The voluntary framework is meant to establish a “shared, credible way” to define flexibility from large loads (particularly data centers) based on the magnitude, timing, duration and frequency of their response. By enabling a common understanding of what flexibility a load can deliver, EPRI argues the framework could help shorten interconnection timelines, improve grid planning confidence and accelerate access to power without compromising reliability or affordability.

“As demand from AI and data centers grows at unprecedented speed, flexibility is becoming the third leg of the speed-to-power stool, alongside generation and transmission,” said EPRI President and CEO Arshad Mansoor. “This framework allows everyone — utilities, regulators, and large‑load developers — to have common language about flexibility and to trust what that language means. That shared understanding is essential to moving faster while maintaining reliability.”

Data center construction and the advent of artificial intelligence (AI) are driving unprecedented electric load growth across the United States. Massive hyperscalers with deep pockets and bold aspirations need power, and they need it fast.

From May 12-14, 2026, DTECH Data Centers & AI will assemble utilities, engineers, and technical decision-makers from across this emerging ecosphere in Scottsdale, Arizona, to discuss everything from capacity constraints to streamlining studies, from modernizing infrastructure to integrating onsite generation into both utility and customer-side systems.

Register for DTECH Data Centers & AI now before early-bird pricing ends on April 1, 2026.

The framework defines flexibility through practical performance characteristics, including how quickly a load can respond, how long adjustments can last and how much power can be reduced or shifted. These characteristics are organized into a set of uniform flexibility classes that utilities, system operators and data centers can apply consistently across regions.

The framework is meant to provide a technical foundation that jurisdictions and market participants can adapt to their local needs. “As large, flexible loads play a growing role in the power system, having clear, technically grounded definitions of flexibility is critical for reliability,” said North American Electric Reliability Corporation President Jim Robb. “A common framework like this can help system operators and planners speak the same language, essential for maintaining a reliable grid.”

“As demand from data centers accelerates, state regulators are focused on ensuring customers are not burdened by the costs of serving new, large loads, as well as maintaining grid reliability,” said NARUC President Ann Rendahl. “NARUC looks forward to engaging with EPRI and others on how a voluntary, standardized framework like Flex MOSAIC can create a common language and shared understanding of flexibility, and provide benefits to state regulators when evaluating data center integration, without shifting costs to customers or compromising grid reliability.”

Initial framework participants include Alliant Energy, Arizona Public Service, California ISO, El Centro Nacional de Control de Energía (CENACE), Compass Datacenters, Constellation Energy, DTE Energy, Entergy, Exelon, Georgia Transmission Corporation, Google, Honeywell, Independent Electricity System Operator (IESO), ING, Jenbacher, Korea Power Exchange (KPX), KPMG, LG Pado, Lincoln Electric System, Lower Colorado River Authority, Meta, Midcontinent Independent System Operator (MISO), Nebraska Public Power District, NERC, NVIDIA, Portland General Electric, PSEG, Rayburn Electric, Salt River Project, Siemens, Southern Company, Southwest Power Pool and United Power.

The Call for Content for POWERGEN 2027 is now open. Submissions will be accepted through May 18, 2025. Late submissions will not be considered.

Submit Now | POWERGEN Topics & Call for Content FAQ

POWERGEN is looking for engineers, plant managers, project developers, executives and technical experts who have done the work (and have something real to say about it). Our conference educational program is built on case studies, field experience, hard-won lessons and the latest market intelligence, not promotional presentations. If your team navigated a difficult outage, executed a complex project, solved a persistent reliability problem or deployed a new technology in a demanding operating environment, this is your platform.

Utilities, IPPs, EPCs and engineering firms, OEMs, O&M service providers, self-generators and large energy users are all encouraged to submit. Owner-operator participation is strongly valued, and the POWERGEN advisory committee gives significant weight to submissions that feature this perspective.

Why This Moment Matters

The power sector is under more pressure than it has been in a generation. Load growth, driven by data centers, industrial expansion and electrification, is outpacing the pace at which new generation can be permitted, financed and built. Retirements are accelerating. Reliability margins are tightening. Supply chains that were already strained are now being tested further by compressed project timelines and competing demand for equipment, labor and engineering capacity.

At the same time, new technologies are moving from concept toward early deployment. Advanced nuclear, long-duration storage, carbon capture and AI-driven plant analytics are no longer distant possibilities — they are active decisions for owner-operators and developers right now. The industry needs honest, practitioner-led analysis of what is working, what is not and what others should know before they commit capital or change course.

POWERGEN 2027 is being designed to meet that moment. The program will be shaped by the people closest to the work.

What POWERGEN Is Looking For

Submissions should be practical, non-commercial and decision-useful. The advisory committee is looking for content that helps professionals make better decisions about how assets are built, operated, maintained and improved. Strong proposals are focused on execution, performance, reliability, cost, schedule, compliance, digitalization or other specific challenges shaping real projects and real plants.

