The main energy resources are fossil fuels, nuclear fuel, biofuel, wind, hydroelectricity, geothermal, tides, waves, solar and water waves. They are used for transport, electricity generation and heating. Renewable resources are replenished as they are used; non-renewable ones will run out.
Each resource has trade-offs. Fossil fuels are reliable and can respond quickly to demand but release carbon dioxide and, for coal, sulfur dioxide. Nuclear is reliable with no carbon dioxide from generation but produces long-lived radioactive waste and is expensive to decommission. Wind and solar are renewable but depend on the weather and need large areas. Hydroelectric dams are reliable but flood valleys. Choices depend on science, cost, politics, and public opinion.
Worked example
Why do grids keep gas power stations even with many wind farms?
- Wind output changes with the weather.
- Gas stations can be started quickly when demand is high.
Answer:They provide reliable back-up when it is not windy.
Key words
- renewable
- replenished as it is used
- reliability
- how dependable the supply is
- base load
- the minimum continuous demand for electricity
- decommissioning
- safely shutting down a power station
New questions every time.
NGSS-referenced: HS-ESS3-2