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 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."

Shell partners with UK-based co. for hydrogen electrolyzer pilot

ultra-efficient electrolyzer

Shell Global Solutions International, a subsidiary of Shell, which maintains its U.S. headquarters in Houston, has signed a collaboration agreement with London-based Supercritical Solutions to advance Supercritical’s ultra-efficient hydrogen electrolyzer technology toward a field pilot demonstration.

In the deal, the companies will collaborate on a paid technology feasibility study that will support the evaluation and planning of the pilot demonstration, according to a news release. Supercritical Solutions’ technology aims to deliver high-efficiency renewable hydrogen at a lower cost for the industrial hydrogen market.

"Signing this collaboration agreement with Shell is a major milestone for Supercritical Solutions and an important step on our commercialisation journey,” Luke Tan, co-founder of Supercritical, said in the news release. “We are directly addressing the cost and complexity barriers facing the renewable hydrogen market. We are excited to move forward with a company like Shell, whose global leadership has been proven to accelerate innovative technologies to market.”

Supercritical’s hydrogen electrolyser technology can operate at high temperatures and pressures of up to 220 bar without the need for an external hydrogen compressor, rare-earth materials or easily degradable membranes. The technology removes the typical compression step in the process while delivering hydrogen at industry standards. It requires significantly less energy than many traditional electrolyzers and is more cost-efficient.

This recent investment builds on an ongoing relationship between Shell and Supercritical. Supercritical was founded in 2020 and was runner-up in Shell’s New Energy Challenge, which helps startups and scaleups develop sustainable technologies, in 2021. Shell Ventures then invested in Supercritical’s Series A funding round in 2024 with Toyota Ventures.

3 Houston-area companies named to Global Cleantech 100

Energized

Three Houston-area companies—Amperon, Hertha Metals and Vaulted Deep—appear on this year’s Global Cleantech 100 list.

The unranked list, generated by market intelligence and advisory firm Cleantech Group, identifies the 100 privately held companies around the world that are most likely to make a significant impact in the cleantech market over the next five to 10 years.

For the 2026 list, Cleantech Group received more than 24,000 Global Cleantech 100 nominations from nearly 60 countries. Cleantech Group scored those companies and narrowed the contenders to 264. An expert panel reviewed those nominees, and the list was whittled down to the 100 winners.

Here’s a rundown of the three Houston-area honorees:

Amperon

Founded in 2018 by Sean Kelly and Abe Stanway, Houston-based Amperon offers an AI-enabled energy forecasting and analytics platform designed to help stabilize electric grids. Amperon received undisclosed amounts of venture capital from National Grid Partners and Tokyo Gas Co. Ltd. last year and announced a recent investment from Samsung Ventures earlier this month.

Hertha Metals

Founded in 2022 by Laureen Meroueh, Conroe-based Hertha Metals provides a single-step process for producing sustainable steel. Last year, the company emerged from stealth mode and raised more than $17 million in venture capital.

Vaulted Deep

Vaulted Deep’s technology injects excess organic waste underground to remove carbon dioxide from the atmosphere. Julia Reichelstein and Omar Abou-Sayed founded the Houston-based company in 2023. Last year, the startup raised $32.3 million in venture capital. Also in 2025, Vaulted Deep signed a 12-year deal with software giant Microsoft to remove up to 4.9 million metric tons of carbon dioxide from the environment.

Vaulted Deep also made the list last year, along with Houston-based Syzygy Plasmonics and Fervo Energy. Fervo was also named the 2025 North American Company of the Year by Cleantech Group.