A multi-mode solar power generation system can include a first energy conversion system that generates electricity from a working fluid heated by a portion of solar radiation focused by a plurality of heliostats. The multi-mode solar power generation system can also include a second energy conversion system that generates electricity from an unused portion of the focused solar radiation using a different energy conversion mode than that of the first energy conversion system. The second energy conversion system can include one or more photovoltaic converters, which directly convert solar radiation to electricity. The unused radiation from the first energy conversion system can include radiation spillage or dumped radiation from a thermal receiver of the first energy conversion system.