Wind energy is harnessed through the use of wind turbines - normally tall towers with three propeller blades (vanes) that appear frequently around the UK.
The blades turn with the wind, driving a generator, which produces the electricity. While there are many dotted around the countryside as single towers or in a small group, they are now more commonly grouped together off-shore in large quantities to form a wind farm.
|Advantages of wind||Disadvantages of wind|
|Wind energy is constantly available and sustainable||When there are periods of low wind, little or no energy is produced|
|There is no cost for wind and the running cost of a wind turbine is relatively low||They cost a lot to build and put in place|
|Some people do not like the look of wind turbines or feel that they spoil the natural landscape|
Solar panels are made from photovoltaic cells, which harness the Sun’s light energy and convert it into electricity. Solar power provides clean energy from a plentiful supply, but there is still considerable development work to be done to try to make solar panels more efficient. The placement of the solar panels is also very important to ensure they track the path of the Sun and harness the optimum amount of solar energy.
|Advantages of solar||Disadvantages of solar|
|Clean, renewable energy source||Some people do not like the look of solar panels or feel that they spoil the appearance of a building|
|Reduces household energy bills||Costs a lot to install|
|Does not produce much electricity when there is considerable cloud cover, during the winter months or at night|
The UK currently only generates a small amount of energy from tidal power, but it is estimated that the UK could potentially harness around a fifth of its electricity demand in this way. Tidal energy relies on the gravitational pull of the Moon, which causes the change in water levels known as tides.
A tidal barrage is built across the mouth of a river where it meets the ocean. The barrage is constructed so that the incoming tide passes through turbines to generate electricity. It also harnesses the reverse flow of the water when the tide goes out.
|Advantages of tidal||Disadvantages of tidal|
|Clean, renewable energy source||Construction of tidal barrages is expensive|
|Tidal power plants will last for a long time||Environmental impact of tidal barrages is unknown|
|Could produce a fifth of the UK’s needs as it is an island surrounded by the sea|
Once the water has built up behind the dam, it is directed and released by valves through turbines. The turbines turn generators to produce electricity.
|Advantages of hydroelectric||Disadvantages of hydroelectric|
|Clean, renewable energy source||Construction of dams is expensive|
|Valves can be opened very quickly to produce energy at peak times||Objections from people in the surrounding environment|
|No pollution when running it||Affects the wildlife by flooding the valley|
Biomass energy involves growing plants or using animal materials, not for consumption but so that they can be burned to produce heat. Plants such as rapeseed or willow are specifically grown as biomass crops so that they can be burned in a furnace.
|Advantages of biomass||Disadvantages of biomass|
|Clean, renewable energy source||Creates atmospheric pollution when burned|
|Carbon dioxide is released in the process and can be reused by plants||Land used for energy crops may be needed for other purposes such as agriculture|
|Replacement plants can be grown very quickly to ensure a good supply|