Key definitions
Non-renewable energy — an energy source that is finite and cannot be replenished. It usually has negative impacts on the environment.
Renewable energy — an energy source that is naturally replenished and usually does not come with negative impacts to the environment.
Factors that affect an energy source
- Physical factors — location, geology and availability of energy sources
- Technology — the advancements made to exploit and access new sources
- Climate — the amount of sunshine or wind (needed for some energy sources)
- Political factors — the supply of energy imported from another country (for countries that buy energy from other countries)
Renewable energy sources
| Source | Advantages | Disadvantages |
|---|---|---|
| Biomass | Reliable; an abundant source IF managed sustainably | Expensive; produces greenhouse gases |
| Wind | Running costs are low; doesn't take up too much land | Expensive; unreliable |
| HEP (hydroelectric power) | Reliable; produces large amounts of energy | Expensive; habitats are destroyed for the land |
| Geothermal | Reliable | Expensive; must be close to a volcano |
| Wave | Reliable | Expensive; unattractive |
| Solar | Running costs are low | Expensive; takes up a lot of space; unattractive; unreliable |
How renewable energy sources work
The source either spins a turbine which generates electricity, or is used as fuel to boil water, turning it into steam used to spin a turbine (which generates the electricity).
Non-renewable energy sources
- Oil
- Natural gas
- Coal
- Nuclear energy
Nuclear energy
| Advantages | Disadvantages |
|---|---|
| Cheap and reliable once built | Expensive to build |
| Clean and safe | May run the risk of meltdowns |
| Provides jobs for a long time (500 staff for 35 years) | Disposal of waste can be harmful for health |
| Provides jobs during construction (1200 people) | Has radioactive waste products and will pollute earth for hundreds of years |
| Can be disposed of safely | Uranium used may have to be imported |
Case study: Energy supply in a country — Iceland
- Located on the constructive plate boundary between the North American and Eurasian plates: the Mid-Atlantic Ridge.
Facts
- 66% of energy and 25% of electricity in Iceland is geothermal.
- 15% of energy and 75% of electricity in Iceland is HEP energy.
- 81% of Iceland's energy is sustainable.
- 19% of Iceland's energy comes from imported fossil fuels.
- The Karahnjukar project is a HEP project that provides 750 jobs in Iceland.