Solar Power for Homes



Solar power is certainly a clean energy source and if the sun shines it will continue to be freely available and will reduce New Zealand's greenhouse gas emissions if it replaces power produced by fossil fuels.

The commonly seen solar panels collect energy from the sun and convert it into electricity. The electricity produced is direct current and needs to be changed to alternating current which is the type used in houses.

This requires a unit called an inverter. The system is usually used in conjunction with the normal power supply to reduce the amount of electricity used from the national grid and so cut the users electricity bills. 

Any excess electricity produced can be sold to the electricity retailers and fed into the grid but paid to you at a much lower cost than buying it. Because solar only produces electricity during daylight hours most systems are connected to the grid for when there is no or insufficient solar supply. 

The cost of batteries for storage to avoid this are presently too expensive to be worthwhile. For houses in remote areas where the cost of getting connected to the electricity grid may be very difficult and/or costly the use of storage batteries and/or backup generators are an option.

Solar works best where there is a large number of sunshine hours such as Nelson/Marlborough but in general New Zealand has good sunshine hours suitable for solar energy. 

The cost of batteries for storage in particular and of solar panels and inverters are becoming more and more efficient and the costs are gradually coming down. 

At the moment however the typical time for the savings on electricity charges from the grid to make the payback period for the investment in solar energy is a long-term investment.

It will usually take at least 10 years and more typically around 15 years to recoup the investment at present day costs. A lot can happen in that time. 

Electricity charges from the grid could increase significantly especially if demand grows as more electric cars come into use. For many solar panels for homes will be a wait and see exercise.