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Renewable energy source
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Advantages
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Disadvantages
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Examples
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Wind
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No air pollution
Can be small or large scale
Can be on land or offshore
Cheap to run, especially onshore
Offshore farms are more efficient and have smaller visual impact
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Can be tricky to find sites with suitable wind speeds - needs to be be above 5 metres per second to turn turbines
Transporting resulting electricity can be expensive
Offshore wind farms are expensive to build and maintain - twice the cost of onshore
Many turbines (233) are needed to produce the same energy as an average coal fired power station
May affect bird migration patterns or kill birds who fly into the moving blades
Noise and visual pollution
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Tamil Nadu, India, has 3600 wind turbines - a third of India’s total wind turbines
The UK’s onshore/offshore wind energy industry is becoming one of the largest in the world
Rampion wind farm built off the coast of Brighton, south east UK, in 2017, has 116 turbines with capacity to supply electricity to 350,000 homes
It cost £1.3 billion but is estimated to displace 600,000 tonnes of CO2 emissions annually, compared to conventional fossil fuel-based electricity generation
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Solar
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No air pollution
Can be small or large scale
Can be used in most locations
Can be incorporated into building design and mixed land use schemes
Technology is improving and reducing cost of solar panels
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Expensive to install
Depends on reliable amount of sunshine hours
Large numbers needed to produce energy
Can use large areas of land
Visual impact on landscape
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Even with the UK’s climate, solar is a viable renewable option
In 2021 the installed solar energy capacity in the UK was around 14 gigawatts, enough to power between 10.5 million and 14 million homes
Germany is a global leader in solar energy. In 2021 solar sources accounted for 10% of the country's total electricity consumption
The potential for solar energy in the southern US is leading to fast expansion
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HEP
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Controls flooding downstream
Often in sparsely populated areas
May provide water storage for irrigation and domestic use
Reservoirs created can be used for tourism - e.g. for water sports and fishing
Dams height can be raised to avoid having to build more
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Large areas of land are flooded behind the dam
Flooded vegetation switches to anaerobic respiration which releases methane
Dam traps sediment which can affect ecosystems downstream
Visual pollution in otherwise picturesque locations
Can prevent fish movement upstream
People and settlements may have to be relocated
Expensive to build and maintain
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In 2020, HEP was the third largest source of energy after coal and natural gas, supplying 17% of global electricity generation
More than 60% of Switzerland’s electricity was generated by HEP in 2021
The largest HEP scheme in the world is the Three Gorges Dam in Hubei, China
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Tidal
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No air pollution
Has the potential to produce large amounts of energy
Reliable as tides are predictable
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Challenging marine environments make barrages expensive to build and maintain - may require government subsidies to make viable
Barrages may affect intertidal ecosystems and shipping
Few suitable sites although technology still in early stages of development
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The UK’s tidal power resource is estimated to be more than 10 gigawatts (GW), about 50% of Europe’s tidal energy capacity
There are no operational tidal power barrages in the UK yet but several have been proposed, for e.g in the Pentland Firth, near the Orkney Islands, Scotland. It is known for its strong tidal currents of up to 16 knots
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Geothermal
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Can produce large amounts of energy
Consistent and reliable source of electricity, known as baseload power.
Geothermal plants can operate continuously, providing a stable power supply without the intermittency issues faced by renewable sources like solar or wind energy
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May only be feasible in specific geographic regions that have accessible geothermal reservoirs on tectonic plate boundaries or hotspots.
High Initial Costs due to drilling and exploration costs associated with identifying suitable reservoirs
Geological uncertainty and risk of encountering dry or low-temperature wells during exploration
Some small environmental issues: e.g. release of geothermal fluids can impact local ecosystems if not managed properly
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26% of Iceland's primary energy supply comes from geothermal energy
The largest geothermal energy scheme in the world is the Geysers Geothermal Complex in California, US
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Biofuels
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Biofuels are derived from organic matter, such as crops, agricultural residues, or waste biomass, so are renewable if replenished through sustainable agricultural practices
Carbon released during combustion is roughly equivalent to the carbon absorbed by the plants during their growth
Can be produced domestically reducing dependence on imported fossil fuels
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Competition between biofuel crops and land that could be used for food production - may contribute to food price increases
Conversion of natural habitats and forests into agricultural land, leading to the loss of biodiversity and ecosystem services
Processing of biofuels is energy-intensive - can offset the environmental benefits of biofuels, particularly if fossil fuels are used extensively during the process (e.g. for harvesting and transport)
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The Sleaford Renewable Energy Plant in Lincolnshire, UK, opened in 2014
Sleaford generates enough electricity to power 65,000 homes by boiling waste straw, which is delivered by 240 lorries each week
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