Renewable Energy

Does the UK need alternative energy supplies? energy sources (UK 2003)

Renewable energy sources These will not run out because they can be regenerated. Examples are wind power, solar power, tidal power and biomass. Charcoal - a fuel produced from wood (biomass) Only 1% of the UK’s energy comes from these sources. Can you think of a reason why?

Why isn’t solar energy popular in the UK? Photovoltaic cells are made of the abundant element silicon. Photovoltaic cells have low maintenance costs. Photovoltaic cells are silent. Solar panels Why isn’t solar energy popular in the UK?

Wind energy

Wind energy - the disadvantages In theory, the UK could generate all its electricity from wind farms covering approximately 1% of the land. But the problems are wind turbine design and cost. Rotor blades can be damaged in strong and turbulent winds. It takes 30 wind farms to generate the same amount of electricity as one coal-fired power station. The setting up costs for wind farms are therefore more expensive than for traditional, fossil fuel power stations. Some people also consider the wind farms as visually unattractive and noisy. What are the advantages of wind energy?

Advantages of wind energy Wind farms create jobs in rural areas. Wind fuel is free. Wind farms can be constructed in a few months (thermal power stations take between 6-10 years to complete). cooling towers Wind power can be developed on a small scale.

Hydroelectric power Hydroelectric electricity is the most popular type of renewable energy. In some countries, such as Brazil, it represents most of the energy produced. Hydroelectric energy is produced from fast flowing water, such as at a waterfall or by an artificial dam. Teacher’s notes Hydroelectric schemes are divided into two categories: large-scale (more than 5MW) and small-scale (less than 5MW). Both small-and large-scale schemes have generally the same requirements: a suitable rainfall catchment area a hydraulic head (the vertical distance from the reservoir or river to the turbine) a water intake placed above a weir or behind a dam a system of controlling the water flow a turbine, generator and grid connection an outflow, where the water returns to the main water course. Although there is little scope to build further large-scale hydro power schemes in the UK, there is potential for more small-scale projects. The Elan Valley scheme in the Cambrian Mountains of mid-Wales comprises five reservoirs and four dams, built between the end of the 19th century and 1952. The reservoirs hold 199 million tonnes of water and are the main water supply source for Birmingham. During the 1990s, the existing water supply was harnessed to generate electricity. The scheme generates power to meet the needs of nearly 11,000 homes, avoiding carbon dioxide (CO2) emissions of 26,200 tonnes a year. Dam at Donzere, France

Hydroelectric power

building dams floods large areas Hydroelectric power - impact of building dams silt is trapped behind the dam and is not transported downstream where it is needed for farmers and fishermen may decrease flooding downstream dams control the flow of water the water behind the dam is stagnant and algae builds up tourists may be attracted to the area building dams floods large areas These are some of the advantages and disadvantages of building a dam.

Tidal energy Energy is generated by the tidal rise and fall. The tides come in and pass through holes in a dam wall. The water is then trapped in a river estuary. Then the tide ebbs and passes back through the barrage, driving the turbines and producing electricity. turbo generator high tide low tide incoming waves

Geothermal energy Geothermal energy is obtained from heated rocks and molten magma under the Earth’s surface. geothermal plant Hot water Cold Water fractured rock

Geothermal energy is generated extensively in tectonic areas, such as Iceland and New Zealand. Why is this the case? Plate Map

Match the statement with the energy source heat produced by rocks under the Earth’s surface water stored in dams is released through turbines to generate electricity located on the coast with a chamber facing the prevailing wind mirrors concentrate the sun’s rays onto water-filled black pipes powered by a man-made barrage, usually found across an estuary often located in exposed areas such as mountainous regions located on the coast with a chamber facing the prevailing wind Wave often located in exposed areas such as mountainous regions Solar mirrors concentrate the sun’s rays onto water-filled black pipes HEP heat produced by rocks under the Earth’s surface Tidal Answers appear on click powered by a man-made barrage, usually found across an estuary Wind Geothermal water stored in dams is released through turbines to generate electricity

Biomass is biological material from living, or recently living organisms, such as wood, waste, (hydrogen) gas, and alcohol fuels. Biomass is commonly plant matter grown to generate electricity or produce heat. Biomass energy is comes from five distinct energy sources: garbage wood, waste, landfill gases alcohol fuels. Answers appear on click Biomass can be converted to other usable forms of energy like methane gas or transportation fuels like ethanol and biodiesel