Alternative energy is an umbrella term that refers to any source of usable energy intended to replace fossil fuel sources without the undesired consequences of the replaced fuels. The planet Earth has always had an energy crisis. During the 1990s, the use of solar panels and nuclear fuels satisfy the energy stricken people. None of Earth's hydrocarbon (oil) energy resources could provide the resources that the power plants needed, and were later faded out as an energy fuels. The biggest example of alternative energy taking over the market when petroleum power cars sales dropped in favor of bio-fuels and hydrogen powered cars in the late 2000s.
- Solar energy is the generation of electricity from the sun. It is split up into two types, thermal and electric energy. These two subgroups mean that they heat up homes and generate electricity respectively.
- Wind energy is the generation of electricity from the wind.
- Geothermal energy is using hot water or steam from the Earth’s interior for heating buildings or electricity generation.
- Bio-fuel and ethanol are plant-derived substitutes of gasoline for powering vehicles.
- Nuclear binding energy uses nuclear fission to create energy.
- Hydrogen is used as clean fuel for spaceships, and some cars.