Hydro-electric Power uses Falling Water

• Hydro-electric power usually requires the flooding of a valley by building a big dam. Water is allowed out through turbines. There is no pollution.

• But theres a big impact on the environment due to the flooding, rooting vegetation releases methane and CO2, and possible loss of habitat for some species. The reservoirs can also look very ugly when they dry up. Putting hydroelectric power stations in remote villages tends to reduce their impact on humans.

• A big advantage is it can provide an immediate response to an increased demand for electricity

• There’s no problem with reliability except in times of drought-but remember this is Great Britain we’re talking about

• Initial costs are high, but there are no fuel costs and minimal running costs

• It can be a useful way to generate electricity on a small scale in remote areas

Wave Power-Lots of Little Wave-Powered Turbines

• You need lots of small wave-powered turbines located around the coast. Like with wind power, the moving turbines are connected to a generator.

• There is no pollution. The main problems are disturbing the seabed and the habitats of marine animals, spoiling the view and being a hazard to boats.

• They are fairly unreliable, since waves tend to die out when the wind drops

• Initial costs are high, but there are no fuel costs and minimal running costs. Wave power is never likely to provide energy on a large scale, but it can be very useful on small islands.

Tidal Barrages-Using the Sun and Moon’s Gravity

• Tides are used in lots of ways to generate electricity. The most common method is building a tidal barrage

• Tidal barrages are big dams built across river estuaries, with turbines in them. As the tide comes in it fills up the estuary. The water is then allowed out through the turbines at a controlled speed.

• Tides are produced by the gravitational pull of the Sun and Moon

• There is no pollution. The main problems are preventing free access by boats, spoiling the view and altering the habitat of the wildlife.

• Tides are pretty reliable as they happen twice a day without fail. The only drawback is that the height of the tide is variable so lower tides will provide significantly less energy than the bigger spring tides. They also don’t work when the water is the same either side of the barrage-this happens four times a day because of the tides

• Initial costs are moderately high, but there are no fuel costs and minimal running cots. Even though it can only be used in some of the most suitable estuaries tidal power has the potential for generating a significant amount of energy.