Solar represented 14 percent of energy supplied to the ERCOT electric grid in 2025. Photo via bp.com

Solar barely eclipsed coal to become the third biggest source of energy generated for the Electric Reliability Council of Texas (ERCOT) in 2025, according to new data.

In 2024, solar represented 10 percent of energy supplied to the ERCOT electric grid. Last year, that number climbed to 14 percent. During the same period, coal’s share remained at 13 percent.

From the largest to smallest share, here’s the breakdown of other ERCOT energy sources in 2025 compared with 2024:

  • Combined-cycle gas: 33 percent, down from 35 percent in 2024
  • Wind: 23 percent, down from 24 percent in 2024
  • Natural gas: 8 percent, down from 9 percent in 2024
  • Nuclear: 8 percent, unchanged from 2024
  • Other sources: 1 percent, unchanged from 2024

Combined, solar and wind accounted for 37 percent of ERCOT energy sources.

Looking ahead, solar promises to reign as the star of the ERCOT show:

  • An ERCOT report released in December 2024 said solar is on track to continue outpacing other energy sources in terms of growth of installed generating capacity, followed by battery energy storage.
  • In December, ERCOT reported that more than 11,100 megawatts of new generating capacity had been added to its grid since the previous winter. One megawatt of electricity serves about 250 homes in peak-demand periods. Battery energy storage made up 47 percent of the new capacity, with solar in second place at 40 percent.

The mix of ERCOT’s energy is critical to Texas’ growing need for electricity, as ERCOT manages about 90 percent of the electric load for the state, including the Houston metro area. Data centers, AI and population growth are driving heightened demand for electricity.

In the first nine months of 2025, Texas added a nation-leading 7.4 gigawatts of solar capacity, according to a report from data and analytics firm Wood Mackenzie and the Solar Energy Industries Association.

“Remarkable growth in Texas, Indiana, Utah and other states ... shows just how decisively the market is moving toward solar,” says Abigail Ross Hopper, president and CEO of the solar association.

Time is of the essence in getting power plants online. Getty Images

Big Tech's soaring energy demands making coal-fired power plant sites attractive

Transforming Coal Power

Coal-fired power plants, long an increasingly money-losing proposition in the U.S., are becoming more valuable now that the suddenly strong demand for electricity to run Big Tech's cloud computing and artificial intelligence applications has set off a full-on sprint to find new energy sources.

President Donald Trump — who has pushed for U.S. “energy dominance” in the global market and suggested that coal can help meet surging power demand — is wielding his emergency authority to entice utilities to keep older coal-fired plants online and producing electricity.

While some utilities were already delaying the retirement of coal-fired plants, the scores of coal-fired plants that have been shut down the past couple years — or will be shut down in the next couple years — are the object of growing interest from tech companies, venture capitalists, states and others competing for electricity.

That’s because they have a very attractive quality: high-voltage lines connecting to the electricity grid that they aren’t using anymore and that a new power plant could use.

That ready-to-go connection could enable a new generation of power plants — gas, nuclear, wind, solar or even battery storage — to help meet the demand for new power sources more quickly.

For years, the bureaucratic nightmare around building new high-voltage power lines has ensnared efforts to get permits for such interconnections for new power plants, said John Jacobs, an energy policy analyst for the Washington, D.C.-based Bipartisan Policy Center.

“They are very interested in the potential here. Everyone sort of sees the writing on the wall for the need for transmission infrastructure, the need for clean firm power, the difficulty with siting projects and the value of reusing brownfield sites,” Jacobs said.

Rising power demand, dying coal plants

Coincidentally, the pace of retirements of the nation's aging coal-fired plants had been projected to accelerate at a time when electricity demand is rising for the first time in decades.

The Department of Energy, in a December report, said its strategy for meeting that demand includes re-using coal plants, which have been unable to compete with a flood of cheap natural gas while being burdened with tougher pollution regulations aimed at its comparatively heavy emissions of planet-warming greenhouse gases.

There are federal incentives, as well — such as tax credits and loan guarantees — that encourage the redevelopment of retired coal-fired plants into new energy sources.

Todd Snitchler, president and CEO of the Electric Power Supply Association, which represents independent power plant owners, said he expected Trump's executive orders will mean some coal-fired plants run longer than they would have — but that they are still destined for retirement.

