Fossil fuels actually got their energy originally from the?

Fossil fuels originally got their energy from the sun, as they are derived from the remains of ancient plants and microorganisms that photosynthesized to convert solar energy into chemical energy. Over millions of years, these organic materials were buried under layers of sediment and subjected to heat and pressure, transforming them into coal, oil, and natural gas. Thus, the energy stored in fossil fuels is essentially ancient solar energy, captured and stored in biological matter.