Re-Imagining Long Duration Energy Storage

Geological Energy Storage

What is Geological Storage?

Geological Energy Storage is the process of using subsurface caverns such as, salt domes, saline aquifers, or idle O&G wells to store energy in different forms - this could be air, heat, hydrogen, or something else yet to be uncovered.

There are over 3 Million idle O&G wells in the United States. Rather than abandoning these wells, operators are now able to repurpose their stranded assets into energy storage facilities. THEMES believes that we can develop GW's of energy storage throughout the United States by connecting operators and land owners with innovative technologies.

Many energy storage technologies are limited by the capital cost of their storage vessels - Geological Storage allows for a near zero marginal cost of storage; at scale, utilizing the subsurface can cut costs by 10-100x.

Adiabatic Compressed Air Energy Storage (CAES)

THEMES has developed an Adiabatic CAES system which utilizes proven surface technology paired with innovative subsurface storage in the saline aquifer zone, accessed via idle oil & gas infrastructure.

THEMES is working with a coalition of partners including University of Southern California, national labs, large O&G operators, and the largest EPC's in the world to demonstrate the initial 5MW project.

THEMES has a current projected LCOS of $0.12/kWh and following a successful demonstration, a pipeline of GW's of projects with a market leading LCOS and a path to $0.05/kWh

THEMES is developing an Isothermal CAES solution which will be deployed in the Middle East. Isothermal CAES involves using liquid sprays during the compression and expansion phases to minimize temperature change. The isothermal aspect removes the need for a heat store, which is required in A-CAES, and can allow for storage durations of 100 - 1,000 hours.

Isothermal CAES

Compressed Natural Gas

THEMES is working with NREL to demonstrate using compressed natural gas for seasonal energy storage. The process involves using excess renewables to compress natural gas from the sales pipeline. When power is needed, gas can be brought up and expanded through an expansion turbine before re-entering the sales line.

THEMES is working to develop an initial demonstration and is in search of operators interested in energy storage.