a combination or alloy of these black paint or similar materials used in solar ovens solar camping showers or solar rooftop water heaters the heat storage medium 905 contains a large volume of a material with a high heat capacity this material could be water which has a volumetric heat capacity of 4 2 joules cm 3 u00b0 c or could be scrap iron which has a heat capacity slightly less than water the selective surface 904 and the heat storage medium 905 are in good thermal contact this contact possibly employs a thermal interface material 906 there between that has high thermal conductivity the ability to mate the surfaces and the ability to spread the heat the heat storage medium 905 is thermally connected to the hot side of a distributed thermoelectric panel 902 again possibly employing a thermal interface material 906 the distributed thermoelectric panel 902 is an insulating panel with thermoelectric elements inside as described in fig2 a 2 b and fig3 a 3 d the cold side of the thermoelectric panel 902 is thermally connected to ground 901 or floating on a body of water such as an ocean lake or pool without limitation the power generator illustrated in fig9 could generate power only when the sun.