In January 2025, Constellation Energy Corp. announced plans to acquire Houston's Calpine Corp. Photo via LinkedIn

6 major acquisitions that fueled the Houston energy sector in 2025

2025 In Review

Editor's note: As 2025 comes to a close, we're revisiting the biggest headlines and major milestones of the energy transition sector this year. Here are six major acquisitions that fueled the Houston energy industry in 2025:

Houston-based Calpine Corp. to be acquired in clean energy megadeal

Houston's Calpine Corp. will be acquired by Baltimore-based nuclear power company Constellation Energy Corp. Photo via DOE

In January 2025, Baltimore-based nuclear power company Constellation Energy Corp. and Houston-based Calpine Corp. entered into an agreement where Constellation would acquire Calpine in a cash and stock transaction with an overall net purchase price of $26.6 billion. The deal received final regulatory clearance this month.

Investment giant to acquire TXNM Energy for $11.5 billion

Blackstone Infrastructure, an affiliate of Blackstone Inc., will acquire a major Texas electricity provider. Photo via Shutterstock

In May 2025, Blackstone Infrastructure, an investment giant with $600 million in assets under management, agreed to buy publicly traded TXNM Energy in a debt-and-stock deal valued at $11.5 billion. The deal recently cleared a major regulatory hurdle, but still must be approved by the Public Utility Commission of Texas.

Houston's Rhythm Energy expands nationally with clean power acquisition

PJ Popovic, founder and CEO of Houston-based Rhythm Energy, which has acquired Inspire Clean Energy. Photo courtesy of Rhythm

Houston-based Rhythm Energy Inc. acquired Inspire Clean Energy in June 2025 for an undisclosed amount. The deal allowed Rhythm to immediately scale outside of Texas and into the Northeast, Midwest and mid-Atlantic regions.

Houston American Energy closes acquisition of New York low-carbon fuel co.

Houston American Energy Corp. has acquired Abundia Global Impact Group, which converts plastic and certified biomass waste into high-quality renewable fuels. Photo via Getty Images.

Renewable energy company Houston American Energy Corp. (NYSE: HUSA) acquired Abundia Global Impact Group in July 2025. The acquisition created a combined company focused on converting waste plastics into high-value, drop-in, low-carbon fuels and chemical products.

Chevron gets green light on $53 billion Hess acquisition

With the deal, Chevron gets access to one of the biggest oil finds of the decade. Photo via Chevron

In July 2025, Houston-based Chevron scored a critical ruling in Paris that provided the go-ahead for a $53 billion acquisition of Hess and access to one of the biggest oil finds of the decade. Chevron completed its acquisition of Hess shortly after the ruling from the International Chamber of Commerce in Paris.

Investors close partial acquisition of Phillips 66 subsidiary with growing EV network

Two investment firms have scooped up the majority stake in JET, a subsidiary of Phillips 66 with a rapidly growing EV charging network. Photo via Jet.de Facebook.

In December 2025, Energy Equation Partners, a London-based investment firm focused on clean energy companies, and New York-based Stonepeak completed the acquisition of a 65 percent interest in JET Tankstellen Deutschland GmbH, a subsidiary of Houston oil and gas giant Phillips 66.

A unanimous settlement has been reached in Blackstone's $11.5 billion acquisition of TXNM Energy. Photo via Unsplash.

Blackstone clears major step in acquisition of TXNM Energy

power deal

A settlement has been reached in a regulatory dispute over Blackstone Infrastructure’s pending acquisition of TXNM Energy, the parent company of Texas-New Mexico Power Co. , which provides electricity in the Houston area. The settlement still must be approved by the Public Utility Commission of Texas.

Aside from Public Utility Commission staffers, participants in the settlement include TXNM Energy, Texas cities served by Texas-New Mexico Power, the Texas Office of Public Utility Counsel, Texas Industrial Energy Consumers, Walmart and the Texas Energy Association for Marketers.

