Prometheus Ultra Long Duration Energy Storage

PROMETHEUS ENABLES ULTRA LONG DURATION ENERGY STORAGE FOR SEASONAL FIRMING AND SHAPING OF RENEWABLE ENERGY AT 1000+ HOURS

Prometheus has developed a new ultra long duration energy storage capability for firming and shaping renewable energy across seasonal variations in availability. Using its proprietary technology for converting carbonate and electricity into hydrocarbon fuels, Prometheus can store thousands of hours of energy from intermittent renewable sources, making that energy available again for firm, dispatchable delivery when needed, for weeks or months at a time.

When the fuels are used to generate power, the carbon and water from these fuels is recaptured and stored as carbonate salts in water. When renewables become abundant again (winter wind, summer sun, spring hydro, for example) the electricity is used to convert the carbonate and water back into fuel. Much as lithium or iron batteries store and discharge electricity by changing the oxidation state of their metals, Prometheus stores and discharges electricity by changing the oxidation state of carbon. While the principle is similar, the reduced (energy stored) state of carbon is in the form of liquid fuels that can be stored cheaply in large volumes, allowing for thousands of hours of energy to be stored for less than $5 / kWh, a much lower cost of storage than alternative long duration energy storage methods.

FAST TO DEPLOY

Prometheus ultra long duration energy storage (ULDES) systems can be deployed quickly, with over 75% of the capital cost of the systems consisting of conventional equipment that can be obtained in short time frames. The systems can be deployed as off-grid when needed allowing for independent power production and storage.

TRL 9 – READY FOR SCALE

Our tech is fully developed and ready to deploy at scale. We have demonstrated a pilot plant with full commercial-scale components running on off-grid solar for over a year.

MANUFACTURING CAPABILITY IN PLACE

Prometheus operates a 20,000 ft2 manufacturing facility that is capable of producing at the scale of a first commercial deployment.

NO GRID REQUIRED

Because we purpose-built our tech stack for intermittent operation, we don’t need a grid. We run when the sun shines and wind blows and idle when power isn’t available. Our low capex and electrical-only power needs mean our fuels are designed for flexible fast on-off operation.

FIRM 24/7 POWER

Prometheus fuels generate power using conventional generators, with high reliability, peaking and baseload capability. When grid connected, our systems offer spinning reserves and inertia that high reliability requires.

100% CARBON NEUTRAL

When the Prometheus ULDES systems are charged with renewable energy, the energy returned is 100% renewable as well.

INDEPENDENTLY SCALABLE POWER AND STORAGE

The power rating and energy storage capacity are independent capabilities in Prometheus ULDES systems. The power generation is chosen by the size of the generators that turn fuel to power, and the energy storage is chosen by the size of the fuel tanks.

NO TO ULTRA LOW EMISSIONS

Carbon and water from the power generation phase are captured, as are any particulates. Because the fuels are so clean, no emissions are produced, other than 1-2 ppm NOX, designated “Ultra Low Emissions” by the EPA.

PROMETHEUS ULDES SYSTEMS GENERATE REVENUE

When ULDES systems are grid connected, they can generate revenue. Energy arbitrage can be a significant source of revenue as energy pricing on grids can be negative (you get paid to take power) for 1000+ hours a year in some markets. When renewables are not available, energy prices can be much higher generating revenue when dispatching stored power. Other revenue streams include demand response, capacity fees, and tax credits, depending on configuration and markets.

RENEWABLES CAN BE 24/7/365 FOR THE FIRST TIME

With the ability to store thousands of GWH of energy and generate power at any rating conventional generators can achieve, a unique new capability is introduced for the first time – data centers and grids that can operate using 100% renewables. No more “fossil fuel backup” required.

ABOUT

Prometheus is the global leader in low-cost liquid fuels made from electricity to power AI data centers, factories, ships, vehicles, and aircraft. Prometheus offers ultra long duration energy storage for seasonal firming and shaping of renewable power, transforming intermittent renewable energy into firm dispatchable 24/7 power, anywhere it is needed. Backed by top-tier investors including Maersk, BMW, and Y Combinator, Prometheus is redefining the future of energy.

CONTACT

Email: info@prometheusfuels.com

© Prometheus Fuels 2025