Hydro Electric Power (HEP)
On the Earth, water is neither created nor destroyed, but is constantly moved around. Water evaporates from the oceans, forming clouds, falls out as rain and snow, collects into streams and rivers, and flows back to the sea. This is known as the water cycle.
All this movement provides an enormous opportunity to create useful energy. Hydroelectric power (HEP) uses the force of moving water to create electricity. However, HEP stations often require large dams, which can disrupt ecosystems and displace people.
There are a number of large-scale HEP stations currently in operation throughout Britain. In Scotland they are responsible for providing a significant amount of energy. Unfortunately there is little room for the future development of large scale HEP stations in Britain and so
the potential of small-scale HEP stations is now being investigated.
Rocks under the Earth’s crust contain naturally decaying radioactive materials like uranium and plutonium, producing a continuous supply of heat. The amount of heat within 10,000 metres of the Earth’s surface contains 50,000 times more energy than all the oil and gas resources in the world.
Geothermal energy is power generated by the harnessing of heat beneath the Earth’s surface. Wells are used to pipe steam and hot water from deep within the Earth, up to the surface. The hot water is then used to drive turbines and generate electricity. The regions with highest underground temperatures are in areas with active or geologically young volcanoes. These “hot spots” often occur around the Pacific Rim. This area is also known as the “Ring of Fire” due to the large number of volcanoes.
In the UK at a depth of about 1500 - 3000 metres below the surface there are some aquifers that contain water at very high temperatures. This water can be pumped up to the surface and used in heating schemes.
The idea of tidal power is very similar to HEP. A dam-like structure is constructed across an estuary to trap a high tide of water and then let it pass through turbines to generate electricity. The water flow can generate electricity on the falling tide only, or on the falling and rising tide. The Rance Estuary in France (Brittany) is an example of a successful tidal plant. The UK has the potential to widely use tidal power with the Severn and Mersey estuaries being possible sites.
Hydro Electric Power