Pumped Hydro Energy Storage

From a reader:

Connecticut’s largest lake (Candlewood Lake) is really a 100-year-old hydroelectric facility. Water is pumped from the Housatonic River through a gigantic tube and into the lake, where the water is stored until it’s needed to generate electricity. Then, the water is released through the same pipe, cascading 230 feet downhill (Niagara Falls is 188 feet), powering two generators based under the brick Rocky River Hydro Generating Station. When it opened in the 1920s, it was the first time that humans had pumped so much water up such a high elevation. The 11-mile-long lake stretches from **Danbury ** to Sherman. Hear the unbelievable story behind the building of the lake on the next episode of Amazing Tales from Off and On Connecticut’s Beaten Path.

Thanks for this.  Pumped hydro represents more than 95% of the energy storage we have online at this moment, though it will gradually give way to batteries.