> Unfortunately, energy storage is still an unsolved problem. Mechanical, lithium based, flow, heat, compressed air, pumped hydro are all types of batteries th

> Unfortunately, energy storage is still an unsolved problem. Mechanical, lithium based, flow, heat, compressed air, pumped hydro are all types of batteries that are able to store quite large amounts of power today or in the near future. Certainly cheaper than fusion has any hope to be within 20 years.