Line Double Conversion Emergency Lighting Inverter called the FirstLine P 924.

General Highlights on the FirstLine P 924:

– 58.5-225 Kw, Three Phase, On-Line Double Conversion, UL924 Central Lighting Inverter

– Features IGBT and digital signal processing (DSP)

– Emergency power provides FULL LIGHT OUTPUT from all lamps and fixtures for the entire runtime

Staco Energy Products
Info http://powereng.hotims.com RS#: 122

Expanded Linear Position Sensors Line

Alliance Sensors Group a div of H.G. Schaevitz LLC has expanded its sensor product offering by adding to its line the LR-27 and LRL-27 Series Inductive Linear Position Sensors. These are contactless devices designed for factory automation and a variety of heavy duty industrial or commercial applications such as solar cell positioners, wind turbine prop pitch and brakes, chute or gate positioners on off-road or agri-vehicles, robotic arm position feedback, and packaging equipment. With their compact yet robust design, superior performance, and excellent stroke-to-length ratio, LR-27 and LRL-27 sensors are ideal for both industrial and OEM position sensing applications.

Operating from a variety of DC voltages, the LR-27 and LRL-27 series offer a choice of four analog outputs, and all units include ASG’s proprietary SenSetâ„¢ field scalability feature.

The LR series also includes the LR-19 series for applications where a shorter length and smaller diameter body is required and the spring loaded LRS-18 for applications where the probe cannot be hard fixed to the measurand.

Alliance Sensors Group
Info http://powereng.hotims.com RS#: 123

For plants that need to move bottom ash, fly ash and gypsum to a landfill, the two-silo concept offers the flexibility to split the storage of the material to the plant and landfill and then move it rapidly to the landfill with no restriction on rate. Photo courtesy: BEUMER

As utilities consider ways to store and transport coal combustion residue (CCR) materials, a new approach to consider is the Two-Eurosilo concept, which can significantly reduce operating costs and simplify the movement of CCR to a landfill. The new EPA CCR rule focuses more on the integrity of impoundments, but how this material is moved and stored is important too. More operators are confronting the question of how to store and move their CCR waste because the volumes are enormous, and over time, small efficiencies add up to big savings.

The challenges of moving and storing CCR

No creative thinking has been applied to new CCR transport designs because moving this material is complicated. Handling three or four different types of CCR material requires complex storage and handling equipment designed to hold, and then transport, large amounts of each CCR constituent material. This drives the construction of more conservative and costly designs, while creating high capital costs to build and high operating costs to operate and maintain these systems. Also, CCR is not an ideal material to handle so engineers concentrate on traditional methods to do so. New concepts are considered speculative. The traditional way to store these materials includes, for example a concrete silo for fly ash, covered storage for FGD Gypsum, and a steel silo or concrete pad for bottom ash.

Innovative concepts for efficient CCR handling

When considering the large volumes of waste – the cost per ton to move this waste should be scrutinized. An innovative approach is to minimize the footprint and complexity at the power plant end and create surge storage at the landfill end, which provides flexibility in the plant operation. This is a departure from traditional methods because the CCR material does not lend itself to storage in a traditional mass flow silo. This concept offers flexibility for handling the CCR material which is critical. Being able to “push” the material quickly out to the landfill to a receiving vessel reduces pressure on the plant storage vessels. Having an efficient truck loading capability at the landfill contributes to the overall efficiency.

This concept uses a pipe conveyor to connect the power plant storage to the landfill storage.

The two Eurosilo approach

A Eurosilo, specifically designed to store highly cohesive material, is used at the plant to store the gypsum as well as the gypsum dewatering equipment. This creates a very small footprint.

A similar Eurosilo is also used at the landfill to store the comingled CCR waste. Trucks are loaded under this landfill silo with high loading efficiency. The pipe conveyor will carry the comingled CCR at a high tonnage rate from the plant to the landfill silo. This can be achieved at the maximum conveyor capacity.

A pipe conveyor is a great solution for transporting CCR to a dry landfill. The pipe conveyor can negotiate vertical and horizontal curves and it encloses the material in the direction of transport. On the return strand, the belt is closed with the dirty side facing in so no spillage occurs. This ensures compliance with EPA regulations.

Having a Eurosilo at the landfill allows the plant to quickly expel the daily CCR production to the landfill at a high rate per hour in a matter of a few hours. This relieves pressure on the plant operations and creates flexibility by allowing the plant operation to disengage from the landfill operation.

The plant portion of this concept envisions a feeder hopper to receive the bottom ash adjacent to the gypsum Eurosilo and then two fly ash silos to store the dry fly ash. The fly ash is conditioned under each fly ash silo while depositing it onto the pipe conveyor. All three pieces of equipment simultaneously reclaim their respective material directly onto the pipe conveyor.

