Limitations of energy that can be harnessed from the sea:
1. There are very few sites around the world which are suitable for building tidal barrage for harnessing tidal energy. Moreover, the rise and fall of sea-water during high and low tides is not enough to generate electricity on a large scale.
2. The harnessing of sea-waves energy is a viable proposition only at those places where seawaves are very strong.
3. Though the energy potential from the sea is very large but its large scale exploitation is difficult at the moment.