Resumen:
Nuclear fusion taking place in the sun is safe to use directly as photovoltaic (PV) and concentrated thermal energy or indirectly as wind, wave, or tide energy. Nuclear decay in the Earth’s interior is also harnessed, with Iceland setting the pace for reliable whole-country supply of geothermal energy. Conversely, nuclear fission is an ill-understood process making nuclear technologies’ failures surprisingly regular. This chapter addresses the sustainability of the foregoing types of radiation energy sources. It first highlights the supply of incident solar energy that can power the geosphere and biosphere and cater to the needs of a thriving future human civilization. Second, the technological conditions for sustainable geothermal energy (SGE) are examined. Third, while discounting weak antinuclear arguments (public perceptions), it shows the absence of technical conditions for sustainable fission nuclear power.