Diesel Generators in Ethiopia, page-27

Well they could do like Sandfire mining (and several other miners ) have done use solar during the day and diesel generation at night (a hybrid system) so no batteries needed

The industrial solar driers for coffee do not normally use photovoltaic cells , they use water heated by the sun to then transfer heat to a drier

Edencrete nanotubes in concrete could have an advantage in transferring heat as well given they increase concrete conductivity - ie in a concrete wall behind glazing or in a trombe wall