>Grid-scale lithium batteries are being built in Australia and California. What we want is battery technology that can serve as baseload for extended period of

>Grid-scale lithium batteries are being built in Australia and California. What we want is battery technology that can serve as baseload for extended period of time when the sun isn't shinning (enough) and wind isn't blowing (enough). The battery farms being built are mainly for "frequency control and ancillary services (FCAS) market" - because they can only store enough energy, generally, for a few minutes, maybe an hour or so. That's not nearly good enough. We need power for days to offset the intermittency of wind and solar (which varies through out the day, as well as throughout the year, and throughout multiple years). >To do baseload with solar it's easy: deploy enough PV and back that with 20 hours grid scale batteries. Easy eh. So why isn't it happening? The reality is that you will not be able to deploy batteries to power even a moderate-sized city for 20 hours with current technology. It isn't going to happen in the next few decades either. Your argument has been made now for a decade or more. Maybe we need another decade so that, as a society, we can internalize the fact that isn't going to happen.