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Grid Scale Capacity

Hydrostor’s A-CAES projects are 500 MW, large enough to provide 8 or more hours of back-up power

Flexible and Adaptable

Long duration storage helps the grid adjust to variable supply and demand, all from a compact, flexibly sited facility

Mature Technology

Next-generation compressed air solution leverages established supply chains and skilled labor markets

Dedicated Professionals

Our experienced team of energy professionals are building and operating projects all around the world

Long Duration Energy Storage Systems for the Modern Grid

We use a simple combination of air, water, and underground caverns to store energy

Advanced Compressed Air Energy Storage (A-CAES) is an innovative approach to energy storage that builds on proven technology.

Project Features

500 MW or 8+ hours of energy storage on a compact footprint

No critical minerals or hazardous materials

Facilities with a 50+ year lifetime, ensuring long-term reliability

Flexible siting using purpose-built hard rock caverns – no need for salt caverns

The Advanced Compressed Air Energy Storage Process

A-CAES plants are designed to store off-peak or surplus electricity and via an efficient, closed loop system. There are five key steps: compression, heat exchange, air storage, water displacement, and discharge.

Our Technology

The Benefits of A-CAES

Reliable performance

Matches the reliability of thermal power plants, but with an emissions-free process.

Flexible siting

Purpose-built hard-rock caverns can be built where the grid needs support most, unlike traditional CAES or pumped hydro.

Essential grid services

Rotational inertia from spinning motors keeps the grid stable. Other ancillary services include voltage support, spinning reserve, black start, and frequency response.

Cost-effective with a long life

Low installed costs per kWh over a facility’s 50+ year lifespan.

Significant economic benefits

Creates high-quality jobs for skilled trades, enforcing regional infrastructure and boosting local industry.

Customized, adaptable system design

Scalable system is designed to match grid requirements. Incremental capacity and duration increases can be added in the future with limited downtime and low marginal cost.

Reliable performance

Matches the reliability of thermal power plants, but with an emissions-free process.

Cost-effective with a long life

Low installed costs per kWh over a facility’s 50+ year lifespan.

Flexible siting

Purpose-built hard-rock caverns can be built where the grid needs support most, unlike traditional CAES or pumped hydro.

Significant economic benefits

Creates high-quality jobs for skilled trades, enforcing regional infrastructure and boosting local industry.

Essential grid services

Rotational inertia from spinning motors keeps the grid stable. Other ancillary services include voltage support, spinning reserve, black start, and frequency response.

Customized, adaptable system design

Scalable system is designed to match grid requirements. Incremental capacity and duration increases can be added in the future with limited downtime and low marginal cost.