Solar radiation is an abundant energy source which is free, non-polluting, and renewable. New Zealand has good solar radiation levels in many locations, but often the cost of the systems required to harness solar energy mean they aren't economic when compared to other options.
How it works
The energy of the sun can be harnessed in many ways.
The sun's thermal energy can be used to warm water or the air in a building 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.
The energy available in sunlight can generate electricity directly through:
- photovoltaic (PV) panels which generate electricity
The pros and cons of solar energy
Solar radiation is an abundant energy source in New Zealand. The most popular solar technology, photovoltaics (PV), is non-polluting, quiet to operate, and generally unobtrusive.
However PV is generally not cost-effective even though prices have reduced considerably. At a national level, New Zealand has many cheaper renewable generation options than solar PV (for example, wind, geothermal and hydro). PV also only operates when the sun is shining, so it requires back up at night and on cloudy days. It is of little use at times of peak electricity load (evenings and in winter) unless the electricity is stored in batteries. Grid-connected PV (without batteries) cannot be used in the event of power cuts.
Solar energy is becoming popular in many countries especially where they want to reduce carbon emissions in the energy sector. The reason for this popularity is that they have few renewable resources available for electricity generation. In many cases it is cheaper and easier for them to offer subsidies for people to install solar hot water or PV than to address the issue other ways.
In New Zealand, however, our highly renewable electricity system means the environmental benefits that can be gained from switching to solar energy are slight (or non-existent).
Place in New Zealand energy system
About 2% of homeowners in New Zealand have solar water heating systems. Only about 0.2% of homes have grid connected PV systems, but uptake of PV is increasing.
Role for EECA
Due to the lack of national benefit, there is no good imperative for a government subsidy or support for solar energy technologies like PV. EECA will continue to provide independent information about solar PV for consumers so they can decide if PV is right for them.