Solar surpasses coal to become ERCOT’s third-largest power source in 2025

by the numbers

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.

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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 Houston companies earn CleanTech Breakthrough Awards

winner, winners

Eight cleantech companies with Houston headquarters were recognized in this year’s CleanTech Breakthrough Awards program.

CleanTech Breakthrough, part of market intelligence platform Tech Breakthrough, honors innovative and influential energy, climate, and cleantech companies, products and services.

This year’s winners from Houston are:

CleanTech Analytics Company of the Year: Amperon, a provider of AI-powered energy forecasting software
Overall Hydrogen Solution of the Year: Eclipse Energy, which converts maxed-out oilfields into low-cost sources of hydrogen
Energy Production Company of the Year: Fervo Energy, a provider of geothermal power
Production Solution of the Year: Quaise Energy, a developer of a drilling system for converting traditional power stations into geothermal energy plants
Green Materials Solution of the Year: Solidec, which uses air, water, and electricity to produce chemicals
Hydrogen Production Solution of the Year: VEMA Hydrogen, a producer of renewable hydrogen
CleanTech Analytics Innovation Award: Finland-based Wärtsilä, a provider of advanced energy storage systems and services, which maintains its U.S. headquarters in Houston
Energy Production Platform of the Year: France-based energy giant TotalEnergies, which maintains its U.S. headquarters in Houston

Other Texas companies made the list, including Austin-headquartered Base Power, founded by Justin Lopas and Zach Dell. Zach Dell is the son of Austin billionaire and Houston native Michael Dell, chairman and CEO of Dell Technologies. The company recently started servicing Houston and established an office in Katy.

CleanTech Breakthrough says its annual awards program honors “the visionaries and leaders accelerating the transition to a cleaner, more sustainable future.”

“In a world increasingly focused on sustainability and environmental responsibility, innovation in clean technology has never been more critical,” said Bryan Vaughn, managing director of CleanTech Breakthrough. “This year’s winners represent the very best in ingenuity and execution, delivering solutions that not only reduce environmental impact but also drive efficiency, scalability and real-world results.”

See the full list of the 2026 winners here.

HETI's new executive director takes the helm

new leader

The Houston Energy Transition Initiative has a new executive director.

Sophia Cunningham assumed the position this month, succeeding the organization's founding executive director, Jane Stricker.

"Four years ago, I could never have imagined the opportunities, experiences and relationships this role has enabled," Strickler wrote in an address earlier this year. "I am truly grateful for the support and engagement of Houston’s business and community leaders, the visionary leadership of Bobby Tudor, Scott Nyquist, HETI Members, and the Greater Houston Partnership in creating this initiative at exactly the right moment in time. I am incredibly proud of the HETI and the Partnership team members who have delivered with purpose and passion, and I greatly appreciate Houston’s energy and climate leaders and champions who have supported my agenda, challenged my thinking, broadened my perspectives, and worked with HETI to demonstrate the power of partnership in developing, innovating and advancing the ideas and technologies needed to meet this challenge for our region and the world."

Stricker shared on LinkedIn that she has joined the advisory board of FluxPoint Energy, which launched last month during CERAWeek, in addition to her other roles at Greentown Labs, Prana Low Carbon Economy Investments and UNC Kenan-Flagler Energy Center.

Cunningham previously served as vice president at HETI, where she was responsible for efforts related to carbon capture, use and storage; methane management; community engagement and stakeholder activation. Before joining HETI, she was director of public policy at The Greater Houston Partnership.

She earned her master's in Energy Management and Systems Technology from Texas A&M University and holds a bachelor's degree from Davidson College.

“I’m honored to step into the role of Executive Director of the Houston Energy Transition Initiative at such a pivotal moment for our industry," Cunningham said over email. "Houston has the talent, infrastructure, and leadership to meet growing global energy demand while reducing emissions, and I’m excited to work alongside our members and partners to accelerate solutions that are reliable, affordable, and scalable.”

The Greater Houston Partnership launched HETI in June 2021 to "meet a Dual Challenge of producing more energy that the world needs with less emissions," according to its website.

Pattern Energy expands clean energy portfolio with acquisition of Canadian producer

acquisition closed

Clean energy and transmission infrastructure company Pattern Energy completed the acquisition of Canadian independent power producer Cordelio Power this month.

Pattern Energy, which is headquartered in San Francisco and has major operations in Houston, will now own one of the largest independent clean energy infrastructure platforms in North America, according to a release.

Pattern Energy will add approximately 1,550 megawatts of operating and in-construction assets, including 16 wind, solar and energy storage projects across the United States and Canada, as part of the deal. In addition, they have also acquired the majority of Cordelio’s development pipeline in key U.S. markets and members of Cordelio’s team.

“Closing this transaction marks a significant milestone for Pattern Energy as we continue to scale our platform to meet North America’s growing energy needs,” Hunter Armistead, CEO of Pattern Energy, said in the release. “Cordelio brings a highly complementary portfolio of quality assets and a talented team. Together, we are even better positioned to power the future.”

Currently, Pattern Energy’s portfolio includes wind, solar and energy storage projects in over 40 facilities in North America. Pattern Energy had 12,000 megawatts of operating and in-construction capacity before the deal.

The acquisition was first announced Jan. 6, 2025.

“Pattern and Cordelio share a commitment to responsible development and the communities in which we work,” Chris Hind, CEO of Cordelio Power, said in a news release. “We look forward to joining with Pattern Energy to deliver high-quality projects with expanded product offerings to support customers across more markets.”

Pattern Energy doubled down on its Houston commercial space in 2023, moving the company's development, meteorological, transmission and energy trading teams to a new office in the Montrose Collective. The company's Operations Control Center is also based in Houston.

Its Houston-based development team was assigned to work on Pattern's SunZia Transmission and Wind project in New Mexico and Arizona, expected to be one of the largest clean energy infrastructure projects in U.S. The project is targeting commercial operations this year, according to Pattern Energy's website.

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