The strongest submissions share a common structure: here is the problem, here is what we did, here is what we learned, and here is what you can apply. Proposals that deliver that arc — with specificity, candor and technical grounding — are the ones that get selected and the ones that audiences remember.

Vendor-only submissions are considered but must clear a high bar for technical rigor and industry value. The program is not a venue for product promotion or company marketing.

Topics POWERGEN Is Prioritizing in 2027

See all topics with descriptions here

POWERGEN 2027 will cover a broad range of topics spanning market conditions, project development and delivery, generation technologies, plant operations, and digital transformation. The following areas reflect the most pressing issues the industry is working through right now:

Market Drivers and Planning

Electricity demand growth is reshaping everything: development pipelines, dispatch strategies, resource adequacy decisions and investment priorities. POWERGEN is looking for submissions that examine how load growth, including the surge from data centers, is changing how utilities and power producers plan their portfolios.

Related topics include resource and capacity planning in constrained markets, interconnection strategy (now one of the most important gating factors in any development decision), onsite and behind-the-meter power for large energy users, and the practical effects of evolving federal and state policy on generation investment and operations.

Plant O&M, Reliability and Performance

For many attendees, the operations and maintenance content is the core of POWERGEN. This is where practitioners share the hardest-won lessons from running, fixing and improving generation assets in a market that demands more flexibility, more uptime and tighter cost control than ever before.

POWERGEN is looking for submissions on reliability programs, outage planning and execution, lifecycle and asset management decisions, rotating equipment performance, electrical and balance-of-plant systems, efficiency and heat rate improvement, emissions compliance and control system performance. Upgrade strategies that increase output or improve reliability from existing sites are also a priority, particularly as new capacity takes longer to bring online.

Project Development and Delivery

POWERGEN 2027 introduces a dedicated Project Development and Delivery topic area to feature the experiences of EPCs, engineering firms and developers navigating a projected power generation buildout unlike anything the sector has seen in decades. This is a new and deliberate addition to the program, reflecting how central execution risk has become to every major capacity decision.

POWERGEN is actively seeking submissions from EPCs and engineering firms on how projects move from concept to commercial operation in today’s environment. This includes siting, permitting, contracting, procurement, engineering sequencing, risk management and schedule discipline.

Related areas include EPC and EPCM contracting strategy and risk allocation, supply chain and procurement challenges across new builds and major upgrades, and permitting, siting and community engagement realities for projects under development. The emphasis is on execution lessons: what practices, structures and decisions have helped projects advance or recover when conditions changed.

Generation Technologies

POWERGEN covers the full range of generation technologies in active deployment and active consideration across the industry. Submissions are welcome across all of the following areas:

• Gas turbine and combined cycle — new build execution, major maintenance, performance tuning, uprates, fuel strategy, emissions compliance and cycling impacts
• Steam cycle and HRSG — inspection, chemistry, failure prevention, bypass systems and maintenance strategy as plants operate more dynamically
• Boilers — combustion performance, tube failures, materials issues, life extension and emissions-related upgrades
• Nuclear — uprates, license extensions, unretirements, outage performance and capital planning for both the existing fleet and new build considerations
• SMRs and advanced reactors — licensing, siting, supply chain readiness, first-of-a-kind development lessons and owner-operator interest
• Hydropower — equipment upgrades, dam safety, operational optimization, relicensing and modernization strategy
• Solar PV — project development, hybrid integration, interconnection, O&M and supply chain considerations
• Wind — turbine technology, O&M, repowers, reliability and integration with broader portfolios
• Geothermal — project development, drilling and subsurface risk, power cycle design and financing
• Energy storage and hybrid configurations — integration, controls, dispatch strategy and project economics
• Long-duration energy storage — technology evaluation, use cases, economics and integration challenges
• Carbon capture and sequestration — capture technologies, project development, permitting, economics and integration with thermal assets
• Hydrogen and alternative fuels — fuel blending, combustion impacts, infrastructure, storage and retrofit considerations
• Cogeneration and combined heat and power — technology choices, thermal integration, fuel strategy and operating economics
• Microgrids — design, controls, islanding capability, generation mix, storage integration and utility coordination

POWERGEN 2027 is scheduled for January 18-21, 2027, at the Salt Palace Convention Center in Salt Lake City, Utah.

Data centers have become modern megaliths in a new world of infrastructure powering the next wave of innovation, and artificial intelligence (AI) is redefining how they’re designed and powered. As AI workloads intensify, they’re creating new demands for efficiency, resilient power delivery, and how we define energy strategies that will determine the future of digital infrastructure.

“Data centers have become the places where AI model training and deployment occur, and that role is central to recent growth in electricity demand,” cites The International Energy Agency (IEA).¹ Because so much of the load is IT equipment, the IEA also points out that “Servers account for around 60% of electricity demand in modern data centers, underscoring why power has become such a hot topic when it comes to global growth in technology.”

