Biomass

Terrestrial plants are those that grow on land and the aquatic plants grow in water.Biomass is the organic matter produced by plants, both terrestrial and aquatic and their derivatives. It includes forest crops and residues, crops grown for various purposes and animal manure.
Biomass is basically organic, carbon based, material that reacts with oxygen in air during combustion and natural metabolic process to release heat. Such heat at higher temperature can be conveniently be used to generate work and electricity.
Unlike the fossil fuels like coal,oil and natural gas which take millions of years to form, biomass form within a short time period and their formation do not cease as long as life remains. Thus it can be considered as Renewable Energy source.
Indirectly Biomass can be considered as a form of solar energy,as the plants use solar energy to grow themselves by a process known as photosynthesis.
Biomass sources of energy fall into three categories namely raw Biomass, Biofuels and Bio gas.
Biomass is the traditional solid mass, which is generally characterized by wood and agriculture residue. It is burnt down to provide heat for cooking and other purposes.The most traditional use of biomass combustion includes cooking with firewood. The extent and the amount of usage in this way is difficult to assess but its believed about 10-20% of global energy usage is made by this way. Industrially also the use of Biomass has been done since years like in the sugarcane milling, tea drying, brick drying. The usage as such is made for heat and power. But the efficiency of such usage is generally found low. Based on this it can be easily said that the biomass energy is used globally under the following main heads.
1. Domestic cooking and heating.
2.Process heat and electricity.

Wind Energy

Wind carries enormous amount of energy with it. Generally the pressure that we feel across us as we walk or move is known as wind power.The following main factors cause winds.
1.The convection air currents caused by the heating and cooling of the atmosphere. The heating of earth's surface is caused by the solar energy.
2.The rotation and revolution of the earth.
 The potential of wind energy as a source of power is large and the resultant energy is renewable in nature.
Basically the the conversion of wind energy into electrical energy is performed by the use of wind turbines characterized by long blades. The turbine is coupled with a generator shaft which produces electricity.

Tidal Energy

We know what tides are. The periodic waves of water that rise and fall in the sea water are generally named as tides.The tides in the sea are the result of the universal gravitational effect of the heavenly bodies like the sun, moon etc that are around the earth. The gravitational pull becomes apparent in the motion of the water as a result of the fluidity of the water mass. The periodic rise and fall of water in the sea occur with the rising and setting of the sun and moon. Tides do have some recreational advantage. People generally enjoy spending their time along the sea shore looking at the rhythmic tides. It is believed that the tea teaches the people to be violent yet tolerant, huge yet humble and rapid yet quite.
Now it is even fascinating to know that the high tides in the sea can be used to harness electrical power, since the tides carry huge energy with them and  and it is known as Tidal Energy. Also, since the gravitational effect of the heavenly bodies will remain forever, the Tidal Energy is a Renewable Energy source.
But the energy harnessing is not easy. It is not possible every where as well.It is possible practically in certain and specific geographical locations.
Generally the method is carried on by the construction of a dam across the tidal path giving rise to a tidal basin. During high tides the sea water flows into the basin and during low tide the water flows into the sea from the basin. In both these cases the flow occurs through the dam, where a hydro turbine is placed which drives a generator, which produces electricity.
In concern with the present energy crisis tidal energy has wider future prospects.

Geothermal Energy

Geothermal energy is the energy is the energy which lies embedded within the earth.It is believed that the earth has a molten core.Temperature gradience exists as we move deeper the earth surface.The fact that volcanic eruption takes place in various parts of the earth prove that belief. This heat inside the earth is used as a source of energy and is known as Geothermal Energy.
Since the molten core of the earth will never cool down, this energy source is considered to be renewable.
In some cases the steam and hot water inside the earth comes naturally to the surface in some locations of the earth. Such locations are known as hot spots.The hot steam is used to drive turbine which generates electricity. Similarly the heat can also be used in other heating and lighting applications. Generally such usage is for small scale energy production. For large scale production bore holes are sunk inside the earth surface as deep as 1000 meters, releasing steam and water at higher temperature and pressure.
Present Geothermal energy usage rate is not significantly high, but it is expected to rise with the global energy crises due to the shortage of fossil fuel.The usage of such energy sources is expected to go up in different parts of the world in the coming years.

Introduction to Energy

Energy is the vital part of everyday life.Each of our day to day action require energy in one for or the other.To stress the importance of energy, we can simply mark that the world would not exist without energy.

Our planet earth carries energy in two principle forms, namely :Renewable Energy and Non-Renewable Energy.This classification is made on the after effects of energy usage.

The energy sources which cease away with time and their usage are categorized as Non-Renewable Energy sources. These are also known as finite supplies. Fossil fuel is the most illustrative example of non renewable energy, as they have limited supplies.

On the other hand Renewable Energy Sources are the finite supplies. They do not cease away with time. Solar Energy, Hydro power, etc are some of the examples of Renewable Energy.  

Solar Energy Collectors.

Harnessing the Solar Energy Into usable artificial forms is not a easy task. Different types and shapes of energy collectors are used to collect the energy from the sun.

c.Light Energy

The Sun lights of the planet in the day time. during the night hours solar energy can be used for artificial lighting purposes also. This can be done by converting the solar Energy into Electrical Energy and then back to Light energy.

b.Heat Energy

The sun is the constant supplier of Heat Energy to the Earth. The maintenance of the optimum temperature in this planet is due to the sun. The heat of the sun can also be used in artificial heating purposes these days like the heating of water .

Photosynthesis

The basic use of solar energy  is made by the green plants in the process of photosynthesis. By this process the plants prepare food which is consumed by every other living being. Photosynthesis is the chemical process performed by plants in the presence of oxygen, mineral salts and the absorption of Solar Energy.

Solar Energy

The sun is the pioneer and principle source of every form of Energy available to us. In short its mandatory to say that the sun drives the planet Earth. Its incessant , constant and virtually unceasing energy source.

Types

Basically renewable energy sources can be classified into the following types:
1.Solar Energy
2.Hydro power
3.Tidal Energy
4.Wind Energy
5.Biomass, etc..

Importance

Owing to the present energy crises ,Renewable Energy sources are of great importance.Its basically due to the infinity of their supplies.