Being able to reclaim in close proximity to the pipe conveyor and at a high rate allows the conveyor to operate at peak capacity saving significant power cost per ton because the large motors are operating at peak efficiency. The pipe conveyor can negotiate sharp curves and hills on the way to the landfill which eliminates transfers and additional conveyors.

Benefits of two-silo concept

The two silo concept impacts all aspects of the operation. Taking all subtle improvements into consideration helps illustrate how the landfill Eurosilo drives efficiencies.

Each constituent of the CCR waste stream has vastly different handling characteristics. The fly ash is dry and dusty and needs to be conditioned before transporting. Conditioning the fly ash is critical and has to be carefully done. The gypsum needs to be dewatered to between 10% and 15% moisture so that it is dry enough to transport but it can become sticky and can set up to some extent under pressure while being stored. Mixing these two constituents creates a better blended material for transport than either one on its own.

The benefits of this approach include capital cost savings; operating cost savings; easier operating methods; and environmental responsibility.

Capital cost savings can be achieved in the following ways:

• Consolidating the gypsum handling equipment footprint at the plant can result in an estimated savings of $8,000,000 to $10,000,000 depending on storage sizes needed.
• Much faster schedule to construct, the slip forming of all silos can be done one after another.
• A version of the concept uses no CCR silo at the landfill and in this case the capital savings are even higher (e.g., more like $15,000,000) but with this case the operating costs will be higher.

Operating cost savings can be achieved in the following ways:

• If the gypsum Eurosilo has the ability to consolidate the gypsum dewatering equipment on top of the Eurosilo at the plant, a substantial amount of equipment will be eliminated – such as the gypsum storage and dewatering buildings, transfer towers, additional conveyors, portal reclaimer, and even truck-loading bays,
• The gypsum dewatering and silo operation can be automated,
• Being able to move all CCR to the landfill at the maximum capacity of the pipe conveyor allows the conveyor to operate fewer hours per day and to operate at peak power efficiency while in operation. This saves the hours of operating the belt and allows the motors to run at the highest efficiency on their efficiency curves. This also pushes the belt replacement years further into the future and reduces idler replacements.
• The truck loading operation under the landfill silo is more efficient than traditional loading designs because two trucks can be loaded simultaneously with efficient queuing. The truck loading operation at the landfill can be done by the truck operators themselves if that is desired.

The two-silo approach allows for easier operating methods. Examples include:

• With this concept the bottom ash, gypsum and fly ash can be reclaimed simultaneously onto the pipe conveyor for transport to the landfill. As a result, there will be much less power required and fewer transfers required to get the material onto the pipe conveyor.
• Once at the landfill there would be a single conveyor discharge into the silo. Alternatively, the CCR can be conveyed to an emergency pile.
• Once the truck loading operation starts at the landfill the material will be loaded into trucks by a series of double augers that eliminates the need for any conventional conveyor transfers thus reducing the need for bin vibrators and air cannons that can be disturbing to local landowners.
• The material is transferred to the landfill silo in a matter of hours at close to the capacity of the pipe conveyor. This is more efficient because fewer people have to be involved or stand by waiting for the daily CCR production to transfer.
• It is easier to design redundancy into a silo than to other types of storage. For example, in the plant gypsum silo design from Eurosilo there is an emergency bypass of the silo in case the silo internals are being maintained and there is an optional truck loading spot under the silo in case the pipe conveyor is down for maintenance.

The following examples illustrate how the two-silo approach is more sustainable and environmentally friendly than alternative options:

• The gypsum is directly put onto the pipe conveyor using far fewer conveyors and motors.
• Fewer foundations are needed to construct the facilities at the plant.
• Construction time is significantly reduced.
• Less power is required per ton of gypsum moved.
• The pipe conveyor motors are run at closer to peak efficiency reducing wasted power.
• The loading operation at the landfill can be done underground or partially underground where the operation is sheltered from the elements and where it is quieter.
• Comingling the CCR materials provides a better handling and more consistent sand like material that is more consistently packed into place in the landfill.
• The fly ash does not need to be conditioned as much and the gypsum does not need to be dewatered as much since they will be comingled in the CCR silo at the landfill. While more testing may be needed to verify the limits of this, initial tests show that the blended material is like sand and behaves predictably with less sticking.

Conclusion

For plants that need to move bottom ash, fly ash and gypsum to a landfill this concept offers the flexibility to split the storage of the material to the plant and landfill and then move it rapidly to the landfill with no restriction on rate. This will save a significant amount of operating time just to transfer the material to the landfill. Once stored in the landfill silo the truck loading operation is faster.

For large volumes of CCR to be moved over a 20 or 30-year period, this truck loading efficiency gain adds up to sizable dollar savings. The two-silo concept offers clear capital and operating cost benefits at the plant end that should be carefully considered. When the operating costs are modeled and projected over a long term project life the savings are significant for plants generating significant volumes of CCR waste. The environmental benefits are also obvious.