Those power needs are colliding with practical limits on grid expansion. Building new transmission or waiting for interconnection approvals can take years, so data-center owners are combining strategies to secure capacity quickly. Many remain grid‑connected while signing long‑term renewable energy contracts and adding battery back-up to smooth short‑term variability. As McKinsey & Company explains, “Operators are pairing grid connections with behind‑the‑meter solutions, hybrid systems and advanced controls to handle fast-growing demand and interconnection constraints.”³ Where speed-to-power is more urgent, some operators install behind‑the‑meter generation—often modular gas turbines or generator sets—because on‑site assets can deliver capacity faster than waiting for grid upgrades. Siemens Energy captures this point plainly: “One solution to this challenge facing the data center industry is on-site generation of electricity and cooling.”⁶

Batteries are now a standard part of that toolbox. They provide immediate response during disturbances and shave short peaks so mechanical generators aren’t taxed beyond what they are designed to do. As the article by Facilities Dive observed, “Flexible battery or generator solutions can help data centers power up faster, reduce grid impacts and keep their owners’ sustainability goals within reach.”⁸ In short, hybrid mixes of grid power, long‑term renewable purchases, batteries and on‑site generation are practical and increasingly common.

Power generation equipment is not immune from these changes. Power plants tasked with serving AI loads may be asked to cycle more often and operate across a wider load range than many traditional baseload or peaking plants—behavior that increases thermal and mechanical stress on turbines, generators, and the gear drives linking them. McKinsey & Company highlights the problem in their online article, “Power supply is becoming an issue in markets that have traditionally attracted clusters of data centers, which is driving interest in dedicated generation and hybrid systems.”⁴ That means gear designs need to cope with more starts/stops, ramping, and generally more variable torque profiles than in historical applications.

With these increased demands, availability and predictability have become even more critical when it comes to power generation. Data centers expect near‑continuous operation, and backup systems are fundamental to achieving that availability. The Lawrence Berkeley Lab report states plainly that “UPS batteries and backup generators are there to keep the data center powered during outages and that these systems are essential to ensure the extremely high levels of reliability that data centers must meet.”² For gear suppliers, that translates into customers demanding not only mechanical robustness but also rapid serviceability.

So, what should gear companies do? There are several practical moves that align product and service offerings with data-center power needs. First, emphasize durability in designs intended for high‑cycle, variable‑torque duty: stronger tooth profiles, improved bearings, advanced sealing and lubrication strategies, and conservative designs that can handle a wider thermal range to reduce risk of early failure. Second, make the product serviceable by offering rapid response offerings, like Philadelphia Gear’s Onsite Technical Services (OTS)™, and high-quality OEM parts to reduce downtime for repairs during critical outages. This includes the ability to serve mobile power solutions deployed from trailers in addition to traditional, fixed brick-and-mortar facilities. Third, add simple but reliable condition monitoring for both mechanical and lubrication systems including vibration, temperature, and acoustic instrumentation so customers can incorporate predictive‑maintenance programs. McKinsey and others point to procurement trends where buyers weigh total cost of ownership, scalability, and service readiness—factors gear companies can influence through design and aftermarket offerings.^3,4

There are also product-level opportunities beyond the gear drive itself for companies that can offer more than just off-the-shelf products and instead provide engineered system solutions. So, whether the end-user is uprating current systems, needs efficiency improvements, or does not have the expertise to build a broader power‑system solution, all of these represent a competitive opportunity for OEMs. GE Vernova and Siemens Energy both emphasize the value of integrated approaches that combine generation, controls, and lifecycle services for data-center power applications.^5,6

In short, AI data centers are increasing electricity demand and, importantly, changing how that power is delivered and how generation equipment should function in this new world. Gear companies that combine proven mechanical reliability with rapid service capability, and partnership-oriented equipment solutions will be best positioned to support power plants and the various on-site power solutions serving AI workloads.

“We’ve already started working with AI data centers looking for help in meeting their energy demands,” said Carl Rapp, President of Philadelphia Gear. “With over 130 years of experience supporting the energy industry, we’ve been side-by-side with our customers as their energy needs have grown and changed. And during that time, we’ve remained true to our roots as subject matter experts for critical power generation equipment. Our approach has always been to be a trusted advisor and build custom engineered products that solve specific challenges. So, whether it’s a new gear design or servicing the equipment over its lifecycle with aftermarket repair, parts, and service, we have built our business on running to and solving our customers’ most complex problems.”

Carl continued, “As a part of Timken Power Systems (TPS), Philadelphia Gear® is integrated within a network of manufacturing and service centers that provide electro-mechanical expertise for complex engineered systems that include gear drives, electric motors, generators, bearings, and control systems. For data center operators, expertise in a single discipline is no longer enough. That’s what TPS is all about, evolving alongside our customers’ needs to deliver broader, integrated capabilities that simplify operations and help their businesses run more efficiently.”

