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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Halliburton Labs adds 3 energy, materials startups to Houston incubator

green team

Three new companies have joined Halliburton Labs, the incubator for early-stage energy and hardtech startups run by Houston energy giant Halliburton.

Halliburton Labs provides the emerging companies with mentorship, industry connections, laboratory access and other resources as they work toward commercialization. The latest companies to join the incubator focus on battery materials, resource recovery and gas separation solutions to address some of the "key bottlenecks in the energy and industrial landscape," according to a news release.

The new members include:

Electroflow, a California-based company that produces lithium iron phosphate (LFP) cathode material from lithium brines through its proprietary process. LFPs are critical components in batteries used in electric vehicles, grid storage systems and industrial electrification, according to Halliburton Labs.
Osmoses, a Cambridge, Massachusetts-based company that has developed a membrane platform to reduce the energy use, cost and emissions associated with gas separations used in natural gas, hydrogen, helium and other industrial applications
SiTration Inc., another Cambridge, Massachusetts-based company that has developed electro-extraction and filtration technologies to recover critical metals like copper directly from mining waste streams more quickly and affordably. Its process has completed successful pilot projects with Tier 1 mining companies in three continents.

"Affordable and reliable molecules are essential building blocks of the energy future. Each company brings a bold, technical solution to a complex industrial challenge. We look forward to helping them scale and deploy their technologies," Andres Cabada, Halliburton Labs managing director, added in the news release.

Halliburton Labs previously added four new members from around the world —Nandina REM, Noon Energy, Proof Energy and Tidal Metals—this spring. Alumni from the incubator include Houston-based companies like NanoTech Materials, which is developing insulation and fireproofing to reduce heat transfer in buildings and outdoor infrastructure; and SolvCor, which develops water additives to improve cooling for data centers and thermal storage.

With the addition of the three new members, the incubator currently supports nine early-stage companies.

Houston companies advance 200MW green ammonia plant in South Texas

coming soon

Two global companies with a major presence in Houston are teaming up on a green ammonia plant in Port of Victoria, Texas.

Topsoe, a Danish company with operations in Houston and Bayport, Texas, has been tapped to provide ammonia synthesis technology for the project being developed by First Ammonia, a New York-based company with offices in Houston and Denmark.

The flagship 200-megawatt plant will use renewable electricity to produce green hydrogen through electrolysis, which will then be combined with nitrogen from a nearby Air Liquide pipeline to make green ammonia, according to First Ammonia. It is expected to serve both U.S. and global markets.

According to First Ammonia, every 100,000 tons of electric ammonia produced avoids approximately 240,000 tons of CO2 emissions compared to fossil ammonia

The Topsoe technology used on site is designed to be able to increase production from 10 percent to 100 percent within 30 minutes, and decrease production at a similar rate, allowing the plant to respond to fluctuations from solar- or wind-based energy sources.

“Topsoe is the world leader in ammonia synthesis, and First Ammonia is delighted to continue our partnership with them in establishing a green ammonia industry in the US and around the world,” Joel Moser, CEO of First Ammonia, said in a news release.

Topsoe has previously signed on to supply its 100-megawatt solid oxide electrolyser (SOEC) to the First Ammonia project. However, the company announced in March that it did not extend the contract after multiple delays.

The First Ammonia project was originally expected to come online by 2027 and to produce 1.1 million tonnes of green ammonia. The project is now expected to reach financial before the end of 2026, with construction slated to begin in 2027 and commercial operations launching by 2029.

“As green ammonia projects move from ambition to execution, operational flexibility becomes increasingly important,” Yassir Ghiyati, chief commercial officer at Topsoe, added in a news release. “We’re proud to support First Ammonia with technology designed to enable efficient and reliable green ammonia production. We look forward to continuing to work with the First Ammonia team to help bring this important U.S project to life.”

NASA and Houston researcher tackle climate-driven water quality risks

water watch

Climate change means far more to public health than living with hotter days. Transformations in our weather are contributing to challenges in accessing safe drinking water in some communities.

One of the most dire situations is along the US–Mexico border. The National Aeronautics and Space Administration (NASA) is seeking to address that issue with its Water Quality Applications program. An 11-researcher project led by a UTHealth Houston School of Public Health faculty member has been selected to participate.

“Drinking water is one of the most fundamental public health protections, but producing safe drinking water involves a delicate balance,” Yun Hang, assistant professor of environmental and occupational health sciences, said in a news release. Her team’s proposal was one of 93 that were submitted for funding through NASA’s Research Opportunities in Space and Earth Sciences (ROSES)-2025 program.

This is the first time that NASA has worked with a team devoted to water quality applications. The group, which includes researchers from across the nation, will use satellite observations of Earth, as well as hydrologic modeling, to potentially anticipate and act on water quality conditions as they change. Challenges addressed over the course of the three-year program, which kicked off in June, might include problems with water quality due to climate variability and increased pressure on water resources.

Hang’s team will focus on a pair of borderlands: Paso del Norte and the Rio Grande Valley.

“Working closely with El Paso Water ensures that our research addresses real operational needs while helping utilities better prepare for climate-related water quality changes and continue providing safe drinking water to communities across the Texas border region,” Hang added in the release.

She and the team will use data gathered by NASA on both past and future Earth-observing missions, which will allow them to track environmental changes that may affect source water quality. Combined with past water treatment records and hydrologic models, the team will also utilize artificial intelligence to develop predictive tools that aim to stop issues before they become larger hurdles to water safety.

Another one of the project’s goals is to create visualization tools and source water summaries that can be utilized by those without scientific expertise. The tools will be produced in English and Spanish to further broaden their accessibility.

The hope is that the materials made by the team will also go far beyond the border, with protocols that can be adapted or adopted by other areas dealing with water quality issues.

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This article originally appeared on our sister site, InnovationMap.com.

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