The Fort Calhoun Station in Nebraska was the latest nuclear plant to announce its premature closure. Photo Courtesy: Omaha Public Power District

Since 2013, eight U.S. nuclear power plants have announced plans to permanently shut down operations. The impact of those closures will be felt in the communities around them and in the pocketbooks of consumers, as grid managers and power plant operators work to replace 9,000 MWs of lost capacity.

Nuclear power accounts for 57 percent of the nation’s zero-carbon electricity, according to the U.S. Energy Information Administration.

Yet, the business of nuclear power is collapsing because the market cannot support the nation’s available capacity. A lot of low-priced natural gas-fired generation has entered the market while regional demand for power is either flat or in decline. In addition, power prices are so low that some nuclear plants can no longer cover basic operating costs. Two Illinois nuclear plants – Clinton and Quad Cities – have lost a combined $800 million over the last six years.

While the closures have brought a pall over the industry, some strides have been made to save other nuclear plants in deregulated regions. Still, more needs to be done to make sure jobs are saved, towns don’t lose a major tax base and emissions remain low, said Michael Purdie, manager of Energy and Economics at the Nuclear Energy Institute’s Policy Planning and Development Division.

Purdie said wholesale markets in the Northeast, Mid-Atlantic, Midwest and Texas place a price only on the next megawatt-hour of electricity produced in a given interval, typically five-minute intervals.

“We as an industry believe that the source of that megawatt-hour does not necessarily have the same value,” Purdie said. “You can get it from solar, wind, gas or many different sources, but nuclear produces clean baseload power at stable prices.”

A major impact of nuclear closures is felt in carbon emission levels, Purdie said. Most of the lost capacity is replaced with what is currently on the grid or new combined-cycle plants that can be quickly built. In Vermont, where Entergy shut down the 604-MW Vermont Yankee plant on Dec. 31, 2014, the capacity was replaced 1-for-1 with natural gas.

“Emissions in New England went up 7 percent year-on-year,” Purdie said. “A lot of that was due to losing Vermont Yankee.”

New England, the Mid-Atlantic and the Midwest were rocked by the polar vortex of January 2014, when power prices skyrocketed after natural gas supplies were re-routed to end users for home heating instead of power generation. Nuclear plants, however, operated at greater than 93 percent capacity factor during that time. Independent system operators and regional transmission organizations like the PJM Interconnection began reforming their capacity markets in response. PJM’s reforms in January 2015 recognized that it is not enough to simply line up generation to meet reserve margin targets, but actually maintain system reliability when it is needed most.

“PJM realized that the grid was under extreme stress during the polar vortex and that a lot of power that was supposed to be available wasn’t,” Purdie said. “Incentives and penalties weren’t strong enough to ensure reliability and performance in the most extreme events.”

Illinois is the only completely deregulated state in MISO. Illinois lawmakers were considering the Next Generation Energy Plan, which would have given nuclear plants in the state a much-needed financial boost by shifting to a zero-emission standard focused on at-risk nuclear plants. The bill would have nvested $140 million in new solar developments and rebates. However, the bill’s sponsor shelved it just as the Legislature’s spring session came to a close. As a result, Exelon announced plans to close the Clinton and Quad Cities plants by June 2018.

After Omaha Public Power District (OPPD) announced in June that it would close the 479-MW single-unit Fort Calhoun Station, NEI President and CEO Marvin Fertel said nuclear power is not being properly valued and, therefore, electricity consumers will bear the brunt.

“Leaders in state capitals and Washington must bring together policies that appropriately value all attributes of electricity generation which, if done correctly, will preserve nuclear energy facilities as part of a diversified electricity portfolio,” Fertel said.

Exelon agreed to buy the FitzPatrick nuclear plant for $110 million, keeping its doors open. Courtesy: Entergy

New York’s Clean Energy Standard

Though Illinois did not pass its emission standard, New York regulators approved its Clean Energy Standard (CES) last month. The CES requires 50 percent of New York’s electricity to come from renewable sources by 2030. It also requires all six of the state’s investor-owned utilities and other energy suppliers to buy zero-emission credits to pay for the intrinsic value of carbon-free emissions from nuclear plants. The New York State Public Service Commission estimates the CES will add less than $2 a month to the average residential customer’s bill, but the credits are estimated to be worth $965 million in the first two years.

“This is not an anti-gas movement, but one that recognizes the importance of fuel diversity as an integral part of a utility system,” said NYPSC Chair Audrey Zibelman.

The standard helped to save more than 600 jobs when Exelon announced it would buy the FitzPatrick plant in upstate New York for $110 million and keep it open. Exelon also said since the CES passed, it would reinvest $400 million to $500 million into the operations, integration and refueling expenditures of its upstate nuclear plants: Nine Mile Point 1 and 2 and Ginna, which were also at risk of closing.