To learn more about Philadelphia Gear or TPS, visit our websites or scan the QR code to take a virtual tour.

Authors: Carl Rapp, president of Philadelphia Gear; and Rob Fisher, marketing & product manager for Philadelphia Gear.

References

1. IEA — Energy and AI: Energy demand from AI: https://www.iea.org/reports/energy-and-ai/energy-demand-from-ai
2. Lawrence Berkeley National Laboratory, 2024 United States Data Center Energy Usage Report: https://eta-publications.lbl.gov/sites/default/files/2024-12/lbnl-2024-united-states-data-center-energy-usage-report_1.pdf
3. McKinsey & Company — AI power: Expanding data center capacity to meet growing demand: https://www.mckinsey.com/industries/technology-media-and-telecommunications/our-insights/ai-power-expanding-data-center-capacity-to-meet-growing-demand
4. McKinsey& Company — How data centers and the energy sector can sate AI’s hunger for power: https://www.mckinsey.com/industries/private-capital/our-insights/how-data-centers-and-the-energy-sector-can-sate-ais-hunger-for-power
5. Siemens Energy — On‑site Power Generation for Data Centers (white paper): https://assets.new.siemens.com/siemens/assets/api/uuid:5d02c989-8681-4320-b4e6-5445fb1b9a60/sie-us-si-rss-data-centers-power-generation-whitepaper-en.pdf
6. GE Vernova — Gas Power Technology for Data Centers: https://www.gevernova.com/gas-power/industries/data-centers
7. Facilities Dive — Data centers seek flexible power solutions for resilience, sustainability: https://www.facilitiesdive.com/news/data-centers-seek-flexible-power-solutions-for-resilience-sustainability/753811/

The announcement was part of a broader U.S.-Japan trade and investment framework that is beginning to take concrete shape. DOE and the U.S. Department of Commerce announced the agreement with SoftBank subsidiary SB Energy and AEP Ohio.

Under the arrangement, SB Energy plans to develop 9.2 GW of natural gas generation alongside a 10 GW data center complex at the Portsmouth Site, a former uranium enrichment facility that has undergone decades of environmental remediation. SB Energy has also committed $4.2 billion to upgrade and expand transmission infrastructure in Southern Ohio in coordination with AEP Ohio.

Both the generation and grid investments are structured so that costs are not passed to ratepayers, a condition the Trump administration has termed its “Ratepayer Protection Pledge.” Excess transmission and generation capacity, officials said, would be made available to the broader grid.

The Portsmouth announcement represents the most developed iteration yet of projects tied to Japan’s $550 billion U.S. investment pledge, which was framed as part of a trade agreement lowering U.S. tariffs on Japanese imports. A February announcement had outlined the project’s scale and general configuration, but left key execution questions unresolved, including interconnection, permitting posture, fuel supply and contracting structure.

Construction is expected to begin this year, though detailed engineering, permitting and financing documentation have not been publicly released.

NextEra also announces plans for large-scale gas generation

The Ohio deal was not the only large-scale natural gas development tied to the U.S.-Japan framework announced that week. NextEra Energy confirmed March 20 that President Trump had approved development of up to 10 GW of gas-fired generation across Texas and Pennsylvania hubs.

Those projects, including a Texas site developed in coordination with Comstock Resources, would be jointly owned by U.S. and Japanese interests and operated by NextEra, pending negotiation of definitive agreements.

NextEra CEO John Ketchum said the company’s hub-based development model, which currently includes nearly 30 sites at various stages of development, is designed to compress timelines and reduce execution risk. The company is targeting approximately 40 hubs total.

Whether execution keeps pace with announcement scale remains to be seen, but the volume of committed gigawatts and named partners represents a measurable step beyond earlier, more tentative project outlines.

Texas and PJM are notably two of the fastest-growing areas for large data center development and associated electricity demand.

The proposed sale represents the largest portion of the divestitures required by the U.S. Department of Justice (DOJ) as part of its antitrust review of the Calpine transaction, including all assets required to be divested by the Federal Energy Regulatory Commission (FERC). Under the agreement, LS Power will acquire approximately 4.4 GW of predominantly natural gas–fired generation capacity located in Delaware and Pennsylvania, including the Bethlehem, York 1, York 2, Hay Road and Edge Moor Facilities. The transaction is valued at $5 billion before closing adjustments, representing an acquisition price of approximately $1,142/kW.

“This transaction is an important step in satisfying the DOJ’s requirements and advancing our path forward,” said Joe Dominguez, president and CEO of Constellation. “These are well-run facilities that will continue powering consumers and businesses for decades to come. We’re pleased to be moving ahead and expect to complete the remaining DOJ requirements later this year.”

