What are the renewable and non-renewable energy sources and their impacts?
the characteristics, advantages and disadvantages of non-renewable energy sources (fossil fuels, nuclear) and renewable energy sources (solar, wind, hydro, geothermal, biomass)
A focused answer to the VCE Environmental Science Unit 4 dot point comparing non-renewable and renewable energy sources and their advantages and disadvantages, with Australian examples.
Reviewed by: AI editorial process; not yet individually human-reviewed
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What this dot point is asking
VCAA wants you to classify energy sources as renewable or non-renewable, describe their characteristics, and evaluate the advantages and disadvantages of each. A strong answer defines the source, names a real example, and weighs costs against benefits.
Non-renewable energy sources
Non-renewable sources exist in finite amounts and are not replenished on a human timescale.
Fossil fuels (coal, oil, natural gas). Formed from ancient organic matter over millions of years. Burning them releases stored chemical energy and large quantities of carbon dioxide, the main driver of the enhanced greenhouse effect. Australia has long relied on coal-fired power stations such as those in Victoria's Latrobe Valley (brown coal).
- Advantages: energy-dense, reliable, established infrastructure, dispatchable (available on demand).
- Disadvantages: greenhouse gas and air pollution emissions, finite supply, environmental damage from mining and extraction, oil spills.
Nuclear. Energy released by nuclear fission of uranium. It produces almost no greenhouse gas during operation and very high output from a small amount of fuel. Australia mines and exports uranium but does not generate nuclear electricity.
- Advantages: very low operating emissions, high and reliable output, small land footprint.
- Disadvantages: long-lived radioactive waste, very high upfront cost and long build times, accident risk, finite uranium supply.
Renewable energy sources
Renewable sources are naturally replenished and effectively inexhaustible on a human timescale.
Solar. Photovoltaic panels convert sunlight to electricity; solar thermal systems concentrate heat. Australia has abundant sunshine and high rooftop-solar uptake.
- Advantages: no operating emissions, fuel is free, scalable from rooftops to large farms.
- Disadvantages: variable (no output at night, less when cloudy), needs storage or backup, large-scale farms use land.
Wind. Turbines convert the kinetic energy of wind into electricity, as at large wind farms in Victoria and South Australia.
- Advantages: no operating emissions, low running cost, land beneath turbines can still be farmed.
- Disadvantages: intermittent, can affect birds and bats, visual and noise concerns.
Hydroelectricity. Moving water drives turbines, as in the Snowy Mountains Scheme.
- Advantages: reliable, dispatchable, can store energy via pumped hydro (Snowy 2.0).
- Disadvantages: dams flood habitats, alter river flows and block fish migration, limited to suitable sites.
Geothermal. Heat from within the Earth drives turbines or heats buildings. Limited in Australia but used in some hot-rock trials.
- Advantages: reliable baseload, very low emissions, small footprint.
- Disadvantages: restricted to geologically suitable areas, high drilling costs.
Biomass. Energy from organic material (crop waste, wood, biogas from landfill or manure). Considered renewable when the source is regrown.
- Advantages: uses waste, can be dispatchable, roughly carbon-neutral if replanted.
- Disadvantages: burning still produces emissions and air pollution, can compete with food crops for land.
Weighing it up
No single source is perfect. Fossil fuels are reliable but high-emitting; nuclear is low-carbon but produces hazardous waste; renewables are clean but most are variable and need storage (batteries, pumped hydro) and grid upgrades to provide steady supply. Australia's transition combines abundant solar and wind with storage to firm the variable supply.
Exam-style practice questions
Practice questions written in the style of VCAA exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
2025 VCAA4 marksProposals have been made to introduce nuclear power in Australia, constructing several nuclear power plants. Discuss the implications of using nuclear power as an energy source in terms of each of the following: greenhouse gas emissions; a reliable energy source.Show worked answer →
Two marks for each aspect, giving a balanced discussion.
Greenhouse gas emissions (2 marks): nuclear fission generates electricity without burning fossil fuels, so it produces almost no greenhouse gas during operation, which is an advantage for reducing emissions. However, there are some emissions across its life cycle (mining and enriching uranium, and building the plant), so it is low-carbon rather than zero-carbon.
A reliable energy source (2 marks): nuclear is a reliable, dispatchable baseload source that can run continuously day and night regardless of weather, unlike intermittent solar and wind, giving steady output. The trade-off is the very long build time and high cost, and the need to manage long-lived radioactive waste safely, which affects how readily this reliability is achieved.
2023 VCAA2 marksGeothermal energy is heat from the earth brought to the surface using steam or water and converted into electricity at a power station. Explain why geothermal energy could be used to supply base load energy.Show worked answer →
A 2 mark answer links the constant heat source to continuous supply.
1 mark: base load is the minimum continuous level of electricity demand that must be met at all times, day and night.
1 mark: geothermal draws on heat stored within the Earth, which is available continuously and is not dependent on weather or time of day (unlike solar or wind). It can therefore generate a steady, reliable output around the clock, making it suitable to supply base load energy.
2022 VCAA2 marksA region has begun extracting coal seam gas for gas-fired turbines, while a neighbouring region has decided to construct a large-scale wind farm instead of using its coal seam gas. Describe the key environmental reason why a region would opt to use wind energy rather than a coal seam gas resource.Show worked answer →
A 2 mark answer contrasts emissions.
1 mark: coal seam gas is a fossil fuel, and burning it in turbines releases carbon dioxide (a greenhouse gas) into the atmosphere, contributing to the enhanced greenhouse effect and climate change.
1 mark: wind is a renewable source that generates electricity from the kinetic energy of wind with no fuel combustion and essentially no greenhouse gas emissions during operation. Choosing wind therefore greatly reduces the region's greenhouse gas emissions, which is the key environmental reason.