“This Clean Energy Standard shows you can generate the power necessary for supporting the modern economy while combatting climate change,” Gov. Cuomo said. “Make no mistake, this is a very real threat that continues to grow by the day, and I urge all other states to join us in this fight for our very future.”

Fertel agreed that other states should follow New York’s lead.

“Gov. Cuomo and the Public Service Commission correctly acknowledge nuclear power plants as indispensable sources of emissions-free power, meriting explicit valuation by the state as a clean energy source,” Fertel said.

Bill Mohl, President of Entergy Wholesale Commodities (EWC), expressed gratitude to employees of FitzPatrick for operating the plant safely despite the uncertainties.

More Shutdowns are Looming

Unfortunately, other nuclear plants are not as lucky. Entergy said it will shut down the 680-MW Pilgrim plant in Massachusetts in May 2019. The company shut down the Vermont Yankee plant in 2014.

With those closures, Entergy is left with two merchant nuclear plants in the northern U.S. As a result, Mohl said, Entergy is looking to get out of the merchant market business and aggressively grow the regulated utility side by not buying any new nuclear assets in the deregulated regions of the Northeast and Midwest.

“Last year, we sold our combined cycle power plant in Rhode Island and we continue to pursue options for the sale of other miscellaneous merchant renewable and fossil fuel plants,” Mohl said.

Paul Dempsey, Exelon’s Communications Manager, said state and federal policymakers must find solutions that recognize nuclear’s environmental and economic benefits. The utility’s single-unit Clinton plant is set to close June 1, 2017. The dual-unit Quad Cities will close June 1, 2018. Both plants are in Illinois, where all coal-fired plants in the southern half of the state may be closed.

“The Clinton and Quad Cities plants support approximately 4,200 direct and indirect jobs and produce more than $1.2 billion in economic activity annually,” Dempsey said.

A state report found that closing the plants would increase wholesale energy costs by $439 million to $645 million each year. Conversely, keeping the plants open would save $10 billion in economic damages from higher carbon emissions over 10 years, Dempsey said.

Day & Zimmermann NPS has 27,000 employees at 26 million work hours performing maintenance, repair and upgrade work at nuclear plants, according to D&Z President Walt Sanders.

The company is looking for innovative ways to cut operational costs for its customers by saving money and operating nuclear plants safely and efficiently. Day & Zimmermann NPS developed a web-based value-add tool that allows them to find areas where savings can be achieved and then share that information with other plant sites.

“It’s a repository that allows for capturing both onetime work activity savings and repeatable work scope,” Sanders said. “We can look at the new performance results and say, ‘We executed the work for this amount, now we can set a new baseline in the upcoming cycle taking advantage of the efficiencies.'”

The single-unit Clinton plant in Illinois will close June 1, 2017. Courtesy: Exelon

Sanders hopes that by the end of the year, Day&Z can assess performance results, safety, quality and costs after outages are completed.

“We can show what we’ve been able to achieve, and then be able to celebrate when we achieve a net reduction in operating costs,” Sanders said.

Whether saving companies money or giving a nuclear plant a second chance at life, many in the U.S. nuclear industry are trying to find ways to revive this struggling industry.

Chief Editor Russell Ray contributed to this report.

GE’s 7HA gas turbine. Photo courtesy: GE Power

Inventors and scientists have been fascinated by the concept of turbine engines to create power even before Leonardo di Vinci sketched an early turbine idea in one of his famous notebooks. But, it has only been in the last 80 years that the electricity-generating potential of turbines has been realized. Now, with demands for energy rising along with calls for reduced greenhouse gas emissions, the need for cleaner more efficient next generation turbine technology is critical. With a robust research portfolio, productive partnerships, and a mandate to increase power-producing efficiencies and improve the environment for future generations, the National Energy Technology Laboratory (NETL) is shepherding innovations for improved gas turbine productivity.

The goals of turbine research at NETL and the U.S. Department of Energy (DOE) are to reduce the cost of electricity, reduce emissions, and increase turbine efficiencies. NETL’s Advanced Turbines Program addresses those goals by conducting its own intensive research while partnering with other researchers in the private sector to develop technologies that will accelerate turbine performance and efficiency beyond current state-of-the-art and reduce the risk to market for novel and advanced turbine-based power cycles. The Laboratory pursues a wide range of turbine research in five specific areas in pursuit of its goals.

Hydrogen Turbines

NETL conducts research under a DOE-sponsored a program for developing hydrogen-fueled gas turbine technology for coal-based integrated gasification combined cycle (IGCC) power generation to improve efficiency, reduce emissions, lower costs, and allow for carbon capture, utilization, and storage (CCUS). DOE expanded program applicability to industries such as refineries and steel mills. Recent funding has been used to facilitate a set of gas turbine technology advancements that will improve the efficiency, emissions, and cost performance of turbines with industrial CCUS. Efforts supporting industrial technology acceleration, application, and adaptation will also benefit the advanced hydrogen turbine development and existing machines in typical utility applications.