In December 2025, Constellation announced a resolution with the DOJ that outlines a series of divestitures designed to address “competitive considerations” in PJM and other markets. The DOJ resolution followed FERC’s July 2025 approval, which required the divestiture of certain assets in PJM. The latest announcement represents the largest and most substantive element of the DOJ and FERC resolutions. Closing is conditioned upon receipt of regulatory approvals, including review by the DOJ and FERC, and other customary closing conditions.

Last January, Constellation announced plans to acquire Calpine in a cash and stock transaction valued at an equity purchase price of approximately $16.4 billion. The deal became one of the largest in the history of power generation at a time when demand for electricity has exploded. Constellation already owns and operates the largest fleet of nuclear plants in the United States. Constellation is also the largest producer of clean energy in the U.S. The company generates more than 32,400 MW of capacity, including through nuclear, gas, wind, solar and hydropower assets.

Constellation sees the deal as a chance to expand its power generation portfolio in a time a record electricity demand growth. After years of flat demand, electricity load growth forecasts have exploded, largely driven by data centers, industry and electrification.

“PJM is at the epicenter of the surge in electricity demand, and these are exactly the kind of assets the grid needs – efficient, dispatchable gas generation that can deliver reliable power around the clock,” said Paul Segal, CEO of LS Power. “LS Power has been developing, building and operating gas-fired generation for over 35 years. We expect our extensive operational experience will enable seamless integration of the assets and their employees and look forward to engaging with plant staff and the local communities around the facilities.”

The Jack Fusco Energy Center, a 606-MW natural gas fired combined cycle facility located outside Houston, Texas, is the remaining facility in the DOJ resolution agreement that has not yet been divested. The minority ownership in the Gregory Power Plant, a 385-MW natural gas fired combined cycle near Corpus Christi, Texas, was divested earlier this year.

Constellation completed its acquisition of Calpine on Jan. 7, 2026, creating the world’s largest private-sector power producer and significantly expanding its generation footprint. The asset sale announced is expected to close later this year, subject to regulatory approvals.

The companies also said emission levels achieved during the test align with their development roadmap towards the goal of a 100% ammonia-fired gas turbine, with the aim of achieving commercial deployment by 2030.

“An essential piece of the ammonia value chain is now coming into place,” said Noriaki Ozawa, IHI Managing Executive Officer and President of Resource, Energy & Environment Business Area. “Since the signing of the joint development agreement in 2024, the collaboration between our two companies has gained strong momentum, with the efforts of both teams now bearing fruit. The successful achievement of 100% ammonia combustion in a full-scale F-class gas turbine marks a major milestone and helps reinforce the decarbonization roadmap envisioned by our customers in the power sector.”

The demonstration was conducted at IHI’s purpose-built test facility, engineered to replicate GE Vernova’s F-class gas turbine operating conditions. The test facility, located at IHI’s Aioi Works facility in Hyogo, Japan and completed last summer, was engineered to test advanced combustion systems at GE Vernova’s F-class gas turbine operating conditions, including pressure, temperature, and both air and fuel flow rates.

The collaboration between the two companies includes synergies across IHI ammonia combustion expertise and GE Vernova global technical teams, and shared best practices developed at GE Vernova’s advanced combustion test facility in Greenville, South Carolina.

Ammonia, a derivative from hydrogen, does not result in any net CO₂ emissions when combusted. Ammonia is used today in industrial applications, such as fertilizer. It is also used as a carrier of hydrogen.

“The successful demonstration of running an F‑class gas turbine on 100% ammonia fuel marks a pivotal step in our journey toward a lower‑carbon energy future,” said Jeremee Wetherby, GE Vernova’s Carbon Solutions leader. “This achievement reinforces our development roadmap and underscores the strength of our collaboration with IHI. We see significant potential for ammonia as a carbon‑free combustion fuel and are energized to continue working together to help unlock its role in advancing global decarbonization.”

Monday’s announcement positions Caterpillar’s G3500 series reciprocating engine platform as core infrastructure for what Nscale said could become one of the country’s largest dedicated AI compute developments.

Under the plan, Caterpillar equipment would support 2 GW of onsite generation by the first half of 2028 at the Monarch Compute Campus in Mason County, West Virginia, giving the project a faster path to power as grid access and transmission upgrades remain a constraint for large data center loads.

Nscale said the campus would host up to 1.35 GW of AI compute capacity for Microsoft under a letter of intent tied to NVIDIA Vera Rubin NVL72 systems and the NVIDIA DSX AI Factory reference design. The company also announced it had acquired American Intelligence & Power Corp., which includes the 2,250-acre Monarch site and what Nscale described as the first state-certified AI microgrid in the U.S., with expansion potential beyond 8 GW.

It’s the latest example of a data center project being structured around large-scale onsite natural gas generation, rather than waiting solely on utility service.

In a recent report, Cleanview identified 46 U.S. data center projects representing a combined 56 GW of planned behind-the-meter power capacity, which it estimated at roughly 30% of planned U.S. data center capacity in its tracker.

