The most common type of hydroelectric power plant uses a dam on a river to store water in a reservoir. Water released from the reservoir flows through a turbine, spinning it, which in turn activates a generator to produce electricity…this can be seen in the following diagram.
Dams and unsightly pylons in highland valleys cause visual pollution .
Possibility of dam collapsing
Large areas of farmland and wildlife habitats may have to be flooded forcing people and animals to move.
Silt previously spread out over farmland will be deposited in the reservoir
Decaying vegetation in flooded area can release methane and carbon dioxide
So Why Don’t We Use More? Mainly because you need lots of water and a lot of land where you can build a dam and reservoir, which all takes a LOT of money, time, and construction. Ecological Effects:. Run-of-the-River plants can impact the mobility of fish and other river life.
Nearby industrial and domestic demand provide the necessary high head of water Steep upland gradients or former waterfall Cheap land, sparsely populated Impermeable rock – water does not soak through Narrow valleys are ideal for dam construction and water storage Upland areas where narrow valleys with strong and impermeable rock Large and regular rainfall Relief rainfall ( > 1500mm pa) Low rates of evaporation provides a constant supply of water Found mainly in the north and west of the UK in upland areas REASON HEP REQUIREMENTS