Wind, which is substantially air in motion, has kinetic energy by virtue the movement of large masses of air caused by differential heating of the atmosphere by the sun. At any given time, the amount of power contained in the wind energy is proportional to the wind speed at that instant in the context of wind energy production systems. This energy can utilize for performing mechanical and electrical works. So, let’s look at the wind energy and windmills.
Wind turbines can be used to generate electricity, for lifting water from wells, for direct water pumping and many more.
Types of Windmills
- Multiblade type windmill
- Sail type windmill
- Propeller type windmill
- Savonius type windmill
- Darrieus type windmill
Advantages of Windmills
Nonpolluting and environment-friendly source of wind energy
Important renewable and sustainable source of wind energy,
available free of cost.
Generation period is low.
Easily available in many off-shore, on-shore and remote areas
Limitations of Windmills
Low energy density
Favorable in geographic locations which are away from cities.
Variable, unsteady, irregular, intermittent, erratic and dangerous
Wind turbine design, manufacture, and installation have proved to be complex due to widely varying atmospheric conditions.
Located only in vast open areas
Continuous whirling and whistling can be irritating.
Economical only on a small scale
Geothermal energy is the energy which lies embedded within the earth’s crust. There is an increase in temperature of the earth with increasing depth below the surface.
All the heat stored in the earth’s crust and thermal energy constitutes the inexhaustible source of energy termed as geothermal energy.
Two main uses of geothermal energy are:
- Geothermal power plants are generally built where geothermal reservoirs are located within a mile or two of the surface.
- Geothermal heat pumps use stable ground or water temperatures near the earth’s surface to control building temperatures above ground.
Advantages of Geothermal Energy
- Most versatile
- Least polluting source
- Provide steady baseload power with very low variable
- And, high power generation than for solar and wind
Limitations of Geothermal energy
Overall efficiency for power production is quite low (15%) as compared to fossil fuels (35 to 4O%).
Moreover, air pollution results in case of release of gases present in steam and hot water coming out of the geothermal resource discharged into surface water bodies may be ecologically hazardous.
Thus, drilling operations at sites cause noise pollution.
Tides are formed due to the gravitational effect of the sun and moon on the earth. The gravitational force causes a periodic rise and fall of the water level of the sea in rhythm with the daily rhythm of the rising and setting of sun and moon.
So, this periodic rise and fall, called a tide, can use to produce electric power which in this case is known as tidal power.
Tidal energy has great potential in areas like the Gulf of Kutch in Gujarat, Gulf of Cambay and Sunder ban area of West Bengal where In height of the tide is sufficient for construction and economical functioning of the tidal power plant.
The tidal energy can be harnessed by constructing a tidal barrage.
Due to the high tide, the sea water flows into the reservoir of the barrage this turns the turbine to produce electricity.
Under the low tide water from the reservoir flows back into the sea and turns the turbine to generate electricity.
Biomass, defined as a living matter or its residues. It includes all the new plant growth, residues, and wastes, algae, agricultural and forest residues, wastes, biodegradable organic effluents from industries like sugar, slaughterhouse, meat packing plants, distilleries etc.
Biomass resources fall into three categories
Biomass in its traditional solid mass (wood and agricultural residue)
Furthermore, biomass in a nontraditional form (converted to liquid fuels).
To ferment the biomass anaerobically to obtain a gaseous fuel called biogas.
Sources of Biogas
- Crop residue
- Vegetable residue
- Water hyacinth
- Poultry droppings
- Ocean keep
- Cattle waste
Advantages of Biogas
Plants ensure a continuous supply of energy due to their continuous growth.
Potential for rural area
Biogas can use for cooking purpose.
For operating small engines for pumping water
And, Wastes can use as an excellent fertilizer
Limitation of Biomass energy is except biogas production, the other biomass energy sources have to be establishing a significant role.
Hydrogen Energy and Fuel Cells
One of the most important features of hydrogen energy is that it can produce from water which is available in nature. It has the highest energy content per unit mass than any chemical fuel.
So, the energy can substitute for hydrocarbons in a broad range of applications, often with increased combustion efficiency.
It is non-polluting and can use in fuel cells to produce electricity and heat.
It operates like a battery.
A fuel cell requires no recharging. It will produce energy in the form of electricity and heat.
It is an electrochemical Conservation device that converts hydrogen and oxygen into water, producing electricity and heat in the process.
Advantages of Fuel cell
Less pollution, the low noise so it is acceptable to residential areas.
Furthermore, high operating efficiency as it does not involve a thermal Process.
Thus, the unit is lighter smaller and needs less maintenance.
Limitations of Fuel cell
- Low voltage
- High initial cost
- Low service life