The research company also said 90% of the projects it identified were announced in 2025, indicating that “Bring Your Own Power” has shifted from a niche workaround to a more mainstream development path as grid interconnection timelines lengthen.

“A year ago, behind-the-meter data center power was a curiosity, embodied by xAI’s controversial decision to truck mobile generators into Memphis,” said Cleanview. “Now it’s an increasingly common development strategy.”

Cleanview added many of the projects it identified have secured equipment partners and are already under construction.

“Projects like Monarch demonstrate how Caterpillar’s natural gas generation platforms are being deployed as core infrastructure for data centers and other power intensive applications where reliability, speed of deployment, and lifecycle performance are critical,” Melissa Busen, Caterpillar senior vice president of Electric Power, said in a statement.

Nscale said the West Virginia site would operate independently of the local grid, which it argued would avoid adding costs to existing utility customers, while preserving the option of a future grid interconnection that could allow exports. The company also said it is pursuing carbon sequestration and a design intended to reduce water use.

Kevin Clark

Kevin Clark is the editor of Factor This Power Engineering, where he reports on power generation, grid reliability and emerging trends shaping the electric sector. Kevin also leads editorial strategy for the POWERGEN conference. He previously spent a decade as a television news and digital journalist. Have a story idea? Email Kevin at kevin.clark@clarionevents.com.

Germany’s largest power producer said that flexible gas would complement its existing 13 GW U.S. renewables and battery storage portfolio, strengthening its ability to meet “soaring” power demand.

The announcement comes as part of RWE’s global corporate strategy update, which affirmed the company’s global investment plans of €35 billion ($40.38 billion USD) net from 2026 through 2031 – of which €17 billion ($19.62 billion USD) net is allocated to enable growth in the United States.

RWE executives said the company’s U.S. gas strategy is centered on flexible generation in high-growth markets where power demand is rising rapidly, particularly from data centers. The company plans to leverage already-secured grid interconnections to develop a pipeline of 15 natural gas peaking projects across target markets in MISO, WECC, PJM and ERCOT.

In remarks tied to the company’s fiscal 2025 results, CEO Markus Krebber said said RWE does not want to build gas generation into the merchant U.S. market, but instead plans to pair gas with renewables and batteries in bundled offerings for customers seeking longer-term contracted supply.

The company argues that renewables and gas capacity deployed together can “optimize land use, share infrastructure, and improve energy reliability and efficiency allowing for speed to power and specific customer needs.”

“We want to combine it as a bundle with renewable, battery and the profile and then sell it to the customer,” said Krebber, adding that the company is targeting contract structures similar to renewables deals, with much of the value contracted over 10 to 15 years.

In Q&A with analysts and investors, Krebber said RWE has not yet secured equipment for the projects, but does not view supply chain constraints as a major concern because the company’s U.S. plans are focused on peakers and engines rather than combined-cycle gas turbines, where equipment availability is tighter.

That said, the company plans to move quickly.

“Our goal is to take the first FID this year and have the first megawatts operational by the end of the decade,” said Krebber. He added that the company intends to leverage its existing U.S. renewables footprint, market presence and interconnection position as it builds out the gas strategy.

RWE has existing gas units in the U.K., Germany, the Netherlands and Turkey.

In the 1980s, the NRC licensed Palo Verde’s nuclear units to operate for 40 years. In 2011, the NRC approved APS’s renewal application to extend the operating licenses 20 years, allowing the three units to operate through the mid-2040s. Last week, APS filed a Notice of Intent to submit a Subsequent License Renewal Application to the NRC in late-2027. The application will seek to renew Palo Verde’s operating license for an additional 20 years, allowing Unit 1 to operate through 2065, Unit 2 through 2066 and Unit 3 through 2067.

A license renewal for APS would extend Palo Verde’s life to 80 years. APS is following the NRC’s established license renewal process, which has resulted in renewing licenses to 80 years for 10 stations across the country. The NRC is currently reviewing applications for three stations.  

As Arizona continues to grow and energy needs increase, in addition to seeking license extensions for Palo Verde, APS is assessing new nuclear technologies and leading a collaborative effort with Salt River Project (SRP) and Tucson Electric Power (TEP) to explore and advance additional nuclear generation in the state. In 2025, the utilities teamed up to apply for a grant with the U.S. Department of Energy for funding to support the evaluation of possible sites. While awaiting a decision, the three utilities are considering multiple types of nuclear energy solutions, including small modular reactors and large reactor projects. 

Palo Verde is unique as the only nuclear power plant in the world that does not have access to a surface body of water. It uses 100% recycled wastewater from surrounding cities for cooling. It is operated by APS and owned by seven utilities: APS, SRP, El Paso Electric, Southern California Edison (SCE), Public Service Company of New Mexico (PNM), Southern California Public Power Authority (SCPPA) and Los Angeles Department of Water and Power (LADWP).

