This article describes the different types of “green energy” that are currently being used as alternative sources of power.
1. Hydropower
2. Geothermal
3. Biomass
4. Wind
5. Solar
Hydro Power
Hydro Power converts energy stored in water to mechanical. Potential energy stored in water is converted in electrical using turbines. Water is stored in large quantity in dams; spillways are installed to control flow of water to turbines. Fast flowing water spins wings of turbine and energy transformation takes place.
Geothermal
Geothermal energy is harvested by tapping heat produced by earth. Geothermal energy is available all over the earth but it is very expansive to put it to work. At place geothermal energy is closer to surface of earth. At these points naturally produced steam or hot water can be tapped easily. Steam or heat is used to spin turbine and electricity is produced. Such natural points exist in US, Philippines , Italy and Pakistan California
Wind
Wind can be used to produce energy by turning large fan like blades around a hub. Wings turn at slow but steady rate at high torque. Slow rotation is converted to high rotation using gears. Gear box is attached to generator produces electricity. Modern wind turbines can produce 600KW-5 MW. Wind turbines are suitable for areas with high wind resources.
Biomass
Biomass is also considered as renewable energy because concentrated energy comes from sun. Energy capturing process is called photosynthesis. This form of energy is not completely green energy because when plants are burned to release energy they produce pollution as well.
Solar
Energy from the sun put to work in any form is solar energy. Solar energy can be used to heat up water for commercial and residential use. Solar energy can be converted into electrical energy. Photovoltaic cells can absorb light from sun excite electron to create a flow of current. Commercially available PVs are still expansive and cannot work when sun is down. Another way to capture solar energy is to concentrate it using mirrors at a boiler unit, produce steam to run turbine. This method needs sun tracker system to focus sunlight at one point.
