A renewable resource is replenished as it is used, or can be replenished. A non-renewable resource is used faster than it is replaced and has a finite supply.
| Renewable | Non-renewable |
|---|---|
| Wind, solar, hydroelectric, tidal, waves, geothermal | Coal, oil, natural gas, nuclear fuel |
| Biofuel, if its source is replenished sustainably | Fossil fuels take millions of years to form |
| Resource | Reliability and environmental considerations |
|---|---|
| Fossil fuels | Output can be controlled while fuel is available. Burning releases carbon dioxide; some emissions cause air pollution. |
| Nuclear fuel | Reliable output and low operational carbon dioxide emissions; radioactive waste and high construction/decommissioning costs. |
| Wind and solar | No fuel burned during generation, but output varies with wind or sunlight. Storage or other supplies can help. |
| Hydroelectric | Stored water can provide controlled output, but reservoirs flood land and affect habitats; rainfall matters. |
| Tides and waves | Tides are predictable but output is not continuous. Waves depend on weather; marine habitats may be affected. |
| Geothermal | Can provide reliable heating or electricity in suitable locations; useful sites are limited. |
| Biofuels | Can be regrown, but burning releases carbon dioxide. Land use, food competition and regrowth affect sustainability. |
Transport: petrol and diesel from oil, biofuels, or electricity from a mix of resources.
Heating: natural gas, electricity, biofuels, geothermal or solar heating.
Electricity: a mix of resources can balance reliability and environmental impact.
Electricity is a way of transferring energy, not itself a primary energy resource. A renewable resource is not automatically impact-free.
The table is an illustrative electricity mix, not current national statistics.
| Example year | Renewables | Other resources |
|---|---|---|
| Year 1 | 20% | 80% |
| Year 2 | 40% | 60% |
The renewable share rose by 20 percentage points. To explain choices, consider reliability, cost, location and environmental impact.
Science identifies impacts, but political decisions, public views and costs also affect which resources are used.
Compare renewability, reliability, environmental impact, location and cost. No resource is ideal in every situation.
Build confidence with pictures, clues and instant feedback.
Use the pictures to help you.
One point for each answer you get right first time.
No timer. Take your time and use a clue whenever you need one.