DCVC DTOR 2024: New storage and generation tech­nolo­gies will make the electrical grid cleaner and more resilient

To make the most efficient use of existing trans­mis­sion capacity — and to compensate for extreme weather events, which are growing in frequency — nations will always need ​“clean firm” power, meaning carbon-free electricity that’s available on demand when solar and wind aren’t. Here at DCVC, we’re investing in several forms of clean firm power, as well as long-term energy storage to round out the bumps in power supplies. 

First, there’s next-generation nuclear power, which we covered extensively in 2023’s Deep Tech Oppor­tu­ni­ties Report. Here in the United States we still face great challenges building new gigawatt-scale light water reactors; the Vogtle Unit 3 and 4 reactors that recently entered commercial operation in Georgia were seven years late and $17 billion over budget. We think microre­ac­tors, on the scale of 1 – 20 megawatts of thermal energy each, are more likely to achieve economic viability, and so we’ve been backing microre­actor pioneer Oklo since 2018. 

The company is developing an advanced fast neutron reactor that runs on waste fuel from conven­tional reactors. It’s an updated version of an exper­i­mental breeder reactor that operated safely for 30 years at what’s now Idaho National Laboratory. In May, the company went public through a merger with AltC, a special purpose acquisition company co-founded by OpenAI CEO Sam Altman, raising more than $300 million in new capital. Oklo plans to build plants for about $70 million per project and sell power directly to individual customers who need clean firm power, such as data centers and factories. 

Radiant, another DCVC-backed company, is developing an even smaller microre­actor, one designed to fit on the back of a semitrailer and generate about 1.2 megawatts of electricity — enough to replace the polluting diesel generators used by expe­di­tionary military forces or as backup power in remote village hospitals. Radiant’s Kaleidos reactor uses super­crit­ical CO2 for power conversion, allowing for smaller and more efficient turbines that don’t need access to water for cooling. ​“I think this will ultimately be a game changer,” says DCVC partner Dr. Rachel Slaybaugh. ​“We’ll be able to bring reliable zero-emissions power to remote locations and emergency situations, creating tremendous flexibility that’s never been possible before.” 

Then there’s a new wave of innovative projects that extract naturally occurring heat from the depths of the earth and use it to generate electricity. There are a variety of approaches to geothermal energy, and we’ve placed our bet on Fervo Energy, which in 2023 became the first company to demonstrate commercial-scale flow rates for a pair of wells — one for injecting water and another for extracting it. Fervo has adapted hydraulic fracturing, horizontal drilling, and subsurface-imaging techniques pioneered by the oil and gas industry for geothermal drilling, unlocking previously inac­ces­sible heat sources. (In its demon­stra­tion, the company drilled 8,000 feet down, turned sideways, and drilled 4,000 feet over.) Water pumped at high pressure through the injection well emerges into the hot surrounding rock across multiple zones and is sucked back up into a production well, which returns it to the surface to power a 3.5‑megawatt steam generator, a new record for an enhanced geothermal system, or EGS. 

Most excitingly, Fervo is on a rapid learning curve, completing each new well faster than the one before. Scaling up its generating capacity 100-fold won’t be a matter of inventing new technology, but will demand drilling 100 identical wells, with significant speed and cost savings expected along the way as the company gathers more data about the best way to drill and to tap different geothermal reservoirs. Already Fervo has broken ground on a project in Utah that will deliver 400 megawatts of power when it reaches full capacity in 2028. Fervo CEO Tim Latimer believes that EGS could eventually produce several hundred gigawatts of power, enough to cover 20 to 30 percent of U.S. electrical demand. 

There’s one more technology that could help supply clean firm power: long-term thermal storage. Last year we helped finance a Mass­a­chu­setts company called Fourth Power, founded by MIT mechanical engineering professor and heat-transfer expert Asegun Henry. The company’s pioneering technology can draw electricity from the grid during periods of peak production, transform it into heat, and store it in large graphite blocks. When the grid needs more power, the heat is turned back into electricity using ther­mopho­to­voltaic cells. The life blood of the whole system is a unique heat-circulation system using molten tin propelled by all-graphite pumps. We believe Fourth Power’s unique long-duration storage capability, coupled with the ability to return stored power as electricity, is a game-changer for the grid. 

In all of the energy projects DCVC backs, we focus on tech­nolo­gies that provide multiple advantages. They could be more versatile, powering many appli­ca­tions at once. They could be smaller or less costly, facil­i­tating faster and wider deployment. They could be located closer to where they’re needed; less likely to disrupt communities or provoke NIMBYism; or more distributed and therefore more resilient against outages and failures. ​“All these companies are dealing in different ways with climate-forcing functions and the expansion of variability on the grid, and all in comple­men­tary ways,” says Slaybaugh. ​“Which is good, because these are issues we’re going to be dealing with for a long time.”