Long-Duration Energy Storage (LDES) using the proprietary Geo2Watts Borehole Battery™ captures low-cost electricity during periods of excess renewable generation—typically midday when solar output is highest—and converts it into stored thermal energy deep underground. This energy is stored in repurposed idle hydrocarbon wells and later converted back into AC electricity using a Reversible High-Temperature Heat Pump (RHTHP) during periods of peak demand.

The value proposition for the Borehole Battery™ is especially compelling in California and Texas, where grid conditions are shaped by high penetrations of solar and wind. Solar generation peaks around midday, while electricity demand rises sharply in the early evening. This growing mismatch produces the well-known "Duck Curve", characterized by a steep ramp in demand precisely as solar production declines. The Borehole Battery™ directly addresses this challenge by shifting excess daytime renewable energy to evening hours, flattening the curve, and capturing premium electricity prices.

In addition to energy arbitrage, the Borehole Battery™ enhances grid stability and reliability. It provides a dispatchable, behind-the-meter, AC-to-AC power source that does not require inverters and, in brownfield deployments, does not require new transformers. With millisecond-scale spin-up capability, the RHTHP enables the system to provide grid stability services traditionally supplied by lithium-ion batteries—while delivering 10+ hours of storage at a lower levelized cost of storage.