Four Startups Aim to Change the Climate Tech Game

Repurposing oil wells and cooling via outer space are among the carbon-reduction technologies in the works

4 min read

Aerial view of blue panels on a roof

SkyCool’s cooling panels radiate heat from rooftops through Earth’s atmosphere, giving an efficiency boost to building air-conditioning systems.

SkyCool Systems

Starting a company to develop an energy technology that fights climate change is hard—a lot harder than starting a software company. But the opportunities are huge. Breakthroughs in battery technology, carbon sequestration, and other energy technologies that result in a fivefold improvement over current technology could literally change the world.

That’s what John Hennessy, Stanford professor (and former president) and chairman of Alphabet, told attendees at the Stanford Global Energy Forum, held in person this month on the Stanford University campus.

The 3 Most Overhyped Decarbonization Technologies

According to Emily Kirsch, founder and managing partner of Powerhouse Ventures, speaking at the 2022 Stanford Global Energy Forum, the most overhyped decarbonization technologies are:

  • Blockchain-based carbon management
  • Nature-based solutions: Many are just a license to pollute
  • Carbon-accounting software: The technology is just not there, despite the promises being made

“If you are building a software-based company, scaling is easy, the supply chain is simple,” Hennessy said. “It’s challenging in the energy field. It takes longer.” A typical Silicon Valley startup gets up to scale in five or seven years, he pointed out; with energy startups, investors need to think out 10 or 15 years and be patient.

“Early on,” he said, “the venture community didn’t have as much patience as necessary.” Energy entrepreneurs are desperately needed, as well as investors to back them, Hennessy and other speakers at the Energy Forum indicated.

“This is a hard problem. This is not your green kumbaya.”
—Arun Majumdar, Stanford

Said Arun Majumdar, dean of Stanford’s nascent Doerr School of Sustainability: “I don’t think we’ve had in the past a moment where all major nations have made a commitment to climate sustainability with a deadline. Do they know how to meet [these] commitments? Not really.”

“This is a hard problem,” Majumdar continued. “This is not your green kumbaya. The global transition in energy will not be trivial; we have to brace for…a 30-year marathon.”

The good news is that entrepreneurs are stepping up to the plate. The Global Energy Forum showcased a few dozen startups, mostly in pitch sessions of just 3 minutes each, though I did get a chance to catch up with a few afterward. The field included startups that aim to improve battery technology and solve the battery-materials problem, coordinate energy flow from home and car batteries to the grid and back again, gather and use data for energy and carbon management, improve solar-cell efficiency, and recycle agricultural waste.

Four startups presented particularly unique ways of addressing the challenge of reducing the use of fossil fuels.

Repurposing oil wells for battery-free energy storage

“Our mission is to clean up and convert 1 million idle oil and gas wells into 1 million hours of clean energy storage,” said Kemp Gregory, CEO of Renewell Energy, based in Bakersfield, Calif.

As someone living in California, I immediately flashed on all the oil pumpjacks I pass on the drive from the Bay Area to Los Angeles, so he didn’t have to convince me that the infrastructure exists.

“There are 2.6 million idle wells,” Gregory continued, “with an average depth of 5,000 feet.” Renewell aims to seal these wells to prevent oil and gas leakage, then install systems that lift a weight to store power and drop the weight to send it back out into the grid.

Renewell recently received a US $2.7 million grant from the U.S. Department of Energy and is currently raising a $3.3 million financing round.

Harvesting the coldness of space for greener AC

A passive, thin-film coating that takes heat from a surface—be it a solar panel, a building, or a car’s roof—and sends it off into space is the idea behind SkyCool Systems, based in Mountain View, Calif. SkyCool’s technology as pitched seemed like science fiction to me. But a later research presentation by Shanhui Fan, the engineering professor at Stanford spearheading the development of the materials, filled in some of the details. And I spoke to a researcher in the audience without any connection to the project who assured me that the physics of the idea makes sense and that it’s at least theoretically possible.

SkyCool’s approach takes advantage of the property of energy at certain wavelengths to radiate from a surface through the atmosphere all the way into outer space, cooling the surface without heating the surroundings. Fan indicated that the technology can cool by 13 °C below ambient temperature at night and by 5 °C under direct sunlight.

The company’s initial product is a panel through which pumped fluid can transfer cooling of up to 15 °F to a building’s air-conditioning or refrigeration systems, giving an efficiency boost. In some cases, SkyCool suggests, the system could replace air conditioning all together. The company has raised $4.3 million in seed funding to date, according to Crunchbase.

Making hydrogen fuel easy to transport

Green hydrogen is a promising replacement fuel where high energy density is a must, but current storage and transport technologies are problematic, requiring either high-pressure containment or an expensive liquification process.

That’s the problem David Jaramillo and his cofounders at Verne say they set out to solve when they started the Berkeley, Calif., company in 2020. They came up with what they call cryo-compressed hydrogen. Said Jaramillo: “We hit the thermodynamic optimum. We compress and we cool, but not enough to liquify.”

The company says that the cryo-compressor and lightweight storage systems they are developing are cheaper, safer, and more reliable than existing hydrogen storage systems.

With this technology, Jaramillo said, “we can double the range of today’s hydrogen-fueled trucks to diesel level.”

Verne expects to start customer pilots of its hydrogen fuel storage systems next year. The company raised an undisclosed amount of funds from Berkeley’s SkyDeck Accelerator in 2020, according to Crunchbase.

Pulling nitrogen fertilizer out of thin air

“Nitrogen in nature is produced through lightning strikes,” said Benjamin Wang. Wang’s startup, The Nitrogen Company, aims to copy that process, using a room-temperature plasma inside a mobile manufacturing unit, to produce liquid nitrogen for fertilizer with just water, electricity, and air. The process will make it unnecessary to use fossil fuels to make fertilizer, as is typical today. The company demonstrated a 30-kilowatt prototype outside the energy forum.

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