Apart from the ubiquitous lithium-ion battery system, the recent solar energy storage tender in Israel has also attracted another alternative storage method: compressed air energy storage (CAES).
The first thing that comes to mind when energy storage system is mentioned is lithium-ion batteries, followed by the celebrated hydrogen fuel cell in recent years, whereas CAES has been relatively unpopular with little to no existence, though the particularly uncommon energy storage system was seen in the second round of renewable energy tender for solar energy and energy storage in Israel, and eventually became the winning bid.
The concept of CAES works by sealing renewable electricity in underground storage cans at a higher pressure, or refining on the utilization of geological and environmental conditions, where abandoned mines, sedimented energy storage cans at the bottom of the sea, salt mines, as well as expired oil and gas wells or gas storage wells, can all become energy storage spaces, where the air is released to actuate the spinning of the turbine to generate power when in need.
The efficiency of CAES is not affected by time and the increases in the cycles of charging and discharging, and the technology has a relatively long lifespan that does not require equipment replacements or upgrades every several years. CAES is an energy storage method that exerts better performance and larger storage capacity.
▲Augwind has established a pilot system at the Negev to the south of Israel. (Source：Andrew Shiva / Wikipedia)
CAES was relatively emphasized in the 33 tenders released by the Israel Electric Corporation, which comprised of 608MW solar energy and 2.4GWh of energy storage.
Israeli CAES firm Augwind announced that it has obtained an allocated storage volume of 120MWh, and will be signing a MOU with Energies Nouvelles, a subsidiary of French energy giant EDF that is set up in Israel, where the two parties will be establishing composite CAES solar power plants in the future, including a power plant comprises of 20MWh of compressed air and 5MW of solar power.
Augwind commented that the CAES equipment of Augwind achieves an overall efficiency of 75-81% for systems that start from 5MW, which although is lower than the efficiency of lithium-ion batteries, it continues to benefit in an endless loop owing to no deterioration for CAES systems.
According to the plan, the successful bidder will obtain a 23-year electricity purchase agreement and provide power at US$0.0544/kWh (ILS ₪ 0.1745), and is required to complete construction before July 2023, which helps the Israeli government in further realizing the target of increasing the ratio of renewable energy from 17% to 30% by 2030.
(Cover photo source: Augwind)