Turbine systems and components targeted for improvement include combustor technology, materials research, enhanced cooling technology, and coatings development. These technologies are considered key components of hydrogen turbines, which, along with other advanced energy system technologies, will combine to develop next generation of high efficiency coal-based power systems.

The Hydrogen Turbine technology area is showing that the U.S. can operate on coal-based hydrogen fuel power, increase combined cycle efficiency over the baseline, and reduce carbon dioxide and other emissions.

The Hydrogen Turbine Program is focused on further advancements to turbine technology to attain the ultimate performance targets for IGCC power plants with CCUS. NETL intends to demonstrate:

• Hydrogen-fueled turbines with 3-5 percentage improvement in combined cycle efficiency (total above baseline)
• Competitive cost of electricity for near-zero emission systems
• Hydrogen-fueled IGCC with 2 ppm NOx at the power plant exhaust

Advanced Combustion Turbines

The Advanced Combustion Turbines for combined cycle applications area is focused on components and combustion systems for advanced combustion turbines in combined cycle operation that can achieve greater than 65 percent combined cycle efficiency (LHV, natural gas benchmark) and support load following capabilities to meet the demand of a modern grid. To achieve this target, emphasis is placed on advanced turbine concepts that are fueled with natural gas and coal derived fuels, including hydrogen and syngas, and higher firing temperatures (3,100 F).

Component R&D is being conducted that will allow higher turbine inlet temperatures, manage cooling requirements, minimize leakage, advance compressor and expander aerodynamics, advance the performance of high-temperature load following combustion systems with low emissions of criteria pollutants including oxides of nitrogen (NOx), and overall lead to improved efficiency of the gas turbine machine in a combined cycle application. Projects in this topic area include research on pressure gain combustion systems, ceramic matrix composite components, and advanced turbine configurations for improved cooling and efficiency.

Pressure gain combustion (PGC) has the potential to significantly improve combined cycle performance when integrated with combustion gas turbines. While conventional gas turbine engines undergo steady, subsonic combustion, resulting in a total pressure loss, PGC uses multiple physical phenomena, including resonant pulsed combustion, constant volume combustion, or detonation, to affect a rise in effective pressure across the combustor while consuming the same amount of fuel as the constant pressure combustor. The methodology resulting in a pressure-gain across the combustor relies on the Humphrey (or Atkinson) cycle, and is seen to have great potential as a means of achieving higher efficiency in gas turbine power systems, potentially reaching 4-6 percent for simple cycle systems and 2-4 percent in combined cycle systems. Potential technical challenges include fuel injection, fuel and air mixing, backflow prevention, detonation initiation, wave directionality, maintaining a pressure gain, controlling emissions of NOx and CO, as well as unsteady heat transfer and cooling flow challenges resulting from integration with the turbine hot gas path expansion components.

The University Turbine Systems Research Program (UTSR)

NETL’s UTSR Program addresses scientific research to develop and transition advanced turbines and turbine-based systems that will operate cleanly and efficiently when fueled with coal-derived synthesis gas (syngas) and hydrogen fuels. This research focuses on the areas of combustion, aerodynamics/heat transfer, and materials.

UTSR also offers a Gas Turbine Industrial Fellowship program to recruit qualified university research students. This fellowship brings highly trained student researchers from the university to industrial gas turbine manufacturing environments. The UTSR Fellowship experience often results in the employment of highly trained professionals in the gas turbine industry working to continue the advancement of gas turbine technology.

The UTSR Program has evolved over time in response to power generation markets and DOE objectives. Evolution of objectives has involved a transition from turbines operating on natural gas to coal derived syngas to very high hydrogen fuels derived from syngas. This fuel flexibility will also allow gas turbines to be used in integrated gasification combined cycle (IGCC) applications that are configured to capture carbon dioxide (CO₂). The transition requires the development of low-emission turbine combustion technologies for this variety of fuels, improved turbine hot section flow path aero/heat transfer methods, and durable, low-cost materials for the stressing environment.

Supercritical CO₂ Based Power Cycles

The Advanced Turbines Program at NETL conducts R&D for directly and indirectly heated supercritical carbon dioxide (sCO₂) based power cycles for fossil fuel applications. The focus is on components for indirectly heated fossil fuel power cycles with turbine inlet temperature in the range of 1300 – 1400 °F (700 – 760 °C) and oxy-fuel combustion for directly heated supercritical CO₂ based power cycles.

The sCO₂ power cycle operates in a manner similar to other turbine cycles, but it uses CO₂ as the working fluid in the turbomachinery. The cycle is operated above the critical point of CO₂ so that it does not change phases (from liquid to gas), but rather undergoes drastic density changes over small ranges of temperature and pressure. This allows a large amount of energy to be extracted at high temperature from equipment that is relatively small in size. At the same power rating, sCO₂ turbines will have a nominal gas path diameter significantly smaller than utility scale combustion turbines or steam turbines.