However, these fouling mechanisms can potentially induce corrosion and leaks in condenser tubes that allow cooling water ingress to the condensate. The costs from cooling water infiltration and subsequent effects on boiler water chemistry may at times dwarf those of degraded heat transfer. In this installment, we will examine several of the primary mechanisms that initiate corrosion, and we will briefly look at one of the most troublesome issues that impurities cause in steam generators. A later series will outline the online analytical instrumentation that is important for promptly detecting chemistry upsets and for maintaining normal chemistry control in steam generators.

Corrosion influenced by microbiological fouling

Microbes enter power plant cooling water by two principal pathways: the circulating water that supplies the condenser (and auxiliary heat exchangers), and from the air, especially in open recirculating systems with cooling towers. The major microorganisms are bacteria, algae and fungi, but in condensers, bacteria are the chief concern.

Free-floating, aka planktonic, bacteria are not a direct problem, but if the organisms are allowed to settle and form sessile colonies, the situation changes radically.

When bacteria attach to surfaces, some of the numerous species immediately begin to generate a protective, polysaccharide (slime) layer. The slime collects other microorganisms and suspended solids, and deposits can rapidly accumulate as shown in Figure 2.

In Part 1 we examined how fouling restricts heat transfer and fluid flow, but sessile colony development may be even more problematic in other ways. Deposits in general can establish corrosion cells where the area beneath the deposit becomes anodic to bare metal and begins to corrode. The localized attack generates pitting and potentially through-wall penetrations in a short time frame. Beyond oxygen depletion issues is that some bacteria within a colony, such as sulfate-reducers, release metabolic byproducts, including hydrogen sulfide (H2S), that are very destructive to many metals including steels. This attack is known as microbiologically induced corrosion (MIC).

I personally witnessed a MIC case where, during a month-long scheduled maintenance outage, cooling water was allowed to remain standing in the 15,000 tubes of a condenser. At startup, plant chemists immediately discovered excessive condensate contamination, which upon further inspection turned out to be the result of thousands of pinhole leaks in the 304L stainless steel tubes. An entire tube replacement, at huge cost, was necessary. This is but one example of the importance of proper layup procedures for all water/steam touched circuits of steam generators.

From a health standpoint, heavy microbiological deposits provide a habitat for Legionella pneumophila bacteria, which have caused many illnesses and deaths around the world for decades. Space limitations prevent further discussion here, but more information is available from the Cooling Technology Institute and other organizations.

Consider another case, not related to MIC, that illustrates the potentially extreme corrosion potential of sulfides. A contractor replaced the aging Admiralty brass (70% Cu, 29% Zn, 1% Sn) tubes in a condenser with the (usually) more durable 90-10 copper-nickel alloy. Within 18 months, numerous through-wall penetrations appeared in the new condenser tubes.

Subsequent investigation revealed that the material supplier had used a sulfide-containing lubricant during fabrication but did not completely remove the lubricant before shipping the product. The sulfides attacked the tubes in many locations. As in the previous example, this condenser required a complete tube replacement.

With regard to new power plant projects, my experience over several years of reviewing combined cycle project specifications is that design engineering personnel almost automatically select either 304L or 316L stainless steel for condenser tube material, without giving any thought to the chloride content of the cooling water. Chlorides can penetrate the protective oxide layer on these austenitic stainless steels and induce pitting. Recommended chloride limits are now 200 ppm for 304L and 500 ppm for 316L.² These concentrations can easily be exceeded in cooling systems with cooling towers, where all dissolved solids “cycle up” in concentration. Corrosion is exacerbated underneath deposits.

Other mechanisms that this author has observed, and which led to condenser tube failures include:

Effects of condenser tube failures on boiler water chemistry

For high-pressure utility units, including the heat recovery steam generators (HRSGs) of modern combined cycle plants, high-purity makeup and feedwater are required to prevent deposition and corrosion in boilers and the remainder of the steam-generating network.

Table 1 below, extracted from Reference 3, illustrates the recommended impurity limits in makeup water effluent and condensed turbine steam.

Table 1. Recommended Chemistry Guidelines Extracted from Table 1, Reference 3

*These values are identical for economizer inlet samples. The units μg/kg are equivalent to parts-per-billion (ppb). In a future Power Engineering series, we will examine online chemistry instrumentation requirements for complete steam generator coverage, but this abridged table is sufficient for the following discussion.

Cooling water from a lake or river typically contains several hundred parts-per-million (ppm) of cations and anions; primarily calcium, sodium, magnesium, bicarbonate, chloride, silica and sulfate, as well as other impurities including suspended solids. The concentrations increase if the water cycles up in a cooling tower. A condenser tube leak introduces these contaminants directly to the high-purity condensate.

Numerous reactions are possible when the impurities reach the boiler, which we will examine in greater detail in the future instrumentation series for Factor This Power Engineering. However, the most problematic issue in many cases is a reaction that can readily occur underneath boiler tube deposits.