Surging demand means power plants are needed, fast

Time is of the essence in getting power plants online.

Data center developers are reporting a yearlong wait in some areas to connect to the regional electricity grid. Rights-of-way approvals to build power lines can also be difficult to secure, given objections by neighbors who may not want to live near them.

Stephen DeFrank, chairman of the Pennsylvania Public Utility Commission, said he believes rising energy demand has made retiring coal-fired plants far more valuable.

That's especially true now that the operator of the congested mid-Atlantic power grid has re-configured its plans to favor sites like retired coal-fired plants as a shortcut to meet demand, DeFrank said.

“That’s going to make these properties more valuable because now, as long as I’m shovel ready, these power plants have that connection already established, I can go in and convert it to whatever," DeFrank said.

Gas, solar and more at coal power sites

In Pennsylvania, the vast majority of conversions is likely to be natural gas because Pennsylvania sits atop the prolific Marcellus Shale reservoir, DeFrank said.

In states across the South, utilities are replacing retiring or retired coal units with gas. That includes a plant owned by the Tennessee Valley Authority; a Duke Energy project in North Carolina; and a Georgia Power plant.

The high-voltage lines at retired coal plants on the Atlantic Coast in New Jersey and Massachusetts were used to connect offshore wind turbines to electricity grids.

In Alabama, the site of a coal-fired plant, Plant Gorgas, shuttered in 2019, will become home to Alabama Power’s first utility-scale battery energy storage plant.

Texas-based Vistra, meanwhile, is in the process of installing solar panels and energy storage plants at a fleet of retired and still-operating coal-fired plants it owns in Illinois, thanks in part to state subsidies approved there in 2021.

Nuclear might be coming

Nuclear is also getting a hard look.

In Arizona, lawmakers are advancing legislation to make it easier for three utilities there — Arizona Public Service, Salt River Project and Tucson Electric Power — to put advanced nuclear reactors on the sites of retiring coal-fired plants.

At the behest of Indiana's governor, Purdue University studied how the state could attract a new nuclear power industry. In its November report, it estimated that reusing a coal-fired plant site for a new nuclear power plant could reduce project costs by between 7% and 26%.

The Bipartisan Policy Center, in a 2023 study before electricity demand began spiking, estimated that nuclear plants could cut costs from 15% to 35% by building at a retiring coal plant site, compared to building at a new site.

Even building next to the coal plant could cut costs by 10% by utilizing transmission assets, roads and buildings while avoiding some permitting hurdles, the center said.

That interconnection was a major driver for Terrapower when it chose to start construction in Wyoming on a next-generation nuclear power plant next to PacifiCorp’s coal-fired Naughton Power Plant.

Jobs, towns left behind by coal

Kathryn Huff, a former U.S. assistant secretary for nuclear energy who is now an associate professor at the University of Illinois Urbana-Champaign, said the department analyzed how many sites might be suitable to advanced nuclear reactor plants.

A compelling factor is the workers from coal plants who can be trained for work at a nuclear plant, Huff said. Those include electricians, welders and steam turbine maintenance technicians.

In Homer City, the dread of losing its coal-fired plant — it shut down in 2023 after operating for 54 years — existed for years in the hills of western Pennsylvania’s coal country.

“It’s been a rough 20 years here for our area, maybe even longer than that, with the closing of the mines, and this was the final nail, with the closing of the power plant,” said Rob Nymick, Homer City's manager. “It was like, ‘Oh my god, what do we do?’”

That is changing.

The plant's owners in recent weeks demolished the smoke stacks and cooling towers at the Homer City Generating State and announced a $10 billion plan for a natural gas-powered data center campus.

It would be the nation’s third-largest power generator and that has sown some optimism locally.

“Maybe we will get some families moving in, it would help the school district with their enrollment, it would help us with our population,” Nymick said. “We’re a dying town and hopefully maybe we can get a restaurant or two to open up and start thriving again. We’re hoping.”

Energy sources are often categorized as renewable or not, but perhaps a more accurate classification focuses on the type of reaction that converts energy into useful matter. Photo by simpson33/Getty Images

How is energy produced?

