[mikewarot]

The grid isn't optimized for it, and the base generation is highly incompatible with the fluctuations wind and solar create. There are very real costs to rapidly cycling power demands on steam turbine driven generators, regardless of what fuel is used to generate the steam. Each heat/cool cycle causes microfractures in the shafts to grow just a bit, and those have to be bored out periodically to remove the cracks, and there is only so much metal that can be safely removed.

So, storage is an issue. If no storage/grid tie is possible, utilizing the full output of the panels to heat or cool a mass for night/cloudy days could be helpful in a home situation.

[lancewiggs]

See MGA Thermal for a way to store heat at high density and temperatures that can take steam to drive gas/coal turbines.

https://www.mgathermalstorage.com