Hot Sand – Watts Up With That?
· First, it is very cheap. Instead of using expensive lithium for storage, it uses cheap silica sand. This brings the cost down from the 327 per kilowatthour (kWh) of lithium batteries to an NREL estimated cost of 2 – 4 per kWh. And even if the final cost is three times that, it's still only a few percent of lithium battery cost.