Compressed Air Energy Storage Market

Compressed air energy storage (CAES) is a way to store energy generated at one time for use at another time. At utility scale, energy generated during periods of low energy demand (off-peak) can be released to meet higher demand (peak load) periods. In a CAES plant, ambient air or another gas is compressed and stored under pressure in an underground cavern or container. When electricity is required, the pressurized air is heated and expanded in an expansion turbine driving a generator for power production. The compressed air energy storage market is segmented based on type and geography.

The special thing about compressed air storage is that the air heats up strongly when being compressed from atmospheric pressure to a storage pressure. The heat of compression therefore is extracted during the compression process or removed by an intermediate cooler. The loss of this heat energy then has been compensated for during the expansion turbine power generation phase by heating the high-pressure air in combustors using natural gas fuel, or alternatively using the heat of a combustion gas turbine exhaust in a recuperator to heat the incoming air before the expansion cycle. Alternatively, the heat of compression can be thermally stored before entering the cavern and used for adiabatic expansion extracting heat from the thermal storage system.

The global compressed air energy storage (CAES) market is driven by implementing onshore and offshore renewable energy sources (MW-GW) demonstrating projects. These, coupled with technological developments in the compressed air energy storage systems (adiabatic systems), are expected to drive the market. Compressed air energy storage (CAES) technology can play an important role in meeting market demand for electricity, addressing the need for intermediate and peaking power generation, where natural gas-fired turbines are most suitable. CAES technology uses low-cost, off-peak power to pressurize and store air that can later be expanded through a gas turbine during on-peak periods.

The Compressed air energy storage market based on types is segmented into Adiabatic, Diabatic and Isothermal. A Diabatic Compressed Air Energy Storage (D-CAES) System is an energy storage system based on the compression of air and storage in geological underground voids (typically salt caverns, however other mediums are under development such as depleted gas fields, aquifers, and hard rock). The adiabatic approach which preserves the heat of the compression step and utilizes it in the expansion step thus it has more efficiency as compared to diabatic compressed air energy storage. In the isothermal compressed air energy storage, systems achieve a perfect or near-perfect heat exchange with the surrounding environment, but yet, have not been in practice for large scale CAES systems, as a certain degree of heat loss is unavoidable.

The Compressed air energy storage market by technology can be segmented into constant volume storage and constant pressure storage. In a constant volume storage system, specific physical boundaries control the volume of the storage space, but the air pressure of the space is variable. These systems need to maintain certain maximum pressure thresholds to avoid damage to the storage vessels. A constant pressure storage system maintains constant air pressure, while the volume of the storage is variable. These systems generally utilize huge bags for the air to be stored in and are placed deep in the ocean, to make use of the ocean’s hydrostatic pressure. The constant air pressure allows for greater efficiency of the turbines and the power plant itself. These systems are more costly due to the placement of the storage units, but they also open possible locations for CAES systems.

The compressed air energy storage market based on the region can be segregated into North America, Europe, Asia Pacific, Middle East & Africa, and Latin America. Compressed air energy storage (CAES) may become an interesting solution for countries with weak interconnection with their neighbors. North America and sub-Saharan Africa were found to have the largest portion of suitable areas for this kind of storage technology, and Western Canada in particular, to have the world’s strongest potential. The Asia pacific region and Europe is going to be prominent region for the compressed air energy storage market due high demand for intermittent renewable technologies and the need to store renewable energy for further use.

A few of the major players operating in the tidal power market include Siemens Energy (Germany), General Compression (US), Hydrostor Inc (Canada), Bright Energy Storage Technologies (US), Pacific Gas and Electric Company (US), and Apex Compressed Air Energy Storage, LLC (US)