ENERGY 101

Many think of the Energy Industry as a dichotomy–old vs. new, renewable vs. nonrenewable, good vs. bad. But like most things, energy comes from an array of sources, and each kind has its own unique benefits and challenges. Understanding the multi-faceted identity of currently available energy sources creates an environment in which new ideas for cleaner and more sustainable energy sourcing can proliferate.

At a high level, energy can be broadly categorized by the process of extracting and converting it into a useful form.

Energy Produced from Chemical Reaction

Energy derived from coal, crude oil, natural gas, and biomass is primarily produced as a result of bonds breaking during a chemical reaction. When heated, burned, or fermented, organic matter releases energy, which is converted into mechanical or electrical energy.

These sources can be stored, distributed, and shared relatively easily and do not have to be converted immediately for power consumption. However, the resulting chemical reaction produces environmentally harmful waste products.

Though the processes to extract these organic sources of energy have been refined for many years to achieve reliable and cheap energy, they can be risky and are perceived as invasive to mother nature.

According to the 2022 bp Statistical Review of World Energy, approximately 50% of the world’s energy consumption comes from petroleum and natural gas; another 25% from coal. Though there was a small decline in demand for oil from 2019 to 2021, the overall demand for fossil fuels remained unchanged during the same time frame, mostly due to the increase in natural gas and coal consumption.

Energy Produced from Mechanical Reaction

Energy captured from the earth’s heat or the movement of wind and water results from the mechanical processes enabled by the turning of turbines in source-rich environments. These turbines spin to produce electricity inside a generator.

Solar energy does not require the use of a generator but produces electricity due to the release of electrons from the semiconducting materials found on a solar panel. The electricity produced by geothermal, wind, solar, and hydropower is then converted from direct current to alternating current electricity.

Electricity is most useful for immediate consumption, as storage requires the use of batteries–a process that turns electrical energy into chemical energy that can then be accessed in much the same way that coal, crude oil, natural gas, and biomass produce energy.

Energy Produced from a Combination of Reactions

Hydrogen energy comes from a unique blend of both electrical and chemical energy processes. Despite hydrogen being the most abundant element on earth, it is rarely found on its own, requiring a two-step process to extract and convert energy into a usable form. Hydrogen is primarily produced as a by-product of fossil fuels, with its own set of emissions challenges related to separating the hydrogen from the hydrocarbons.

Many use electrolysis to separate hydrogen from other elements before performing a chemical reaction to create electrical energy inside of a contained fuel cell. The electrolysis process is certainly a more environmentally-friendly solution, but there are still great risks with hydrogen energy–it is highly flammable, and its general energy output is less than that of other electricity-generating methods.

Energy Produced from Nuclear Reaction

Finally, energy originating from the splitting of an atom’s nucleus, mostly through nuclear fission, is yet another way to produce energy. A large volume of heat is released when an atom is bombarded by neutrons in a nuclear power plant, which is then converted to electrical energy.

This process also produces a particularly sensitive by-product known as radiation, and with it, radioactive waste. The proper handling of radiation and radioactive waste is of utmost concern, as its effects can be incredibly damaging to the environment surrounding a nuclear power plant.

Nuclear fission produces minimal carbon, so nuclear energy is oft considered environmentally safe–as long as strict protocols are followed to ensure proper storage and disposal of radiation and radioactive waste.

Nuclear to Mechanical to Chemical?

Interestingly enough, the Earth’s heat comes from the decay of radioactive materials in the Earth’s core, loosely linking nuclear power production back to geothermal energy production.

It’s also clear the conversion of energy into electricity is the cleanest option for the environment, yet adequate infrastructure remains limited in supply and accessibility. If not consumed immediately as electricity, energy is thus converted into a chemical form for the convenience of storage and distribution it provides.

Perhaps the expertise and talent of Houstonians serving the flourishing academic and industrial sectors of energy development will soon resolve many of our current energy challenges by exploring further the circular dynamic of the energy environment. Be sure to check out our Events Page to find the networking event that best serves your interest in the Energy Transition.


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Lindsey Ferrell is a contributing writer to EnergyCapitalHTX and founder of Guerrella & Co.

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8 must-attend Houston energy events happening in November 2026

Mark your calendars

Editor's note: The November calendar is front-loaded with events for those in Houston's energy sector. From annual summits to an expo exploring AI and energy, these are the events you'll want to register for this month.