Texas-New Mexico Power, based in the Dallas-Fort Worth suburb of Lewisville, supplies electricity to more than 280,000 homes and businesses in Texas. Ten cities are in Texas-New Mexico Power’s Houston-area service territory:

  • Alvin
  • Angleton
  • Brazoria
  • Dickinson
  • Friendswood
  • La Marque
  • League City
  • Sweeny
  • Texas City
  • West Columbia

Under the terms of the settlement, Texas-New Mexico Power must:

  • Provide a $45.5 million rate credit to customers over 48 months, once the deal closes
  • Maintain a seven-member board of directors, including three unaffiliated directors as well as the company’s president and CEO
  • Embrace “robust” financial safeguards
  • Keep its headquarters within the utility’s Texas service territory
  • Avoid involuntary layoffs, as well as reductions of wages or benefits related to for-cause terminations or performance issues

The settlement also calls for Texas-New Mexico Power to retain its $4.2 billion five-year capital spending plan through 2029. The plan will help Texas-New Mexico Power cope with rising demand; peak demand increased about 66 percent from 2020 to 2024.

Citing the capital spending plan in testimony submitted to the Public Utility Commission, Sebastian Sherman, senior managing director of Blackstone Infrastructure, said Texas-New Mexico Power “needs the right support to modernize infrastructure, to strengthen the grid against wildfire and other risks, and to meet surging electricity demand in Texas.”

Blackstone Infrastructure, which has more than $64 billion in assets under management, agreed in August to buy TXNM Energy in a $11.5 billion deal.

Neal Walker, president of Texas-New Mexico Power, says the deal will help his company maintain a reliable, resilient grid, and offer “the financial resources necessary to thrive in this rapidly changing energy environment and meet the unprecedented future growth anticipated across Texas.”
Houston's Calpine Corp. will be acquired by Baltimore-based nuclear power company Constellation Energy Corp. Photo via DOE

Constellation and Calpine's $26B clean energy megadeal clears final regulatory hurdle

big deal

Baltimore-based nuclear power company Constellation Energy Corp. received final regulatory clearance this month to acquire Houston-based Calpine Corp. for a net purchase price of $26.6 billion.

The acquisition has the potential to create America’s “largest clean energy provider,” the companies reported when the deal was first announced in January.

The Department of Justice approved the acquisition contingent on Calpine divesting several assets, including one in the Houston area.

The company agreed to divest the Jack Fusco Energy Center natural gas-fired combined cycle facility in Richmond, Texas; four generating assets in the Mid-Atlantic region; and other natural gas plants in Pennsylvania and Corpus Christi, Texas.

The Federal Energy Regulatory Commission, the Public Utility Commission of Texas and the New York Public Service Commission previously approved the deal. The companies can move toward closing the acquisition once the court finalizes the stipulation and order.

"We are very pleased to reach a settlement that allows us to bring together two magnificent companies to create a new Constellation with unprecedented scale, talent and capability to better serve our customers and communities while building the foundation for America’s next great era of growth and innovation," Joe Dominguez, president and CEO of Constellation, said in a news release. "We thank the Department for its professionalism and tireless work reviewing this transaction through these many months. It’s now time for us to complete the transaction, welcome our new colleagues from Calpine, and together begin our journey to light the way to a brilliant tomorrow for all."

Andrew Novotny, CEO of Calpine, will continue to lead the Calpine business and Constellation's fleet of natural gas, hydro, solar and wind generation, according to the company. He will report to Dominguez and also serve as senior executive vice president of Constellation Power Operations.

Constellation is considered one of the top clean energy producers in the U.S. Earlier this month, the company was approved to receive a $1 billion loan from the Department of Energy's Energy Dominance Financing Program to restart its 835-megawatt nuclear reactor in Pennsylvania known as Crane Clean Energy Center.

"Work to restart the reactor comes at a time of unprecedented electric demand growth from electrification and the new data centers needed to support a growing digital economy and to help America win the AI race," a news release from the company reads. "Crane will support grid stability by delivering reliable, around-the-clock electric supply."

With the deal, Chevron gets access to one of the biggest oil finds of the decade. Photo via Chevron

Chevron gets green light on $53 billion Hess acquisition

Mega Deal

Chevron has scored a critical ruling in Paris that has given it the go-ahead for a $53 billion acquisition of Hess and access to one of the biggest oil finds of the decade.

