Learn Intext Exercise 14.3 with Free Lessons & Tips

The Energy from the oceans can be obtained mainly in three forms. These are:

1)Tidal Energy

2)Wave Energy

3)Ocean Thermal Energy

Limitations of Tidal Energy:

a)There are a very few sites around world which are suitable for building tidal dams.

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

⇒Limitations for wave energy:The Movement of ocean waves is associated with kinetic energy.Such sites in the world are limited where the waves strike the shore lines with sufficient power.

⇒Limitations of thermal energy:To Convert thermal energy into electricity, a temperature difference 20ºC (Or more) between the surface of water of ocean and deeper water is needed for operating OTEC power plants. This Involves high cost. 

Geothermal Energy. Geo' means 'earth' and 'thermal' means 'heat. Geothermal energy is the heat energy from warm rock present inside the earth. The rocks at some depth below the surface of the earth are very, very warm.This heat comes from the fission of radioactive materials which are naturally present in these rocks.

A Concave Mirror would be best suited in a solar cooker because it focuses the sunlight in avery smal  area of the solar cooker and a high temperature is produced in it which is sufficient to cook the food.