Houston-based Caliche Development Partners begins doubling natural gas storage capacity and building the world’s largest helium cavern, fueled by a key Texas deal completion. Photo courtesy of Caliche

With the acquisition of its Texas business now complete, Houston-based Caliche Development Partners is moving ahead with expansion of a natural gas storage project in Beaumont.

This milestone comes after a previously announced majority investment in Caliche by New York City-based investment firm Sixth Street, which has offices in Houston, Austin, and Dallas. Sixth Street recently closed on the Texas portion of the deal, and it expects to wrap up the California portion of the deal in mid-2025.

The amount of Sixth Street’s investment in Caliche wasn’t disclosed.

Completion of the deal’s Texas component gave Caliche the go-ahead to start spending Sixth Street’s money on the Beaumont project.

Caliche already has started construction on the 14 billion-cubic-feet expansion of its Golden Triangle Storage natural gas storage facilities. Two new caverns, expected to come online in 2026 and 2027, will double total storage capacity to 28 billion cubic feet (Bcf).

The Golden Triangle Storage system connects to seven major pipelines in the Beaumont-Port Arthur area.

Meanwhile, Caliche has started construction on what’s billed as the world’s largest helium storage cavern, also located at the Golden Triangle site. This cavern is slated to begin operating in 2025, while Caliche expects its planned carbon sequestration project located just four miles west of Golden Triangle to enter the next phase of the Class VI permitting process by May 2026.

Caliche is an acquisition and development company that specializes in underground storage of natural gas, industrial gasses like hydrogen and helium, and carbon emissions. Caliche’s projects are in the Texas Gulf Coast’s Jefferson County and Northern California’s Colusa County.

Caliche says Sixth Street’s backing will enable it to expand its Golden Storage Triangle complex. Photo via calichestorage.com

Investor acquires majority stake in Houston energy storage, CCS co.

here's the deal

Investment firm Sixth Street has purchased a majority stake in Houston-based Caliche Development Partners, which focuses on buying, developing, and operating natural gas and gas storage facilities along with carbon sequestration projects.

Financial terms weren’t disclosed.

The deal includes Caliche’s Golden Triangle Storage facilities and carbon sequestration project in Beaumont, and its Central Valley Gas Storage facilities in Princeton, California.

Caliche says Sixth Street’s backing will enable it to expand its Golden Storage Triangle complex, including the addition of two natural gas caverns.

Caliche’s leadership will continue to oversee day-to-day operations and remain investors in the company. All employees in Caliche’s Texas and California offices and at its facilities are staying aboard.

“We continue to meet the growing demand for the storage of natural gas and industrial gasses, including helium and hydrogen, and provide the infrastructure for lower environmental impact forms of energy through our commitment to safety, deliverability, [and] asset integrity,” Dave Marchese, CEO of Caliche, says in a news release.

Richard Sberlati, a partner at Sixth Street, which has an office in Houston, says Caliche’s success “comes from a combined 65 years of collective storage experience, and we look forward to partnering with the company’s management as they further grow the business.”

Sixth Street’s acquisition of Caliche’s Texas business operations is expected to close in late 2024, and its acquisition of the California business operations is set to close in mid-2025.

Founded in 2016, Caliche announced in 2020 that it had arranged a $150 million debt facility with Houston-based investment firm Orion Infrastructure Capital. Two years later, Caliche gained $268 million in funding from Orion and Chicago-based asset management firm GCM Grosvenor.

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Japanese company launches solar module manufacturing at Houston-area plant

solar plant

A local subsidiary of a Japanese solar equipment manufacturer recently began producing solar modules at a new plant in Humble.

TOYO Co. Ltd.’s TOYO Solar LLC subsidiary can produce 1 gigawatt worth of solar modules per year at a 567,140-square-foot plant it leases in Lovett Industrial’s Nexus North Logistics Park on Greens Road. TOYO Solar’s next phase will accommodate 2.5 gigawatts’ worth of solar module manufacturing. The subsidiary eventually plans to expand manufacturing capacity to 6.5 gigawatts.

For now, TOYO Solar operates only one assembly line at the Humble plant. Once TOYO Solar has five assembly lines up and running, it could employ as many as 750 manufacturing workers there, according to Connect CRE.

TOYO says the plant enlarges its U.S. footprint “to be closer to the majority of its clients, meet the demand for American-made solar panels, and contribute to the growing demand for secure, sustainable energy solutions as demands on the grid continue to rise.”

Last month, TOYO purchased the remaining 24.99 percent stake in TOYO Solar to make it a wholly owned subsidiary. TOYO entered the Houston-area market through its 2024 acquisition of a majority stake in Solar Plus Technology Texas LLC.

40+ climatetech startups join Greentown, including a dozen from Houston

green team

More than 40 climatetech startups joined the Greentown Labs Houston community in the second half of 2025. Twelve hail from the Bayou City.

The companies are among a group of nearly 70 that joined the climatetech incubator, which is co-located in Houston and Boston, in Q3 and Q4.

The new companies that have joined the Houston incubator specialize in a variety of clean energy applications, from green hydrogen-producing water-splitting cycles to drones that service wind turbines.

