Benefits & Limitations of Energy Sources (Cambridge International IGCSE Environmental Management)

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

Exam Hint When describing limitations, avoid vague phrases like “bad for the environment”. Instead, use specific impacts such as habitat loss or air pollution. Remember—specificity earns marks.

Also, always try to keep your benefits and limitations tightly linked to the specific energy resource. For example, saying “solar power is intermittent” is correct but may not gain a mark without adding “because it depends on sunlight availability”.