Benefits & Limitations of Energy Sources (Cambridge (CIE) IGCSE Environmental Management): Revision Note

Benefits & limitations of renewable energy sources

Bioethanol

Benefits of bioethanol

• Burns cleaner than petrol, producing fewer pollutants

• Can be blended with petrol, reducing fossil fuel use

• Made from fast-growing crops like sugarcane or maize that can be harvested regularly

Limitations of bioethanol

• Has a lower energy content than petrol, so more fuel may be needed

• Large areas of land may be used for fuel crops instead of important food crops needed to feed people

Biomass

Benefits of biomass

• Can be burned in existing power stations with small changes to equipment

• Often made from plant waste or wood scraps, reducing landfill

• Renewable and potentially carbon neutral when forests or crops are replanted regularly

Limitations of biomass

• Burning biomass releases carbon dioxide and causes particulate pollution

• Needs a constant supply of organic material, which may be difficult to sustain

• Transporting bulky biomass fuel uses energy and creates emissions

Biogas

Benefits of biogas

• Made from waste materials like manure, sewage or food waste, reducing landfill

• Captures methane that would otherwise enter the atmosphere

• Provides a useful and available energy source for farms and rural areas

Limitations of biogas

• Requires a steady supply of organic waste, which is not available everywhere

• Biogas systems can be expensive to install for small users

• Poorly managed plants can create unpleasant smells

Wood

Benefits of wood

• Widely available in many rural and forested areas

• Can be a low-cost fuel when sourced sustainably

• Wood waste from forestry can be used as fuel instead of being thrown away

Limitations of wood

• Burning wood releases smoke and particulates, affecting air quality

• Unsustainable harvesting causes deforestation and habitat loss

• Wood has a relatively lower energy density, so more fuel is needed to produce the same amount of energy

Geothermal power

Benefits of geothermal power

• Reliable energy supply available at all times

• Very small land footprint

• Low running costs once the plant is built

• Long operational lifespan

Limitations of geothermal power

• Only possible in areas with suitable geological conditions

• Very high drilling and exploration costs

• Can release underground greenhouse gases

• Risk of small earthquakes or ground movement

Hydro-electric power

Benefits of hydro-electric power

• Reliable and predictable energy source

• Low greenhouse gas emissions during operation

• Provides extra benefits like flood control and irrigation

• Can generate large amounts of electricity quickly

• Long lifespan and low operating costs

Limitations of hydro-electric power

• Dams disrupt river ecosystems and fish migration

• Very high cost to build dams and reservoirs

• Flooding of land destroys habitats and may displace communities

• Climate change can reduce water availability in reservoirs

Tidal power

Benefits of tidal power

• Predictable and reliable due to regular tidal cycles

• Produces no greenhouse gas emissions during operation

• Long lifespan with low maintenance

• Can generate large amounts of electricity at short notice

• Low visual impact when underwater

Limitations of tidal power

• Expensive to build tidal barrages or lagoons

• Only a few suitable coastal sites

• Can disturb marine ecosystems and fish migration

• Difficult and costly to maintain underwater equipment

• May interfere with shipping and transport routes

Wave power

Benefits of wave power

• Abundant energy source in coastal areas

• No greenhouse gas emissions during operation

• Low visual impact compared to wind farms

Limitations of wave power

• Technology is still developing and expensive

• Only suitable in areas with strong, regular waves

• Can affect marine habitats and navigation

• Maintenance can be challenging due to rough sea conditions

Solar power

Benefits of solar power

• Abundant and widely available energy source

• Produces no greenhouse gas emissions during operation

• Works on small and large scales

• Can be installed on existing buildings

• Useful in remote areas without electricity grids

Limitations of solar power

• Intermittent energy source depending on sunlight

• High installation cost for panels and equipment

• Solar farms need large land areas

• Electricity storage needed during night or cloudy days

• Manufacturing and disposal create electronic waste

Wind power

Benefits of wind power

• Abundant energy source in many locations

• Produces no greenhouse gas emissions during operation

• Land around turbines can still be used for farming

• Can be installed offshore to reduce land conflicts

• Costs have fallen, making it competitive with fossil fuels

Limitations of wind power

• Intermittent energy source depending on wind

• Causes visual and noise pollution

• Large wind farms need wide areas of land

• Risk to birds and bats flying into blades

• High installation cost

Benefits & limitations of non-renewable energy sources

Fossil fuels (coal, oil, natural gas)

Benefits of fossil fuels

• Existing infrastructure already built to use them

• Often readily available and relatively easy to transport

• Historically reliable for large-scale electricity production

• High energy density produces lots of energy per kilogram

Limitations of fossil fuels

• Non-renewable because they take millions of years to form

• Increasing demand and decreasing supply raises prices

• Release carbon dioxide and sulphur dioxide when burned

• Can cause oil spills that harm marine environments

• Prices and supplies are significantly affected by global conflicts

Nuclear power (uranium)

Benefits of nuclear power

• Produces no atmospheric pollution during operation

• Reliable for continuous, large-scale electricity supply

• Requires small amounts of uranium fuel

• Reduces reliance on fossil fuels and increases energy security

Limitations of nuclear power

• Uranium is finite, so nuclear energy is non-renewable

• Produces radioactive waste that must be stored safely

• Waste storage and safety systems are extremely expensive

• Accidents can release harmful radiation

• Decommissioning power stations costs a lot