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."

All three of Intersect Power's storage systems — Lumina I, Lumina II, and Radian — are expected to be online this year. Photo courtesy of Intersect

Houston company secures $837M for trio of Texas energy storage projects

power move

Houston-based clean energy company Intersect Power has wrapped up $837 million in financing for the construction and operation of three standalone battery energy storage systems in Texas.

The money came in the form of debt financing, construction debt, and tax equity. The projects qualify for tax credits under the federal Inflation Reduction Act. Backers of the financing include Deutsche Bank, Morgan Stanley, and affiliates of HPS Investment Partners.

All three storage systems — Lumina I, Lumina II, and Radian — are expected to be online this year. Each system will be capable of storing 320 megawatts of solar power with a two-hour duration.

“Batteries will be a vital part of the energy transition and are the perfect complement to the billions of dollars of solar generation that we are building in California and Texas,” Sheldon Kimber, founder and CEO of Intersect, says in a news release.

Kimber says the storage systems will help Intersect Power triple the size of its portfolio over the next three years.

Intersect’s portfolio features 2.2 gigawatts of solar projects that are already operating, and 2.4 gigawatt hours of storage being operated or built. The company was founded in 2016.

Intersect recently signed a deal with Tesla Energy for 15.2 gigawatt hours of Megapack battery energy storage systems. The contract, which will deliver systems for Intersect projects in Texas and California, ends in 2030.

The pilot project is a cornerstone of an extended agreement between ExxonMobil Technology and Engineering and Danbury, Connecticut-based clean energy company FuelCell Energy. Photo via exxonmobil.be

ExxonMobil extends European fuel cell pilot project

next step

The Esso fuel business of Spring-based ExxonMobil is forging ahead with a pilot project at its Dutch refinery in Rotterdam to test technology aimed at reducing carbon emissions and simultaneously generating electricity and hydrogen.

The pilot project is a cornerstone of an extended agreement between ExxonMobil Technology and Engineering and Danbury, Connecticut-based clean energy company FuelCell Energy. The deal is now set to expire at the end of 2026.

ExxonMobil and FuelCell announced the pilot project in 2023.

“The unique advantage of this technology is that it not only captures CO2 but also produces low-carbon power, heat, and hydrogen as co-products,” Geoff Richardson, senior vice president of ExxonMobil Low Carbon Solutions, said last year.

The Rotterdam facility, which opened in 1960, will be the first location in the world to test the technology. The technology eventually could be rolled out at additional ExxonMobil sites.

The European Union is among the funders of the pilot project. FuelCell is making carbonate fuel cells for the project at its manufacturing plant in Torrington, Connecticut.

The extended agreement enables FuelCell to incorporate elements of the jointly developed technology into carbon capture products currently being marketed to customers. ExxonMobil and FuelCell are working on formalizing an arrangement for selling the new technology.

“The technology, which captures carbon while simultaneously generating electricity and hydrogen, could improve the economics of carbon capture and could potentially lower the barrier to broader adoption of carbon capture in the marketplace,” according to a FuelCell news release.

FuelCell says its 10-year partnership with ExxonMobil has focused on developing technology that reduces carbon emissions from emission-intensive sectors while generating electricity and hydrogen in the process — “something that no other fuel cell technology or conventional absorption systems can do.”

Under this partnership, Home Depot customers will be able to buy Sunnova’s Adaptive Home products, which includes solar power, battery storage, and smart energy management. Photo via Sunnova

Home Depot taps Houston company as exclusive solar, battery service partner

deal's on

Houston-based clean energy company Sunnova Energy International has been tapped as the exclusive provider of solar power and battery storage services for the more than 2,000 Home Depot stores in the U.S.

Under this partnership, Home Depot customers will be able to buy Sunnova’s Adaptive Home products. The Adaptive Home line combines solar power, battery storage, and smart energy management.

Sunnova didn’t assign a value to the Home Depot deal.

“Our goal is to make clean, affordable, and reliable energy services more accessible to everyone,” Michael Grasso, executive vice president and chief revenue officer at Sunnova, says in a news release. “As utility rates continue to skyrocket across the country, weather patterns worsen, and remote work becomes more prevalent, the need for resilient, affordable, and dependable power at the home is non-negotiable.”

In 2021, Sunnova rolled out its SunSafe solar and battery storage service at 100 Home Depot stores in hurricane-prone states like Florida, Maryland, and Virginia. A year later, Sunnova made the service available to all Home Depot stores in Puerto Rico.

In 2023, Sunnova expanded the SunSafe offering to 15 Home Depot markets, encompassing about 400 stores.

Publicly traded Sunnova, founded in 2012, had 419,200 customers at the end of last year.

The company recorded revenue of $720.7 million in 2023, up from $557.7 million the previous year. Its net loss in 2023 totaled $502.4 million, up from $130.3 million in 2022.

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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."