You could argue that the sun has provided all the energy for the organic materials that coal consists of. Or even the compression and heat that coal suffered from during its formation ( As a spring that becomes compressed gaining potential energy )
THE ANSWER IS fosill fuel!
The Sun.
They both burn easily with lots of heat.
Living things or plants
Since this world's fossil fuel supply is getting lower, people need to find alternative forms of energy to continue producing electricity. Since biomass is an alternative energy source, its importance is growing in place of fossil fuels.
Biomass has many benefits, the primary one being that it cannot be depleted like fossil fuels. ... With an abundance of plants on Earth, biomass could be a primary source of renewable energy that's used as a sustainable alternative to fossil fuels
In a sense it is, but only if your life-time approximates a quarter of a million years. For ephemeral humans the answer is no.
biomass
because it is
organic matter in it
Wind
the sources of biomass energy are garbage, wood, waste, landfill gases, and alcohol fuels.