Energy sources that aren't finite, such as wind, wave and solar power are of huge benefit to all of us, and these sources are called renewable energy, that is the energy can be easily and naturally renewed. Some forms of energy that will eventually run out, such as biogas collected from a landfill, are seen as renewable, even though the resource is finite.
There are also some energy sources considered renewable that if poorly managed will run out, the best New Zealand example being geothermal energy used to make electricity in the North Island.
Another benefit of renewable energy is that it generally emits little or no greenhouse gas emissions, so they are better for the environment.
Examples of renewable energy include:
- Bioenergy which can be used in a number of ways to generate electricity, heat, or transport fuels from biological materials that store energy, such as wood;
- Geothermal energy which can be harnessed to generate electricity or provide direct heat;
- Hydro energy generated from water flowing through turbines;
- Marine energy such as wave, tidal, and ocean energy devices;
- Solar energy from the sun; and
- Wind energy which can be harnessed to drive wind turbines.
Non-renewable energy is sourced from fossil fuels like coal, oil and gas.
Once they are used, they are gone, and they emit greenhouse gases that contribute to climate change.
Renewable energy plays an important role in New Zealand's energy supply system, with around two-thirds of electricity generated from renewable energy.
Historically, the main renewable sources have been hydro and geothermal.
Concern about climate change and limits on fossil fuel reserves is driving the development and uptake of even more renewable energy technologies to generate electricity, provide heating, and power our vehicles.
The amount of wind energy is still relatively small but with our world-class wind resources it is rapidly growing, while the use of wood energy and other forms of bioenergy is gaining ground.
Nearly all transport in New Zealand relies on fossil fuels. Exceptions include electric trains and buses, and more recently, vehicles running on biofuel blends as an alternative to petrol and diesel. Electric vehicles are likely to become common in the future.
Solar energy is being used both to heat water for homes around the country and to generate electricity by means of photovoltaic panels.
Marine energy is being developed and tested in New Zealand, and holds exciting potential in the near future.
For more information:
- Find out more about EECA's work in renewable energy, including reports and studies.
- The section on distributed generation explains the role of smaller-scale renewable energy in New Zealand.
- Check out the ENERGYWISE™ website for information on generating your own renewable energy (micro-generation).
- The Electricity Commission's 2008 Statement of Opportunities contains up to date costs for large scale renewable electricity and forecasts of future growth.
- The Electricity Commission's Transmission to Enable Renewable project contains links to detailed reports on the economic potential for wind, geothermal and hydro electricity generation.