Chevron said Friday that it completed its acquisition of Hess shortly after the ruling from the International Chamber of Commerce in Paris. Exxon had challenged Chevron’s bid for Hess, one of three companies with access to the massive Stabroek Block oil field off the coast of Guyana.

“We disagree with the ICC panel’s interpretation but respect the arbitration and dispute resolution process,” Exxon Mobil said in a statement on Friday.

Guyana is a country of 791,000 people that is poised to become the world’s fourth-largest offshore oil producer, placing it ahead of Qatar, the United States, Mexico and Norway. It has become a major producer in recent years.

Oil giants Exxon Mobil, China’s CNOOC, and Hess squared off in a heated competition for highly lucrative oil fields in northern South America.

With Chevron getting the green light on Friday, it is now one of the major players in the Stabroek.

“We are proud of everyone at Hess for building one of the industry’s best growth portfolios including Guyana, the world’s largest oil discovery in the last 10 years, and the Bakken shale, where we are a leading oil and gas producer,” former Hess CEO John Hess said in a statement. “The strategic combination of Chevron and Hess creates a premier energy company positioned for the future.”

Chevron also said that on Thursday the Federal Trade Commission lifted its earlier restriction, clearing the way for John Hess to join its board of directors, subject to board approval.

Chevron announced its deal for Hess in October 2023, less than two weeks after Exxon Mobil said that it would acquire Pioneer Natural Resources for about $60 billion.

Chevron said at the time that the acquisition of Hess would add a major oil field in Guyana as well as shale properties in the Bakken Formation in North Dakota.

“Given the significant value we’ve created in the development of the Guyana resource, we believed we had a clear duty to our investors to consider our preemption rights to protect the value we created through our innovation and hard work at a time when no one knew just how successful this venture would become,” Exxon Mobil said Friday. “We welcome Chevron to the venture and look forward to continued industry-leading performance and value creation in Guyana for all parties involved.”

Chevron's stock rose more than 3% before the market open, while shares of Hess surged more than 7%. Exxon's stock climbed slightly.

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Houston geothermal company raises $97M Series B

fresh funding

Houston-based geothermal energy startup Sage Geosystems has closed its Series B fundraising round and plans to use the money to launch its first commercial next-generation geothermal power generation facility.

Ormat Technologies and Carbon Direct Capital co-led the $97 million round, according to a press release from Sage. Existing investors Exa, Nabors, alfa8, Arch Meredith, Abilene Partners, Cubit Capital and Ignis H2 Energy also participated, as well as new investors SiteGround Capital and The UC Berkeley Foundation’s Climate Solutions Fund.

The new geothermal power generation facility will be located at one of Ormat Technologies' existing power plants. The Nevada-based company has geothermal power projects in the U.S. and numerous other countries around the world. The facility will use Sage’s proprietary pressure geothermal technology, which extracts geothermal heat energy from hot dry rock, an abundant geothermal resource.

“Pressure geothermal is designed to be commercial, scalable and deployable almost anywhere,” Cindy Taff, CEO of Sage Geosystems, said in the news release. “This Series B allows us to prove that at commercial scale, reflecting strong conviction from partners who understand both the urgency of energy demand and the criticality of firm power.”

Sage reports that partnering with the Ormat facility will allow it to market and scale up its pressure geothermal technology at a faster rate.

“This investment builds on the strong foundation we’ve established through our commercial agreement and reinforces Ormat’s commitment to accelerating geothermal development,” Doron Blachar, CEO of Ormat Technologies, added in the release. “Sage’s technical expertise and innovative approach are well aligned with Ormat’s strategy to move faster from concept to commercialization. We’re pleased to take this natural next step in a partnership we believe strongly in.”

In 2024, Sage agreed to deliver up to 150 megawatts of new geothermal baseload power to Meta, the parent company of Facebook. At the time, the companies reported that the project's first phase would aim to be operating in 2027.

The company also raised a $17 million Series A, led by Chesapeake Energy Corp., in 2024.

Houston expert discusses the clean energy founder's paradox

Guest Column

Everyone tells you to move fast and break things. In clean energy, moving fast without structural integrity means breaking the only planet we’ve got. This is the founder's paradox: you are building a company in an industry where the stakes are existential, the timelines are glacial, and the capital requires patience.

