Can you classify energy sources into the renewable and non-renewable groups?

Answer 1

When you use petrol, gas, coal... basically anything you burn to produce heat and then turn this energy into electricity of mechanical energy (a car engine) you are using a raw material that is not going to be replaced. In fact petrol, gas and coal takes million of years to be naturally produced.

When you are burning wood (from trees), the tree grows again... eventually if you let it do so. This energy can be "kind of renewable" as long as another tree grows as fast in order to replace the one you cut.

Wind mills, Solar cells or Turbines in the sea take their energy from wind, solar heat, and the attraction from the moon on the sea. There are based on "natural" energy. This energy will be available as long as our planet exists.

There are a couple of sites explaining how to build home made wind mills reusing common old materials... not very efficient but cheap and allows recycling... that is "using again something that is non renewable for another purpose".

Answer 2

Yes. depending on the rate of which deforestation happens and how quickly the trees will regrow effect wether it is classified as renewable or nonrenewable.

Answer 3

Areas of commercial forests are felled in rotation for timber, and new saplings planted for future felling. Therefore, timber is a renewable resource.

Answer 4

Biomass is a renwable resouce