Israel-based underground compressed-air storage specialist Augwind has finalized the construction of its first compressed air storage system for commercial application.

The 250 kW/1 MWh AirBattery system will be connected to a PV system located nearby and will be used for behind-the-meter services by the collective community of Yahel, in the southern, desert part of Israel.

“As part of the test run operations, all system components were activated independently and in sequence, a number of charge and discharge cycles were performed, culminating in electricity generation,” Augwind CEO Or Yogev told pv magazine. “This is the first time since the feasibility study at Yakum that the AirBattery system is being tested on a commercial scale of 1 megawatt-hour, this is a significant milestone for Augwind in its technological roadmap, ahead of the construction of high-voltage commercial projects in the future.”

The system works according to the same principles of Augwind's large scale projects. It is based on two compression inflatable polymer tanks that are placed in the ground close to each other, in addition to a series of storage tanks. The tanks are covered by steel frames, which create a sort of cage around them, and these are then placed in holes at a depth of 4m.

Renewable energy is used to power standard water pumps, which inject water into the compression tanks. The tanks are sealed, so the air they contain starts to be compressed up to the top and then shifts to the storage tanks. With on-demand energy, the compressed air is released from the storage tanks to drive a powerful water turbine which is used to generate electricity.