Loved writing this piece for #DesignSpark about two Welsh valleys and the use of hydro power! Some history with waterwheel and line shafts from national slate museum then to the huge Dinorwic Pumped Storage power station then the brilliant #Commnunity owned Ynni Ogwen Hydroelectric scheme! Check it out here (email signup reqd)
https://www.rs-online.com/designspark/content-types/article/27736?lang=en