Advanced Compressed
Air Energy Storage

Our patented A-CAES technology allows grid operators to draw on clean energy, even when there is no sun to fuel solar panels and no wind to generate energy from turbines

Charging A-CAES

Compress air
using electricity

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

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Capture heat in above
ground thermal storage

Heat is extracted from the air and stored in a proprietary thermal storage tank preserving for use later in the process. Saving the heat increases efficiency and eliminates the need to use fossil fuels during discharge.

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Store compressed air

The cool compressed air is then stored in a purpose-built underground rock cavern which uses a water head to use enhance land use density and maintain the system at a constant pressure.

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Convert compressed air
to electricity on demand

When energy is needed, the water head weight is released and with the help of gravity, air is pushed to the surface where it is recombined with the stored heat and expanded through a turbine to generate electricity on demand.

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Watch video to see how A-CAES works

Process flow

A-CAES benefits

  • Low installed cost per kWh for large-scale, long-duration energy storage (100+ MW)
  • 50+ year lifetime
  • Low operating costs, and increased efficiency over existing CAES systems
  • Thermal storage system uses no fossil fuels
  • A-CAES technology is 100% emission free and is a critical piece of infrastructure to transition away from GHG emitting energy sources
  • Proprietary purpose-built rock caverns allow for flexible project siting
  • No toxic material, contaminants, or thermal impacts on environment
  • Established mechanical equipment from leading suppliers is matched with seasoned engineering expertise, system warranty and delivery guarantees
  • Highly scalable system design to match client requirements, with independent settings for charge, discharge and storage capacity
  • Ability to provide incremental capacity (MWs) and duration (MWh) in the future on a cost-effective basis with limited downtime as system needs change over time
  • Synchronous motors and generators provide rotational inertia supporting existing operators know how to support grid stability
  • Full suite of ancillary services available including voltage support, spinning reserve, black start and frequency response

Technology applications

Fossil plant &
mine repurposing
Mines &
large industrial