question_answer

   (a) State the principle of working of windmill. (b) What is the minimum wind velocity required to obtain useful energy with a windmill? (c) Give one limitation of windmill.

Answer:

                  Solar energy is used directly as heat or by converting it directly into electricity. For example, solar cooker (or solar water heater) and solar cell panels.                                         Solar energy is used indirectly by converting it into chemical energy (like bio-mass energy), harnessing the energy of wind, sea waves, tides and ocean thermal energy. For example, Bio-gas plants and windmills.