1. Renewable Energy

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

3. 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?

4. 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?

5. Wind energy

6. 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?

7. 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.

8. 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 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

9. Hydroelectric power

10. 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.

11. 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

12. 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

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

14. 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

15. 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