1. The 'energy can neither be created, can not be destroyed, can only be transformed. Typical energy resources include fossil fuel, biofuels nuclear fuels the sun, wind, water, geothermal energy. Fuels and energy resources can be sorted into two groups: non- renewable and renewable. Most non-renewable fuels are fossil fuels made under the Earth’ s surface. Burning the fossil fuels releases heat that turns water into steam. The steam is used to rotate the turbines that are used to generate electricity. Renewable fuels are ones that can be made as quickly as they are used up by combustion.

2. The 'Solar energy is the energy associated with solar radiation. It is from almost all other sources of energy available to man. Can be used directly for energy purposes to produce heat or electricity. There are three main technologies to transform energy into usable energy from the sun. - the solar panel: exploits the solar rays to heat a liquid that transfers heat through a heat exchanger, water. - the solar cell: produces electricity when it is requested by the light - Concentrating solar panel: uses a series of mirrors to produce heat

3. Wind energy is the energy possessed by the wind. The plants capable of capturing the energy of the wind and convert it into electricity or mechanical, are installed on the coasts or on islands, because these points the winds blow throughout the year.

4. A problem not yet solved is that of the accumulation of electrical energy, made ​​ it essential to make up for a lack of wind. More generators connected together forming the Wind - farms "and are the real power.