I first heard about pumped hydro back in 2007. https://www.google.com/amp/s/grist.org/article/monbiot-we-can-provide-all-or-most-of-our-electricity-from-renewa

I first heard about pumped hydro back in 2007. https://www.google.com/amp/s/grist.org/article/monbiot-we-can-provide-all-or-most-of-our-electricity-from-renewable-source/amp/ https://www.google.com/amp/s/grist.org/article/monbiot-we-ca... https://books.google.com/books?id=vsPYv7jm-34C https://books.google.com/books?id=vsPYv7jm-34C