Tidal energy is a form of hydro-power that converts the energy of the tides into electricity or other useful forms of power. The tide is created by the gravitational effect of the sun and the moon on the earth causing cyclical movement of the seas. Tidal energy is therefore an entirely predictable form of renewable energy, which can be harnessed in two forms: Tidal Range and Tidal Stream
Solar Energy is energy from the sun that is converted into thermal or electrical energy . Solar energy is the cleanest and most abundant renewable energy source available, and the U.S. has some of the richest solar resources in the world.
Wave Energy is the transport of energy by wind waves , and the capture of that energy to do useful work – for example, electricity generation, water desalination, or the pumping of water (into reservoirs). A machine able to exploit wave power is generally known as a wave energy converter (WEC).
Rain energy is a fairly new method for generating energy. Also see;