Idle
the sun
The greates source of energy is the Sun
solar energy
organic matter in it
Greatest ???No - for us the greatest source is the sun, which is mostly visible light.X-rays do have more energy than visible light, but not as much as gamma rays.
It is the greatest source of energy discovered.
On Earth, the greatest source of thermal energy would be at the earth's core.
The primary energy source of mushrooms is organic matter, such as decaying plant material or wood. Mushrooms are decomposers, breaking down this organic matter to obtain energy for growth and reproduction.
The greatest amount of energy in a community is in the sun, which serves as the ultimate source of energy for most living organisms through the process of photosynthesis.
Well it depends on what type of matter your talking about here. For an example coal can be considered a matter, and from coal we get energy like burning it for electricity.
Biomass
gasoline is matter, it is burned to create energy