Yes, and since the water gets behind the dams via rainfall which requires the sun to vaporize water and lift it to the clouds, hydro is solar also. Likewise with wind energy (the winds are driven by solar) and by wave energy (driven by wind and in-turn driven by solar.) Meanwhile the folks being supplied with geothermal energy are getting that from nuclear - the radioactive decay of uranium and thorium in the Earth's mantle is what produces the heat. When Mt. St. Helen's blew her top more radioactivity from radon (a radioactive decay product of uranium) was released than from both A- bombs used on Japan during WWII.