Eq. 1: MgCl₂ + 2H₂O + heat → Mg(OH)₂↓ + 2HCl

A product of this reaction is hydrochloric acid (HCl). While HCl can cause substantial corrosion in and of itself, when the compound concentrates under deposits, the reaction of the acid with iron generates hydrogen, which in turn can lead to hydrogen damage of the tubes. In this mechanism, atomic hydrogen penetrates into the metal wall and then reacts with carbon atoms in the steel to generate methane (CH4):

Eq. 2: 4H + Fe₃C → 3Fe + CH₄↑

The formation of gaseous methane and hydrogen molecules induces cracking in the steel, greatly weakening its strength.

Hydrogen damage is very troublesome because it cannot be easily detected. After hydrogen damage has occurred, the plant staff may replace tubes only to find that other tubes continue to rupture. The following case history provides a graphic example, and it also relates to the last item in the bulleted list above about operator error being a potential culprit in contamination events.

Case history

An 80 MW steam generator supplied by a 1250 psig coal-fired boiler had just come online from a scheduled maintenance outage. Laboratory personnel discovered that a condenser leak was allowing contaminants to enter the system, such that condensate total-dissolved-solids (TDS) concentrations at times reached 0.75 ppm. Although the lab staff requested that the boiler be taken offline immediately, operations management refused due to load demand issues.

The boiler was on congruent phosphate control, so lab personnel increased monitoring frequency and attempted to maintain phosphate and pH levels within recommended guidelines. After approximately three weeks, operators discovered the source of the leak and corrected the problem. Two months later, boiler waterwall tubes began to fail with alarming frequency. The unit came off numerous times for tube repairs, and in at least one instance had only been back on-line for a few hours when another tube failed.

The failures happened so regularly that plant management scheduled an emergency tube replacement during the next semi-annual outage. The repair costs were at a seven-figure level. Postmortem research showed that the failures were from hydrogen damage, as shown in Equations 1 and 2 above. This event served as a huge lesson learned to plant management about the importance of maintaining proper steam generation chemistry.

However, the problem was not caused by a condenser tube failure, per say. The condenser hotwell was equipped with a drain line connected to the cooling water outlet tunnel. At the start of the outage, an operator opened the line to drain the hotwell but then forgot to close the isolation valve before startup. Once the unit returned to service, the strong condenser vacuum pulled cooling water into the hotwell. This happenstance provided an additional valuable lesson regarding the need for and adherence to precise shutdown and startup procedures.

Looking ahead to part 5

Steam condensation greatly improves the thermodynamic efficiency of power units. However, net efficiencies in the mid-30% range are about the best that can be expected for conventional sub-critical units. Mid-40% is possible with ultra supercritical units. These not-very-impressive values are a primary reason, in this era which places much importance on energy efficiency, for the development of combined cycle and cogeneration units with net efficiencies that reach or exceed 60%. We will examine the foundation behind such better efficiencies in part 5.

References

1. Post, R., Buecker, B., and Shulder, S., “Power Plant Cooling Water Fundamentals”; pre-workshop seminar for the 37th Annual Electric Utility Chemistry Workshop, June 6-8, 2017, Champaign, Illinois.
   2. Past conversations with Dan Janikowski (ret.), former subject matter expert with Plymouth Tube Company.
   3. International Association for the Properties of Water and Steam, Technical Guidance Document: Volatile treatments for the steam-water circuits of fossil and combined cycle/HRSG power plants (2015).
   4. Buecker, B., Shulder, S., and Sieben, A., “Fossil Power Plant Cycle Chemistry”; pre-workshop seminar for the 39th Annual Electric Utility Chemistry Workshop, June 4-6, 2019, Champaign, Illinois.

About the Author

Brad Buecker currently serves as Senior Technical Consultant with SAMCO Technologies. He is also the owner of Buecker & Associates, LLC, which provides independent technical writing/marketing services. Buecker has many years of experience in or supporting the power industry, much of it in steam generation chemistry, water treatment, air quality control, and results engineering positions with City Water, Light & Power (Springfield, Illinois) and Kansas City Power & Light Company’s (now Evergy) La Cygne, Kansas, station.

Additionally, his background includes eleven years with two engineering firms, Burns & McDonnell and Kiewit, and he spent two years as acting water/wastewater supervisor at a chemical plant. Buecker has a B.S. in chemistry from Iowa State University with additional course work in fluid mechanics, energy and materials balances, and advanced inorganic chemistry. He has authored or co-authored over 300 articles for various technical trade magazines, and he has written three books on power plant chemistry and air pollution control. He is a member of the ACS, AIChE, AMPP, ASME, AWT, and he is active with Power-Gen International, the Electric Utility & Cogeneration Chemistry Workshop, and the International Water Conference. He can be reached at bueckerb@samcotech.com and beakertoo@aol.com.