Within this economically managed part of the energy sector, renewable energy sources currently provide about 25% of the energy supplied.
A large part of this renewable energy is in the form of biomass energy, either in food crops or in managed forestry providing wood for industrial purposes or for incineration1.
There are two ways to harness solar energy. Passive systems are structures whose design, placement, or materials optimize the use of heat or light directly from the sun.
