A pioneering $1bn project for large-scale storage of energy from wind and solar power has been launched in Utah, offering a way to manage the variability of renewable generation.  A consortium including Mitsubishi Hitachi Power Systems of Japan on Thursday announced a plan to use a huge salt cavern to store hydrogen or compressed air, which could be used to generate up to 1,000 megawatts of power.  The variable output of wind and solar power, both within a day and seasonally, is one of the principal obstacles impeding the rise of renewable energy, and cost-effective large-scale storage using hydrogen or compressed air would be a significant breakthrough for the industry.

The Utah project, known as Advanced Clean Energy Storage, is intended to serve customers on the west coast of the US and in Nevada that have growing shares of renewable power generation, storing energy when electricity prices are very low or negative, and then releasing it when supplies are tighter and prices rise. The consortium partners aim to have it in operation in 2025, with an initial output of 250MW, rising to 1,000 MW later.

Paul Browning, chief executive in the Americas for MHPS, which is a joint venture between Mitsubishi Heavy Industries and Hitachi, said the project would be the world’s largest energy storage facility designed to manage the variability of renewable power sources.

“We’re doing something that’s of foundational importance,” he said. “We’ve  still got work to do, but we’re really excited.”  The consortium is aiming to deliver power at a cost that is the same as, or lower than, the lithium-ion battery storage units that are now starting to be deployed to help manage variations in electricity supply and demand in many markets.  Those battery systems are limited to a maximum storage capacity of a few hours, however, meaning they are useful only for managing intraday variations. Storage using hydrogen or compressed air can last indefinitely, meaning that it can be used to cover seasonal downturns in wind or solar generation.

The size of the Utah cavern, which is about one mile deep and three miles across, meant the storage capacity of the site was effectively unlimited, Mr. Browning said.