Hydrostor

Unlike pumped hydro energy storage (PHES), progressed compressed air energy storage is fairly easy to site and construct, requiring far less space as well as water.

Worldwide investments in clean energy projects have hit a six-year low. Global spending totaled $117.6 billion in the first half of 2019, down 14% from a year earlier and the least since 2013, according to a report by BloombergNEF. Investments slowed in all three major markets -- the U.S., Europe and China -- but China’s decline was especially pronounced as the country continued its shift away from subsidies for solar and wind power.