Pumped Hydro Energy Storage Is Having a Renaissance
By Chris Baraniuk, WIRED.
Excerpt: ...workers began adding a secret, light brown powder to water as they mixed up a special fluid that can store energy.... Their goal was to achieve a mixture 2.5 times denser than water. ...Pumped hydro first emerged in the late 19th century. During subsequent decades, countries including the US and UK built lots of large plants, though construction had waned by the 1990s. The tech was originally designed to complement fossil fuel power plants, making use of excess energy they produced. But today grid operators increasingly value pumped hydro plants as workhorses able to mediate highly variable wind and solar assets. They can fill in shortfalls in electricity generation or soak up surplus energy within minutes, and store it for short or long periods....