Nov. 2 — Energy Leadership Speaker Series

Join UH Energy for a conversation with Jason Wells, Chair, President, and Chief Executive Officer of CenterPoint Energy. The Energy Leadership Speaker Series is a year-long program featuring 12 expert-led sessions covering topics from energy leadership to AI and data science in energy operations. The November topic is "Grid Modernization & The Electricity Revolution."

This event begins at 4:15 pm on November 2 at the University of Houston. Find details here.

Nov. 3-4 — Next-Gen AI for Energy Summit 2026

The summit brings together over 600 senior executives from energy, technology, policy, and investment communities worldwide to explore six strategic areas: operational optimization, digital infrastructure, finance, digital twins, risk management, cybersecurity, and AI-driven market and regulatory strategies. The summit is co-located with EnergyTech X, an invite-only forum connecting energy innovators, AI founders, startups, and investors to scale next-generation energy technologies.

This event begins Nov. 3 at the Intercontinental Houston. Register here.

Nov. 3-5: 17th Annual Operational Excellence in Oil & Gas Summit

The 17th Annual Operational Excellence in Oil & Gas Summit will focus on aligning technology, process, and workforce to balance reliability, resilience, and operational cost. It will feature case studies on AI adoption, asset management, and workforce modernization.

This event begins Nov. 3 at Norris Conference Center. Register here.

Nov. 4-5 — 2026 OPIS Global LPG Conference: Powering Global Connectivity

This November, industry leaders, traders, producers, and infrastructure stakeholders will once again converge in Houston—the world’s LPG hub—for the 2026 OPIS Global LPG Conference. The conference will cover the global LPG market, which is entering a new phase of structural evolution, and how the industry is moving from managing volume to mastering the connectivity between expanding supply hubs and global energy and petrochemical demand.

This event begins Nov. 4 at the Royal Sonesta Houston Galleria. Register here.

Nov. 4-6: SAF North America Congress 2026

The aviation and energy value chains will gather in Houston once again to help shape the future of Sustainable Aviation Fuel (SAF) in North America. The focus will be on safeguarding progress made to date and ensuring SAF remains central to energy and climate strategies.

This event begins Nov. 4 at Marriott Marquis Houston. Register here.

Nov. 11: BNEF Summit Houston 2026

The BNEF Summit Houston 2026 will explore how AI-driven demand, geopolitical tensions, and electrification are reshaping energy systems at unprecedented speed. Bringing together 600 leaders across energy, tech, digital infrastructure and finance, the summit will address the race to build power, infrastructure, and supply chains — and who will fund, deliver, and benefit from the next phase of growth.

This event takes place Nov. 11 at Post Oak Houston. Register here.

Nov. 11-12: Energy Supply Chain & Procurement Summit

For 12 years, the Energy Supply Chain and Procurement Summit has brought senior procurement, supply chain, and logistics leaders to Houston — from operators, EPCs, utilities, service and equipment providers, and the suppliers they depend on. At the 2026 summit, leaders will discuss what production growth is doing to sourcing, supplier risk, and assurance of supply, and what’s working.

This event begins Nov. 11 at Houston Marriott Uptown. Register here.

Nov. 18-19: American Data Centers & AI Conference and Exhibition 2026

Set to redefine the intersection of energy and digital infrastructure, the American Data Centers & AI Conference and Exhibition convenes in Houston for its second annual event. The event will address the increasing demand for high-performance computing and the sustainable development of AI infrastructure, which requires significant power. Participants can expect to learn about practical solutions in energy integration, modern data center design, and scalable approaches. The agenda includes presentations from leading experts, demonstrations of new technologies for thermal management and grid optimization, and detailed discussions on AI's environmental impact and how to reuse generated heat.

This event begins Nov. 18 at the Double Tree Hotel at Greenway Plaza. Register here.

Utah solar company acquires Houston projects, expands to Texas

solar deals

Utah-based solar technology and battery storage company SunPower has announced its expansion into Texas by acquiring “prime project assets” from Houston installer Green Light Solar.

As part of the deal, Green Light Solar CEO James Garrett will lead SunPower’s U.S. installation group. Garrett is based in the Houston area, according to LinkedIn.

