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

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."

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Houston-based ENGIE to add new wind and solar projects to Texas grid

coming soon

Houston-based ENGIE North America Inc. has expanded its partnership with Los Angeles-based Ares Infrastructure Opportunities to add 730 megawatts of renewable energy projects to the ERCOT grid.

The new projects will include one wind and two solar projects in Texas.

“The continued growth of our relationship with Ares reflects the strength of ENGIE’s portfolio of assets and our track record of delivering, operating and financing growth in the U.S. despite challenging circumstances,” Dave Carroll, CEO and Chief Renewables Officer of ENGIE North America, said in a news release. “The addition of another 730 MW of generation to our existing relationship reflects the commitment both ENGIE and Ares have to meeting growing demand for power in the U.S. and our willingness to invest in meeting those needs.”

ENGIE has more than 11 gigawatts of renewable energy projects in operation or under construction in the U.S. and Canada, and 52.7 gigawatts worldwide. The company is targeting 95 gigawatts by 2030.

ENGIE launched three new community solar farms in Illinois since December, including the 2.5-megawatt Harmony community solar farm in Lena and the Knox 2A and Knox 2B projects in Galesburg.

The company's 600-megawatt Swenson Ranch Solar project near Abilene, Texas, is expected to go online in 2027 and will provide power for Meta, the parent company of social media platform Facebook. Late last year, ENGIE also signed a nine-year renewable energy supply agreement with AstraZeneca to support the pharmaceutical company’s manufacturing operations from its 114-megawatt Tyson Nick Solar Project in Lamar County, Texas.

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.