The Sun is about halfway through its main-sequence stage, during which nuclear fusion reactions in its core fuse hydrogen into helium. Each second, more than four million tonnes of matter are converted into energy within the Sun's core, producing neutrinos and solar radiation
The energy we capture for use in earth comes largely from sun or from nuclear forces local to our own planet. Solar radiation reaches earth with more than enough energy in a single square metre to illuminate five sixty watt lightbulb if all the sunlight could be captured and converted to electricity.☺☺