The myth of the lone genius in a garage doesn’t really apply here. Clean energy startups aren’t just fighting competitors. They are fighting physics, policy, and decades of existing infrastructure. This isn’t an app. You’re building something physical that has to work in the real world. It has to be cheaper, more reliable, and clearly better than fossil fuels. Being “green” alone isn’t enough. Scale is what matters.

Your biggest risks aren’t competitors. They’re interconnection delays, permitting timelines, supply chain fragility, and whether your first customer is willing to underwrite something that hasn’t been done before.

That reality creates a brutal filter. Successful founders in this space need deep technical knowledge and the ability to execute. You need to understand engineering, navigate regulation, and think in terms of markets and risk. You’re not just selling a product. You’re selling a future where your solution becomes the obvious choice. That means connecting short-term financial returns with long-term system change.

The capital is there, but it’s smarter and more demanding. Investors today have PhDs in electrochemistry and grid dynamics. They’ve been burned by promises of miracle materials that never left the lab. They don't fund visions; they fund pathways to impact that can scale and make financial sense. Your roadmap must show not just a brilliant invention, but a clear, believable plan to drive costs down over time.

Capital in this sector isn’t impressed by ambition alone. It wants evidence that risk is being retired in the right order — even if that means slower growth early.

Here’s the upside. The difficulty of clean energy is also its strength. If you succeed, your advantage isn’t just in software or branding. It’s in hardware, supply chains, approvals, and years of hard work that others can’t easily copy. Your real competitors aren’t other startups. They’re inertia and the existing system. Winning here isn’t zero-sum. When one solution scales, it helps the entire market grow.

So, to the founder in the lab, or running field tests at a remote site: your pace will feel slow. The validation cycles are long. But you are building in the physical world. When you succeed, you don’t have an exit. You have a foundation. You don't just have customers; you have converts. And the product you ship doesn't just generate revenue; it creates a legacy.

If your timelines feel uncomfortable compared to software, that’s because you’re operating inside a system designed to resist change. And let’s not forget you are building actual physical products that interact with a complex world. Times are tough. Don’t give up. We need you.

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Nada Ahmed is the founding partner at Houston-based Energy Tech Nexus.

Houston maritime startup raises $43M to electrify cargo vessels

A Houston-based maritime technology company that is working to reduce emissions in the cargo and shipping industry has raised VC funding and opened a new Houston headquarters.

Fleetzero announced that it closed a $43 million Series A financing round this month led by Obvious Ventures with participation from Maersk Growth, Breakthrough Energy Ventures, 8090 Industries, Y Combinator, Shorewind, Benson Capital and others. The funding will go toward expanding manufacturing of its Leviathan hybrid and electric marine propulsion system, according to a news release.

The technology is optimized for high-energy and zero-emission operation of large vessels. It uses EV technology but is built for maritime environments and can be used on new or existing ships with hybrid or all-electric functions, according to Fleetzero's website. The propulsion system was retrofitted and tested on Fleetzero’s test ship, the Pacific Joule, and has been deployed globally on commercial vessels.

Fleetzero is also developing unmanned cargo vessel technology.

"Fleetzero is making robotic ships a reality today. The team is moving us from dirty, dangerous, and expensive to clean, safe, and cost-effective. It's like watching the future today," Andrew Beebe, managing director at Obvious Ventures, said in the news release. "We backed the team because they are mariners and engineers, know the industry deeply, and are scaling with real ships and customers, not just renderings."

Fleetzero also announced that it has opened a new manufacturing and research and development facility, which will serve as the company's new headquarters. The facility features a marine robotics and autonomy lab, a marine propulsion R&D center and a production line with a capacity of 300 megawatt-hours per year. The company reports that it plans to increase production to three gigawatt-hours per year over the next five years.

"Houston has the people who know how to build and operate big hardware–ships, rigs, refineries and power systems," Mike Carter, co-founder and COO of Fleetzero, added in the release. "We're pairing that industrial DNA with modern batteries, autonomy, and software to bring back shipbuilding to the U.S."