Five years after Mainspring Energy Inc. launched its fuel-flexible "linear generators" for commercial, industrial and utility customers, the stars may be aligning for a significant expansion.
The Menlo Park, California-based equipment supplier on Aug. 12 announced the formation of a strategic advisory board stacked with datacenter and power industry veterans to help navigate its next steps after raising $258 million in April and emerging as one of the winners of President Donald Trump's sweeping new budget law in July.
The board's six members have amassed decades of experience as executives and engineers at tech giants Microsoft Corp. and Google LLC, and power companies NextEra Energy Inc., DTE Energy Co., Los Angeles Department of Water and Power and Northern Virginia Electric Co-op.
"Each one of them brings a really unique view of the specific customer problem and often, locally, a specific solution that's going to work for a specific geographic location," Mainspring founder and CEO Shannon Miller said in an interview. "All those folks are in the space. They have a front row seat to utility and datacenter markets."
Incubated at a Stanford University thermodynamics laboratory over a decade ago, Mainspring's linear generators can operate on any gaseous fuel, including natural gas, renewable natural gas, biogas, propane and hydrogen.
After starting with smaller projects supplied to commercial and industrial clients, the company is making a serious play to provide larger arrays to datacenter operators in need of onsite power and to utilities seeking dispatchable generation to integrate variable renewable resources and meet rising demand.
Mainspring has raised over $800 million to advance its technology, including from Amazon.com Inc., Khosla Ventures, General Catalyst Group Management LLC and Gates Frontier LLC, the venture arm of Bill Gates.
"Part of our value proposition is rapid deployment," Miller said, pointing to typical supply timeframes of a year or less. "The fact that it's a factory-built modularized system means you don't need 100 pipefitters to build your facility. You can ship modular units and install them quickly and get up and running fast. You can start with 25 MW, 50 MW, 100 MW. So that ability to rapidly deploy ... is a huge value to many of the datacenters we're talking to."
Mainspring's generator also has "very low emissions," Miller said. By relying on a flameless reaction, temperatures remain low enough that nitrogen oxide emissions can be near zero, helping ease project permitting.
'Compelling investment'
Members of the company's new strategic advisory board touted the technology's potential.
"While Mainspring's linear generator offers efficient, on-demand power with near-zero emissions and fuel-flexibility — in itself a game-changer — what excites me most is opportunities and solutions for powering datacenters that will emerge as a result of the shift to onsite generation," Christian Belady, a member of the advisory board, said in a statement. "This will drive a more reliable, lower cost and sustainable future for digital infrastructure."
Belady retired from Microsoft in 2023 as vice president of datacenter research and development for the company's cloud infrastructure group.
"Mainspring represents a compelling investment in the future of scalable, strategically sited, flexible capacity," added John Di Donato, a former vice president at NextEra Energy Resources LLC.
Mainspring has access to long-term federal tax incentives to help support its expansion as it seeks to convert on "hundreds of megawatts in development," Miller said.
Trump's budget bill, which phases out tax credits for wind and solar over the next few years, maintained or created long-term incentives for other technologies, including battery storage, geothermal, fuel cells and Mainspring's linear generators. Starting in 2026, Mainspring's technology will qualify for Section 48E investment tax credits for the next 10 years.
Meanwhile, the company is working to scale up its manufacturing site in Monterrey, Mexico, to 325 MW per year, and it is considering a new plant near Pittsburgh, contingent on an $87 million federal grant awarded by the Biden administration.
It was the largest of a $428 million tranche of funding awards for cleantech manufacturing in communities whose economies were previously closely linked to coal.
"We're still waiting to find out more certainty around that grant, but our goal is to continue to expand," Miller said.
