Advanced Compressed Air Energy Storage

A Unique Grid Storage Solution

How A-CAES works

A-CAES is unique as a grid storage solution: it provides long-duration storage like pumped hydro, but has the key advantage of being able to be flexibly sited where the grid needs it, allowing the targeting of high-value (and immediately available) grid applications like transmission deferral and fossil plant replacement. The technology operates very similarly to a gas plant but is entirely non-emitting, is much more cost-effective than batteries at scale with a 50+-year asset life and is ideally suited to providing the long-duration storage resource necessary for decarbonizing the grid.

A-CAES represents an important paradigm shift in “conventional” CAES technology, improving upon it through two primary innovations: a proprietary thermal management system and the use of purpose-built hard-rock air-storage caverns, enabling emission-free operation and siting flexibility.

Compress Air Using Electricity 1

Off-peak or surplus electricity from the grid or a renewable source is used to run a compressor and produces heated compressed air.

Capture Heat in Thermal Store 2

Heat is extracted from the air stream and stored inside a proprietary thermal store preserving the energy for use later in the cycle. This adiabatic process increases overall efficiency and eliminates the need for fossil fuels during operation.

Store Compressed Air 3

The compressed air is stored in a purpose-built cavern where hydrostatic compensation is used to maintain the system at a constant pressure during operation.

Convert Compressed Air to Electricity On Demand 4

Hydrostatic pressure forces air to the surface where it is recombined with the stored heat and expanded through a turbine to generate electricity on demand.