Green Light Solar focuses on residential and commercial solar installations, battery backups and whole-home generators throughout Texas, Louisiana, Oklahoma and Colorado. As of press time, SunPower had not disclosed which specific projects or assets were included in the acquisition.

In addition to the Green Light acquisition, SunPower also announced its second strategic partnership with Fort Worth-based SOLRITE Energy, which provides solar and battery project financing and virtual power plant capabilities.

Through the partnership, SunPower plans to expand its residential solar and battery storage business and grow its virtual power plant (VPP) network in Texas.

A virtual power plant is a network of connected energy sources that can supply electricity to the grid when demand is high. The network draws on energy stored in individual residential and commercial battery systems. VPPs can also help participating homeowners generate additional revenue by selling their stored power.

“SOLRITE not only sources projects to us but also provides project funding for innovative systems with large batteries connected to a VPP, enabling power sales into the open market,” T. J. Rodgers, SunPower CEO, said in a news release. “That VPP capability provides an extra source of income that SOLRITE shares with homeowners and EPCs, making SOLRITE an attractive partner.”

SunPower will bring its sales, installation and lifetime warranty support to the partnership, while SOLRITE will provide its virtual power plant platform and solar financing capabilities, according to the release.

"Building our VPP business is a key part of SunPower’s growth strategy going forward,” Kapil Rai, EVP of Direct at SunPower, added in the release. “Our partnership with SOLRITE gives us a path to bring together customer acquisition, solar, storage deployment, and financing to develop this business in Texas and beyond.”

Solid-state generator company secures $9M in financing, names CTO

fresh financing

ATS Energy has secured a $9 million investment to help commercialize its solid-state generator technology, a representative from the company tells Energy Capital.

The Colorado-based company is a member of Houston's Greentown Labs climatech community and was named the second most-promising startup in the Innovations for Traditional Energy, Electricity, & the Grid track during CERA Week's Energy Venture Day and Pitch Competition in March.

ATS's technology converts industrial waste heat into electricity via its proprietary thermoelectric cartridges, according to a news release. The cartridges convert the otherwise wasted thermal energy directly into usable electricity with no turbine, no moving parts and no emissions.

"We have spent years building a proven track record of breakthrough technology," Doug Hudson, CEO of ATS Energy, said in the release. "What has developed over the past year is that markets are moving toward ATS Energy, said in the release. We've moved well beyond early interest to commercial commitments, active proposals and a pipeline that continues to expand across multiple industrial sectors. That puts us in a tremendous position to meet the moment in delivering energy to industry. This investment responds to real commercial opportunity, and it positions ATS Energy to scale production, meet customer demand faster, and drive commercial deployments."

According to the release, ATS plans to complete and deploy its first commercial generator using the thermoelectric cartridges by mid-2027. The company shared that it plans to begin revenue-generating operations next year, as well.

ATS has also named Edward Ganja as its new CTO. Ganja previously served as a technology advisor for ATS and spent more than 30 years at Shell, most recently as vice president of catalyst and analytical technology in Houston, according to LinkedIn.

"Having worked closely with the team as a Technology Adviser, I am thrilled to step into the Chief Technology Officer role to lead our technology strategy and advanced materials scale-up," Ganja shared in a LinkedIn post. "ATS is tackling crucial energy challenges, and I look forward to working with our talented team, partners, and industry colleagues to accelerate our commercial development and technological footprint."

A representative from the company shares that ATS has three employees in Texas, including two in Houston. The company is targeting industrial facilities, including Gulf Coast refineries and petrochemical plants, for its production model, which will leverage established manufacturing capabilities to help quickly scale its commercial pipeline.

"We are scaling manufacturing with the discipline required for commercial-grade industrial deployment, moving beyond proof-of-concept to deliver mission-critical equipment," Terry Hill, COO of ATS, added in the release. "We've been building the supply chain, identifying the right manufacturing partners and putting the processes in place to move toward repeatable production. By leveraging contract manufacturing, we can focus our capital on the technology, the product and our customers rather than building factories. Just as importantly, we're working to reduce the time between installations so we can respond to the demand we're seeing in the market."

ATS won the prestigious Earthshot Prize in the Fix Our Climate category in 2024. The Earthshot Prize, founded by Prince William, awards £1 million to five energy startups each year over a decade.