Toshiba, Marubeni launch rock-based thermal energy storage tech pilot

Japan’s Toshiba and Marubeni, along with Japanese utility Chubu Electric Power, have deployed a pilot rock-based storage facility at Toshiba’s facility in Yokohama, Japan.

The pilot system has a storage capacity of 100 kWh and can use storage materials such as crushed stone, bricks, molten salt, concrete, and ceramics. Toshiba said the pilot facility has a relatively high heat storage density. It claims it can store heat at temperatures above 700 C, with a relatively small heat storage tank.

The next step in the project is to build a larger facility with a capacity of 500 kWh. The group aims to eventually launch commercial projects.

“Rock heat storage technology is expected to be superior to lithium-ion batteries and hydrogen in terms of environmental friendliness and economic efficiency,” said Toshiba.

The Japanese Ministry of the Environment is supporting the project under a tender mechanism designed to facilitate the development of rock-based thermal energy storage facilities in Japan.