Noon Energy

Noon Energy was founded in 2018 in Palo Alto, California by Chris Graves, who serves as co-founder and CEO. Graves, a chemist and materials scientist, had been working at Columbia University and the Technical University of Denmark on CO₂-to-fuels electrolysis technology. He was also part of the NASA team that developed MOXIE — the Mars Oxygen In-Situ Resource Utilization Experiment aboard the Perseverance rover — which sucks carbon dioxide from the Martian atmosphere and splits it into oxygen and carbon monoxide. During that work, Graves realized the same fundamental chemistry could be reversed and redesigned to make a battery. By splitting CO₂ into solid carbon and oxygen during charging, then recombining them during discharge in a reversible solid oxide fuel cell (SOFC), electricity could be stored in ultra-cheap, earth-abundant materials at unprecedented energy density.

Noon was founded specifically to bridge the multi-day energy storage gap that lithium-ion cannot economically serve. The company's published mission is to enable 100% renewable energy grids by storing electricity cheaply and reliably for 100 hours or more. Noon’s approach has three components: a power block (a reversible SOFC ceramic fuel cell) that charges and discharges the system; a charge tank that converts electricity into solid carbon while releasing oxygen to the air; and a discharge tank that draws oxygen from air to oxidize carbon back to CO₂, generating electricity. The key physics advantage is that Noon’s solid carbon storage medium is 3 times more energy-dense than lithium-ion, meaning the same energy in a much smaller space — making the system 20 to 200 times more compact than flow batteries or pumped hydro for the same capacity.

Noon Energy has raised $31 million in total, including a $28 million Series A in January 2022 led by Clean Energy Ventures and Aramco Ventures’ Sustainability Fund, with participation from Emerson Collective and At One Ventures. Founder Graves previously received support from the Prime Impact Fund and Dick Swanson (founder of SunPower) at the seed stage. The company has also received support from the California Energy Commission.

In January 2026, Noon announced the successful commissioning and multi-month operation of its first fully containerized demonstration system, which operated for thousands of hours with over 200 hours of discharge capacity in some tests — described as the first fully containerized, modular ultra-long-duration storage system at this scale to achieve sustained field operation. Noon has stated it is building a larger commercial-scale system and is in conversations with hyperscaler data center operators and utilities as its primary commercial targets.

Early-stage. Key investors: Prelude Ventures, Tishman Speyer. Developing carbon-oxygen battery technology for multi-day grid-scale energy storage.