Hydroelectric Damming of rivers and utilizing the potential energy store in the water. Eventually the stored water is released under pressure whereby it turns turbine blades generating electricity.

Hydroelectric Create water reserves as well as energy supplies. Advantages Disadvantages Create water reserves as well as energy supplies. Costly to build. Can cause flooding Dams have major ecological impact on local water systems.

Tidal Using the natural motion of the tides to fill reservoirs, where are then slowly discharged through electricity producing turbines.

Tidal Construction of barrage is costly. May reduce tidal flow. Advantages Disadvantages Ideal for island such as the UK. Potential to generate a lot of energy. Tidal barrage can double as a bridge, and help prevent flooding. Construction of barrage is costly. May reduce tidal flow. May have a negative impact on wildlife.

Biomass Decaying plant or animal waste. An organic material, which can be burned to provide energy.

Biomass Cheap and readily available source of energy Advantages Disadvantages Cheap and readily available source of energy If replaced, can be long term, sustainable source of energy. When burned it gives off pollutants, including greenhouse gases. Only renewable if crops resource are replanted.