Benchmark 8C
The Designed World: Energy Sources and Use
Grades 3-5, page 193

The sun is the main source of energy for people and they use it in various ways. The energy in fossil fuels such as oil and coal comes from the sun indirectly, because the fuels come from plants that grew long ago.

NSES Content Standard B 
Physical Science: Transfer of energy
Grades 5-8, page 155
The sun is a major source of energy for changes on the earth's surface. The sun loses energy by emitting light. A tiny fraction of that light reaches the earth, transferring energy from the sun to the earth. The sun's energy arrives as light with a range of wavelengths, consisting of visible light, infrared, and ultraviolet radiation.