What are the limitations of extracting energy from

solution:

(a) Limitations of Wind Energy

(1) The wind is very unpredictable, destructive source of energy.

(2) It is not steady and consistent at all places. Thus, it can be used at the places where it is available, with consistent and steady characteristics. Wind energy farms can be established only at those places where wind blows for the greater part of a year.

(3) Establishment of wind energy farms requires large area of land. For a 1 MW generator, the farm needs about 2 hectares of land.

(4) It is not available all the time. There should be some back-up facilities (like storage cells) to take care of the energy needs during a period when there is no wind.

(5) Wind mill structures are very big whereas their outputs are very low. The initial cost of establishment of the farm is quite high. Thus, it is expensive to use wind energy.

(6) Since the tower and blades are exposed to the vagaries of nature like rain, Sun, storm and cyclone, they need a high level of maintenance

(b) Limitations of Waves Energy

Power output of such plants is variable. Also, such plants require large maintenance as equipments used in them withstand severe stresses in storms.

(c) Limitations of Tidal Energy

(1) The rise and fall of water during tides is not high enough to generate electricity on a large scale.

(2) There are very few sites that are suitable to build dams.

(3) A continuous output of electric power can not be obtained by using tidal energy.

(4) The cost of installation of a tidal energy power plant is extremely high. But the efficiencies of such plants are quite low.