Scientists have engineered a water-soluble pyrimidone molecule that captures solar heat and releases it days or weeks later—enough to boil water on demand.
some goods and intermediates have large energy content, like, if you wanted to use energy from large pv farm in, say, morocco, then it might make more sense to ship bauxite in and aluminum bars out (it takes some 50MJ/kg to make aluminum)
simplicity of the system would be a factor in small, unattended installations like for space heating for single home
Easier, but transmission loss limits is significant.
some goods and intermediates have large energy content, like, if you wanted to use energy from large pv farm in, say, morocco, then it might make more sense to ship bauxite in and aluminum bars out (it takes some 50MJ/kg to make aluminum)
simplicity of the system would be a factor in small, unattended installations like for space heating for single home