Alex

I can kinda see where the vacuum and (lack of) gravity might help with crystal growth but how do you then return something that sensitive back to earth?

My UK rates are about £0.26/kWh for the day rate, £0.07/kWh for the night rate which is when things like car charging is done. Excess solar generation makes me £0.15/kWh I send back to the grid although not much of that going on in the winter ;-)

We also pay a daily standing charge for the grid connection.