Major Source of Energy

Major Sources of Energy

Source of energy means the materials or objects that contain energy in usable quantities. In its mutually transformable forms, energy is conventionally classified into such forms as chemical, mechanical, electrical, nuclear etc. of the great variety of natural energy sources, those used in quantity to answer practical needs are referred as "man: or " major" sources.

The major sources of energy are :

1. Fuels
2. Energy stored in water
3. Nuclear energy
4. Wind power
5. Solar Energy
6. Tidal power
7. Geothermal energy
8. Thermoelectric power

Solar Energy

Energy : Energy can be defined as the capacity of any objects to do work.

Energy Science: The study of various forms of energy and its conversion from one form to another is called energy science.

Energy Technology: The applied part of energy science useful to human beings is called the energy technology.

Solar Energy : Sun is teh fundamental source of all type of energy. The sun releases the enormous amount of energy due to continuous nuclear fusion reaction taking place in it.

Advantage of Solar Energy

1. It is available in abundance and free of cost . It is inexhaustible form of energy and will be sufficient to sustain as far as we think of our existence.
2. It is free from pollution and having low operating and maintain cost.
3. No elaborated arrangements are needed for transportation , storage or handling as in the case of fossil fuels.
4. The operation of solar thermal energy ranges from solar cookers of 1 kw to power plant of 200 MW.

Disadvantage of Solar Energy

1. Availability depends on several conditions, like weather, climate, month, time of day, and during the year.

2. Needs very large collector are to harness solar energy involving high capital cost.

3. Solar collectors, panels and cells are relatively expensive to manufacture although prices are falling rapidly.

4. Solar power are used to charged battery so that solar power devices can be used at night. However , the batteries are large and heavy and need storage space. They also need replacing from time to time.

Geothermal Energy

1. Geothermal energy supplies  more than 10,715 MW to 24 countries worldwide which is expected  to generate 67,246 GWh of electricity in 2010.
2. It is reliable sources of energy which is available continuously throughout the year and independent of weather condition.
3. India has reasonably good potential for geothermal; the potential geothermal provinces 10,600MW of power.
4. At presents there are no geothermal plants in India. There are also no installed geothermal electricity generating capacity as of now and only direct uses (e.g. Drying) have been detailed.

Wind  Energy

 Wind energy is a form of solar energy. Wind energy (wind power) describes the process by which wind is used to generate electricity. Wind turbine convert the kinetic energy in the wind into mechanical power. A generator can convert mechanical power into electricity. Mechanical power can also be utilized directly for specific task such as pumping water. 

Wind  Energy Basics

 Wind is caused by uneven heating of the atmosphere by the sun, 

 variations in the earth's surface, and rotation of the earth. Mountains, bodies of water, and vegetation all influence wind flow patterns. Wind turbine convert the energy in wind to electricity by rotating propeller-like blades around a rotor. The rotor turns the drive shaft, which turns an electric generator. Three key factors affect the amount of energy a turbine can harness from the wind: wind speed, air density, and swept area.

Equation of Wind Power

• Wind speed

The amount of energy in the wind varies with the cube of the wind speed, in other words, if the wind speed doubles, there is eight times more energy in the wind (). Small changes in wind speed have a large impact on the amount of power available in the wind 

• Density of the air

The more dense the air, the more energy received by the turbine. Air density varies with elevation and temperature. Air is less dense at higher elevations than at sea level, and warm air is less dense than cold air. All else being equal, turbines will produce more power at lower elevations and in locations with cooler average temperatures^[5].

• Swept area of the turbine

The larger the swept area (the size of the area through which the rotor spins), the more power the turbine can capture from the wind. Since swept area is , where r = radius of the rotor, a small increase in blade length results in a larger increase in the power available to the turbine