The local startups that joined Greentown Houston include:

  • Houston-based Wise Energie, which delivers turnkey microgrids that blend vertical-axis wind, solar PV, and battery storage into a single, silent system.
  • The Woodlands-based Resollant, which is developing compact, zero-emissions hydrogen and carbon reactors to provide low-cost, scalable clean hydrogen and high-purity carbon for the energy and manufacturing sectors.
  • Houston-based ClarityCastle, which designs and manufactures modular, soundproof work pods that replace traditional drywall construction with reusable, low-waste alternatives made from recycled materials.
  • Houston-based WattSto Energy, which manufactures vanadium redox flow batteries to deliver long-duration storage for both grid-scale projects and off-grid microgrids.
  • Houston-based AMPeers, which delivers advanced, high-temperature superconductors in the U.S. at a fraction of traditional costs.
  • Houston-based Biosimo, which is developing bio-based platform chemicals, pioneering sustainable chemistry for a healthier planet and economy.
  • Houston-based Ententia, which offers purpose-built, generative AI for industry.
  • Houston-based GeoKiln Energy Innovation, which is developing a new way to produce clean hydrogen by accelerating natural geologic reactions in iron-rich rock formations using precision electrical heating.
  • Houston-based Timbergrove, which builds AI and IoT solutions that connect and optimize assets—boosting visibility, safety, and efficiency.
  • Houston-based dataVediK, which combines energy-domain expertise with advanced machine learning and intelligent automation to empower organizations to achieve operational excellence and accelerate their sustainability goals.
  • Houston-based Resonant Thermal Systems, which uses a resonant energy-transfer (RET) system to extract critical minerals from industrial and natural brines without using membranes or grid electricity.
  • Houston-based Torres Orbital Mining (TOM),which develops autonomous excavation systems for extreme environments on Earth and the moon, enabling safe, data-driven resource recovery and laying the groundwork for sustainable off-world industry.

Other startups from around the world joined the Houston incubator in the same time period, including:

More than 100 startups joined Greentown this year, according to an end-of-year reflection shared by Greentown CEO Georgina Campbell Flatter.

Flatter joined Greentown in the top leadership role in February 2025. She succeeded former CEO and president Kevin Knobloch, who stepped down in July 2024.

"I moved back to the United States in March 2025 after six years overseas—2,000 miles, three children, and one very patient husband later. Over these months, I’ve had the chance to hear from the entrepreneurs, industry leaders, investors, and partners who make this community thrive. What I’ve experienced has left me brimming with urgent optimism for the future we’re building together," she said in the release.

According to Flatter, Greentown alumni raised more than $2 billion this year and created more than 3,000 jobs.

"Greentown startups and ecosystem leaders—from Boston, Houston, and beyond—are showing that we can move further and faster together. That we don’t have to choose between more energy or lower emissions, or between increasing sustainability and boosting profit. I call this the power of 'and,'" Flatter added. "We’re working for energy and climate, innovation and scale, legacy industry and startups, prosperity for people and planet. The 'and' is where possibility expands."

NRG makes latest partnership to grow virtual power plant

VPP partners

Houston-based NRG Energy recently announced a new long-term partnership with San Francisco-based Sunrun that aims to meet Texas’ surging energy demands and accelerate the adoption of home battery storage in Texas. The partnership also aligns with NRG’s goal of developing a 1-gigawatt virtual power plant by connecting thousands of decentralized energy sources by 2035.

Through the partnership, the companies will offer Texas residents home energy solutions that pair Sunrun’s solar-plus-storage systems with optimized rate plans and smart battery programming through Reliant, NRG’s retail electricity provider. As new customers enroll, their stored energy can be aggregated and dispatched to the ERCOT grid, according to a news release.

Additionally, Sunrun and NRG will work to create customer plans that aggregate and dispatch distributed power and provide electricity to Texas’ grid during peak periods.

“Texas is growing fast, and our electricity supply must keep pace,” Brad Bentley, executive vice president and president of NRG Consumer, said in the release. “By teaming up with Sunrun, we’re unlocking a new source of dispatchable, flexible energy while giving customers the opportunity to unlock value from their homes and contribute to a more resilient grid

Participating Reliant customers will be paid for sharing their stored solar energy through the partnership. Sunrun will be compensated for aggregating the stored capacity.

“This partnership demonstrates the scale and strength of Sunrun’s storage and solar distributed power plant assets,” Sunrun CEO Mary Powell added in the release. “We are delivering critical energy infrastructure that gives Texas families affordable, resilient power and builds a reliable, flexible power plant for the grid.”

In December, Reliant also teamed up with San Francisco tech company GoodLeap to bolster residential battery participation and accelerate the growth of NRG’s virtual power plant network in Texas.

In 2024, NRG partnered with California-based Renew Home to distribute hundreds of thousands of VPP-enabled smart thermostats by 2035 to help households manage and lower their energy costs. At the time, the company reported that its 1-gigawatt VPP would be able to provide energy to 200,000 homes during peak demand.