The cycle envisioned for the first fossil-based indirectly heated application is a non-condensing closed-loop recompression Brayton cycle with heat addition and rejection on either side of the expander. In this cycle, the CO₂ is heated indirectly from a heat source through a heat exchanger, not unlike the way steam would be heated in a conventional boiler. Energy is extracted from the CO₂ as it is expanded in the turbine. Remaining heat is extracted in one or more highly efficient heat recuperators to preheat the CO₂ going back to the main heat source. These recuperators help increase the overall efficiency of the cycle by limiting heat rejection from the cycle.

Research is continuing in the areas discussed above. For example, NETL is teamed with multiple private sector companies to further develop innovative technologies for advanced turbine components and sCO₂ power cycles by selecting six projects to receive more than $30 million of research funding for up to 42 months.

In a combined power cycle, a gas turbine generates electricity and its waste heat is used to make steam that generates additional electricity via a steam turbine. Meanwhile, sCO₂ is a supercritical fluid state of carbon dioxide exhibiting properties of both a gas and a liquid. sCO₂ is also non-toxic and non-flammable. Using sCO₂ in power turbines is attractive compared to steam because of its thermal stability, allowing for higher power outputs in a smaller package. The goal of the NETL-announced research projects is to increase the efficiency of combustion turbines and sCO₂ power cycles for use in new power generation facilities.

The six projects are:

• Ceramic Matrix Composite Advanced Transition for 65 Percent Combined Cycle Efficiency-Siemens Energy, Inc., working with COI Ceramics and Florida Turbine Technologies will further develop a ceramic matrix composite design for Siemens’ Advanced Transition combustor in support of 65 percent efficient gas turbine combined cycles.
• Cooled High-Temperature Ceramic Matrix Composite Nozzles for Gas Turbines for 65 Percent Efficiency-GE Power, working with GE Global Research and Clemson University, will further develop high-temperature ceramic matrix composite turbine nozzles as an innovative component that will contribute to the DOE goal for advanced gas turbines.
• Advanced Multi-Tube Mixer Combustion for 65 Percent Efficiency-GE Power, partnering with GE Global Research, will apply an advanced version of GE’s Micro Mixer multi-tube fuel-air pre-mixer with an advanced version of Axial Fuel Staging to enable turbine inlet temperatures in excess of 3,200 °F.
• Rotating Detonation Combustion for Gas Turbines-Aerojet Rocketdyne, in partnership with the Southwest Research Institute, Purdue University, the University Alabama, the University of Michigan, the University of Central Florida, and Duke Energy will develop and demonstrate an air-breathing rotating detonation engine combustion system for power generating gas turbines.
• High-Inlet Temperature Combustor for Direct-Fired Supercritical Oxy-combustion-Southwest Research Institute, in partnership with Thar Energy, LLC; GE Global Research; Georgia Tech; and the University of Central Florida will demonstrate a directly heated 1 MWth oxy-combustion sCO₂ cycle to advance the state-of-the-art fossil-fired sCO₂ power cycles.
• Development of Low-Leakage Seals for Utility Scale sCO₂ Turbines-GE Global Research, in partnership with Southwest Research Institute, will develop turbine end seals and inter-stage seals for utility-scale sCO₂ power cycles to achieve a field-trial-ready design. The majority of the work is focused on maturing turbine end seals by testing them in new and existing facilities at increasing pressures, temperatures, and seal sizes in both air and sCO₂ environments.

In 2014, DOE funded 11 Phase I projects for research on advanced turbine components for combined cycle and supercritical based power cycle applications. The new Phase II awards listed above show the most promise in reaching the DOE goals.

Advanced Turbine Research

There are three major areas involved in NETL’s Advanced Turbine Research.

Aerodynamics/Heat Transfer-Project goals of the aero-thermo-mechanical design sector are to assess the unique operation conditions associated with hydrogen turbines and investigate design improvements for addressing these unique design spaces. Efforts are focused on reducing cooling flows, reducing sealing and leakage flow rates, reducing rotating airfoil count, increasing expansion stage areas, and increasing airfoil length. These efforts are intended to develop machines that are more efficient with a higher power output.

Combustion

The combustion program goal is to design and develop the combustion portion of the turbine leveraging the best current and advanced technologies to meet strategic system-level goals of an advanced syngas or hydrogen fueled gas turbine. Efforts are focused on the measurement and assessment of the fundamental properties of hydrogen combustion and the use of these properties to design and develop low-NOx (oxides of nitrogen) combustion systems. Several combustion technologies are under evaluation, including axial fuel staging, diffusion, hybrid forms of premixed and diffusion, and pressure gain combustion.

