RENEWABLE ENERGY SOURCES

CASE STUDIES:Wind Power – North Hoyle,

WalesHEP – Three Gorges Dam,

China

HOW MUCH DO YOU KNOW ABOUT NON-RENEWABLES? TRUE OR FALSE

1. Coal is estimated to run out by 2200.

2. App 99% of energy in the UK in 2003 came from non-renewable energy sources.

3. The Kyoto Protocol was an agreement to reduce use of CFCs.

4. All countries have signed the Kyoto Protocol.

5. It was part of the United Nations Framework Convention on Climate Change (UNFCCC).

6. The agreement came into force on Feb 16th 2003.

7. Methane is a type of greenhouse gas.

8. Some countries such as China & India do not have to reduce emissions under the Kyoto Agreement.

9. The EU produces about 22% of global greenhouse emissions.

10. The EU can issue fines to countries within the EU who do not meet their obligations.

11. In the UK a bill has been presented to state that the UK will reduce carbon emissions by 60% by the year 2050.

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?

What are the main types of renewable energy?

• Solar• Wind• Wave• Tidal• Hydro-electric• Geothermal

often located in exposed areas such as mountainous regions

Wave

Solar

Geothermal

Wind

HEP

Tidal

TEST YOURSELF - MATCH THE STATEMENT WITH THE ENERGY SOURCE

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

heat produced by rocks under the Earth’s surface

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

Wind energy

Inside a wind turbine

Wind energy is created from wind turbines. Blades on the turbine turn as the wind blows and this is connected to a generator inside the turbine.

Several turbine together are called a wind farm.

Wind energy - the disadvantages

Some people also consider the wind farms as visually unattractive and noisy.

What are the advantages of wind energy?

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.

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.

Advantages of wind energy

cooling towers

Wind power can be developed on a small scale.

Wind farms create jobs in rural areas.

Wind farms can be constructed in a few months (thermal power stations take

between 6-10 years to complete).

Wind fuel is free.

Wind turbines need to be in areas with regularly high wind speeds. This means that exposed coasts or upland areas are best. There are 93 sites in the UK at present.

Wind farms are now also built offshore. Two are already operating and there are plans for thirteen more.

Important location factors for wind farms

Wind power will provide 1.3% of the UK’s electricity supply by the end of 2005 (UK Energy in Brief, July 2003).

© Ed Linton / DOE - NREL

Where should the new wind turbines be located?

12

3

It has been decided to locate new wind turbines in this area. Choose from the three sites indicated and justify your answer.

wind direction

town

Case Study:North Hoyle Offshore Wind

FarmWhen did the construction of North Hoyle offshore wind-farm begin?

Built in 2003

Describe the location of North Hoyle offshore wind-farm.

The project is located 4-5 miles off the North Wales coast between Rhyl and Prestatyn. It covers an area of approximately 10km2. Why?It offers an ideal combination of relatively shallow waters, good strong winds and proximity to the national electricity network.

How many turbines are at North Hoyle offshore wind-farm?

30 turbines each rated at 2 megawatts

What are the advantages of North Hoyle for the location of a wind farm?

WHAT ARE THE ADVANTAGES OF THE NORTH HOYLE OFFSHORE WIND-FARM?

1. COMMUNITYnpower renewables has set up the North Hoyle Offshore Wind Farm Community Fund in partnership with Denbighshire County Council and the Area Partnerships for Rhyl and Prestatyn & Meliden. The Community Fund, set up as part of the North Hoyle project, is ploughing £60,000 into the communities of Rhyl and Prestatyn & Meliden every year for the 20 year life of the wind farm.Will provide power for 200,000,000 kWh (units) enough for app 40000 homes.

2. ENVIRONMENTDoes not produce harmful pollutants or damaging gas emissions that contribute to climate change. Approx. 160000 less tonnes of CO2 in atmosphere.It is sustainable energy.

3. EDUCATIONWork with 20 local schools to raise profile of alternative energy sources and problems of climate change. Have a classroom on site for local schools to visit.

4. JOBSFor example, 10 full-time positions in operations and maintenance at the North Hoyle Offshore Wind Farm project have been filled by people living locally to the project. In addition, there is evidence to suggest that the wind farm has had a positive impact on tourism in the area.

WHAT ARE THE DISADVANTAGES OF THE NORTH HOYLE OFFSHORE WIND-FARM?

1. Damage to the seabed and therefore some marine habitats.

2. Noise disturbance for local wildlife & danger of birds flying into rotor blades.

3. Expensive to build

4. Could disrupt shipping routes.

5. Easily damaged in storms

Hydroelectric power

Hydroelectric electricity is the most popular type of renewable energy. Hydroelectric energy is produced from fast flowing water, such as at a waterfall or by an artificial dam.

Hydroelectric power - impact of building dams

tourists may be attracted to the area

silt is trapped behind the dam and is not transported downstream where it is needed for farmers and fishermen

may decrease flooding downstream

the water behind the dam is stagnant and algae builds up

building dams floods large areas

dams control the flow of water

These are some of the advantages and disadvantages of building a dam. Explain one advantage and one disadvantage in more detail.

The Three Gorges Dam project is the largest undertaking by the Chinese since they built the Great Wall.

When it is finally completed in 2009 it will be the largest hydroelectric scheme in the world,

Three Gorges Dam project in China

generating thousands of megawatts ofelectricity to meet the demands of China’s growth. It will create a reservoir that will span 410 miles and make the Yangtze the longest navigable river in the world. 

Impacts of the Three Gorges DamAdvantages Disadvantages

Will help prevent loss of life downstream as it will control flooding.

2.3 million people have been forced out to build the dam/lake.13 cities, 140 large villages and hundreds of small villages have been flooded to create the lake.The stagnant water could lead to an increase in diseases.1300 archaeological sites will be lost.

Once finished it will provide reliable & cheap energy source that could provide 10% of China’s energy needs.There is improved industry in the area as large cargo ships can now go 1500 miles inland.It provides jobs for the people building the dam and afterwards.

3000 farmers have lost their land to the lake.Building costs are nearly $30 billion.Historical & archaeological sites lost could mean less tourists.

It will reduce China’s reliance on coal fired power stations so there will be less harmful emissions.

Threatens rare species like the Baiji river dolphin.There could be problems of silt building up in the lake.Human and industrial waste could pollute the lake waters.

Solar energy

Solar panels

Photovoltaic cells are made of the abundant element silicon.

Photovoltaic cells are silent.

Photovoltaic cells have low maintenance costs.

Why isn’t solar energy popular in the UK?

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. Tidal energy is generated at La Rance in western France. A suitable site in Britain would be the River Severn. This barrage would cost between £3 billion and £9 billion and be able to generate between 5% and 10% of Britain’s total electricity demand.

Tidal energy

Wave energyThe island of Islay, off the west coast of Scotland has had a Limpet (land-installed marine-powered energy transformer) constructed, which should provide a reliable electricity supply for the 3,400 residents. A 25-metre notch has been cut into Islay’s south west facing cliffs at Portnahaven into which a wave chamber has been inserted. The waves rise and fall in this wave chamber compressing the air and so driving the turbines which power the generators.

Why has the wave chamber been placed on the south west of the island?

incoming waveslow tide

high tide

turbo generator

Geothermal energy

Hot water Cold Water

geothermal plant

fractured rock

Geothermal energy is obtained from heated rocks and molten magma under the Earth’s surface.