Solar radiation is an abundant energy source which is free, non-polluting, and renewable.
New Zealand has good solar radiation levels in many locations. Radiation levels in Invercargill are roughly as high as in Germany, where solar panels are commonly used.
Hours of bright sunshine in New Zealand
Many New Zealand homes are exposed annually to 20 - 30 times more energy from the sun than they use in electricity or gas, yet this energy source is vastly under-developed.
On average, New Zealand has about 2000 hours of bright sunshine each year. In energy terms, New Zealand's solar energy resource is about 4 kWh/m2 per day. To put that in perspective, if every New Zealand home had a 3kW photovoltaic (solar) panel array, they would collectively generate enough power in a year to satisfy over a quarter of New Zealand's annual residential electricity needs.
The energy of the sun can be harnessed in many ways
You can use the sun's thermal energy to warm water or space through:
- Thoughtful building design to capture and store solar heat
- Use of solar water heating which uses the energy of the sun to heat water.
You can use energy available in sunlight to generate electricity directly through:
- Photovoltaic panels which use semiconductors to generate electricity
- Concentrator solar power technologies which use mirrors to focus the sun's thermal energy, and use super-heated steam to drive a turbine to generate electricity.
Promoting solar energy use
Around 1.6% of homeowners in New Zealand have now installed solar water heating systems, and currently there are around 3400 new solar water heating systems installed each year. This number is growing at around 30-40% annually.