Materials: Thermal Barrier Coatings-The goal of the projects in the materials sector is to assess and develop thermal barrier coatings (TBCs) that can provide the performance and durability required for use in syngas- and hydrogen-fueled advanced gas turbines. Efforts are focused on identifying candidate TBC architectures and material compositions with the proper thermal, mechanical, and chemical properties for use in reducing heat flux to combustor transition pieces, stationary nozzles, and rotating airfoils. Advanced TBC and bond coat architectures are being developed to improve durability and thermal performance in the harsh environment found in the IGCC gas turbine.

Recent research in this area supported by NETL has led to a discovery that could significantly increase the efficiency of turbines in fossil fuel electricity generation. This breakthrough could reduce CO₂ emissions from power plants and help drive the clean energy economy in the U.S.

When gas turbines operate at high temperatures, they use less fuel, operate more efficiently, and enable carbon capture technologies to more effectively reduce greenhouse gas emissions. The problem is that the thermal barrier coatings protect the turbines from high heat degrade and fail when they’re exposed to temperatures that exceed 1,200°C, which is required for more efficient operations and greenhouse-gas capture.

Working under an NETL-sponsored Small Business Technology Transfer project, researchers from HiFunda LLC and the University of Connecticut successfully demonstrated that an oxide called yttrium aluminum garnet (YAG) deposited by the relatively new process “solution precursor plasma spray” (SPPS) provides a thermal barrier coating with the potential for use at 1,500 °C. That’s a 300 °C temperature advantage compared to current state-of-the-art air plasma-sprayed thermal barrier coatings.

Nine major industrial partners are now testing this technology and evaluating the process in production facilities. In addition, a new spin-off company-Solution Spray Technologies LLC, a Delaware company with operations in Connecticut-has been created to be a thermal barrier coating service provider for this new technology.

If adopted throughout the gas turbine industry, this technology could significantly increase turbine efficiency and reduce overall fuel consumption. It may also enable development of technologies for next-generation, high-temperature, high-efficiency systems that could lay the ground work for more effective carbon capture in power plants – and help to drive the clean energy economy.

NETL’s ongoing research on gas turbines is emblematic of the Laboratory’s overall mission to discover, integrate, and mature technology solutions to enhance the nation’s energy foundation and protect the environment for future generations.

Author

Gerrill Griffith is a contract technical writer for the National Energy Technology Laboratory.

I’ve subscribed to the NRC Blog for several years now, and I have to say that the agency does a great job selecting interesting topics and explaining them using simple language – while simultaneously reinforcing the NRC’s independent oversight role.

A two-part July post on defense-in-depth got me thinking about nuclear plant safety and how it’s perceived relative to personal security. A prerequisite for such a thought exercise is accepting that the only thing that is perfectly safe in this world is the thing that is never invented or used. Some level of risk – and potential threat to safety – is inherent to any application of technology. For nuclear plants, lines of defense can be implemented to reduce the risks and/or minimize the effects of a technological mishap; in other words, defense-in-depth encompasses both accident prevention and accident mitigation.

The NRC Blog post refers readers to a report that explores the evolution of defense-in-depth over the past 50+ years: Historical Review and Observations of Defense-in-Depth (NUREG/KM-0009). The report identifies a distinct shift in thinking over time. For the first 30 years of commercial nuclear power, defense-in-depth reflected a deterministic perspective – basically designing our way to safety through multiple barriers that provided diversity and redundancy to address postulated accident scenarios. In the 1990s, risk analysis and an evolving risk-informed regulatory framework recast defense-in-depth in terms of uncertainty. From this “rationalist” perspective, defense-in-depth represents the sum of provisions made to compensate for inadequacies and uncertainties regarding plant behavior in accident situations.

The yin and yang of the deterministic perspective versus the rationalist perspective continues to evolve. More recent treatments of defense-in-depth blend the two perspectives. The NRC defines defense-in-depth as: “An approach to designing and operating nuclear facilities that prevents and mitigates accidents that release radiation or hazardous materials. The key is creating multiple independent and redundant layers of defense to compensate for potential human and mechanical failures so that no single layer, no matter how robust, is exclusively relied upon…”

Interestingly, in 2012, the NRC pointed out some shortcomings with respect to defense-in-depth, noting that “after decades of use, no clear definition or criteria exist on how to define adequate defense-in-depth protections; that the concept of defense-in-depth is not used consistently, and there is no guidance on how much defense-in-depth is sufficient…” [A Proposed Risk Management Regulatory Framework, NUREG-2150].

So where does that leave us? While recognizing the lack of a perfect understanding of defense-in-depth, NRC by no means disavows its importance, reiterating that defense-in-depth is a basic element of its overall safety philosophy. We may not know everything, but by designing as best we can, by recognizing and accounting for uncertainties – and then adjusting for these uncertainties through design changes, operational procedure modifications, emergency planning capabilities, etc. – we are as prepared as possible to prevent and mitigate accidents.

So does the same defense-in-depth perspective hold true for personal safety and security? Let’s look at two everyday examples: vehicles and the internet.

For vehicles, there is clearly some defense-in-depth at play. Our cars are increasingly designed with accident prevention and mitigation in mind, considering everything from antilock brakes and backup cameras to seatbelts, airbags, and bumpers. We’ve even begun factoring uncertainties into vehicle operational safety: collision detection systems, for example, help reduce risks associated with inattentive drivers or overly aggressive drivers. However, until we restrict vehicle speed based on terrain, tire condition, weather, pavement, traffic, etc., we can’t say we’re fully accounting for uncertainties and embracing defense-in-depth.

For the internet, there also is some defense-in-depth involved, but implementation is much less rigorous and more user-dependent. Passwords are notoriously weak and most applications only have protection that’s one level deep, limiting the extent of accident prevention. While there is a degree of accident mitigation, such as limited liability if credit card information is stolen, the immediate economic impacts are often the least of your troubles. And while experts routinely emphasize the uncertainties associated with protection devices such as anti-virus software (warning everyone that they can’t catch everything), the bad guys are usually a step ahead. Yet many of us still are not in the habit of performing regular backups. In the meantime, I’m going to go back up my hard drive.

At the end of the day, I’m comfortable with the defense-in-depth applied to nuclear plant design and operation. It may not be perfect, but it is subjected to thoughtful scrutiny that drives continuous improvement.

Advancements in gas-fired generation are allowing high efficiency and flexible operation of duct-fired plants for the first time. Conventional duct-firing in combined-cycle power plants is slow to respond to fast load changes. For highly duct-fired plants, conventional technology can reduce unfired efficiency. New technologies now enable fast starting and load changing capability for duct-fired, combined-cycle plants, and the ability to achieve high unfired efficiency even in highly duct-fired plants. These capabilities are achieved by combining new technologies, including a fast duct firing system, with modifications to the steam cycle that result in increased efficiency during non-duct fired operation. A plant utilizing these technologies can increase revenue by being flexible enough to support rapid load changes and efficient enough to save fuel and reduce emissions. Technologies such as these also provide other technical advantages that increase plant dispatch rate.

Flexibility

These technologies can make a duct-fired power plant flexible for the first time ever. Plants with conventional duct firing are limited to a ramp rate of about 3 MW/min. New technologires provide an integrated plant system that allows the entire output of the plant to change load at the full ramp rate of the gas turbine, ramping at about 40 MW/minute per gas turbine. This performance is achieved through an integrated design and control approach in which equipment is sized and rated for transient operation, and the control logic is programmed to keep equipment within design limits while ramping rapidly. New available technology has been enabled by experts that evaluated and designed active components together as a system, instead of using a traditional approach of attaching independently designed parts. The resulting flexibility opens the door to using duct firing to support the rapid load swings that are occurring with increasing frequency in every region of the country.

Modified Steam Cycle for Higher Efficiency and Lower Environmental Impact

Duct firing has been used as a low-cost option to add capacity to combined-cycle power plants for nearly as long as combined-cycle gas turbines have existed. However, many plants equipped with duct firing only utilize the duct burners about 20 percent of the year.

Depending on the level of duct firing, when the duct burners aren’t dispatched the plant has unused steam turbine capacity. Use of a steam turbine that is not size-optimized to plant flow can reduce the operating efficiency of the plant. To improve plant unfired efficiency, Siemens modifies the way the steam is routed through the steam turbine in the unfired mode, enabling a more optimized flow path both fired and unfired, and high unfired efficiency even in highly duct-fired plants.

Technical Advantages Return Economic Advantages

The fast duct firing system and the modified steam cycle enable higher revenue in today’s market. Higher unfired efficiency means that more power can be generated, while consuming less fuel, which reduces operating costs. The reduction in fuel consumption also means fewer emissions from the power plant. This reduces greenhouse gas production and potentially avoids costs for emissions credits.

The fast duct firing system and higher unfired efficiency can also result in higher plant dispatch. In a conventional power plant, high duct firing can result in higher revenue in the form of increased capacity payments, or by enabling higher power production during times of high demand.

The price of this additional capacity used to be a lower un-duct-fired heat rate. This new cycle design improves unfired efficiency, which can improve the dispatch order of the plant during times of lower demand.

This flexibility also provides an additional dispatch benefit; plants are able to operate to the full base load, instead of being forced to reserve or hold back plant megawatts.

Some power plant operators in different regions are forced by either grid rules or operational requirements to operate the plant at lower than base load, in order to have 2 to 10 percent of their power available at all times. Because the power needs to be rapidly available, standard duct firing will not be able to meet this need. With the addition of a fast duct firing system, the operator is able to dispatch the entire base load of the plant and support the real-time changes in the grid with duct-fired capacity.

hese additional megawatts have been evaluated by a Siemens customer employing this technology to increase revenue upwards of 5 percent per day.