Using renewable energy is an option for a variety of reasons. Practicality and cost to be connected to the electrical grid is the primary reason. The second is for people who like the idea of being independent and not relying on the grid for electricity and for environmentally conscious people.


Using alternative energy can be expensive. It is often economic to install an off-grid system for people living a distance from the grid. However when the grid is available, going off-grid is probably not economic at this stage.


The intention of this page is to broaden your knowledge of what is involved, approximate costs and existing technologies currently in use.



Solar PV panels are by far the most common generation source. Solar panels are easily installed, last a very long time (upwards of 20 years), very low maintenance and can be installed anywhere with a decent northerly view (Southern hemisphere) or southerly view (northern hemisphere) including urban areas.

However they do not produce a high output for the area and cost involved. They are only useful when the sun is out (cloudy conditions produce very low output).



If available this option is ideal. With a reliable water source and good head then a house can easily be powered by hydro. However few locations are suited to using hydro which limits its use.



Most locations have wind at some stage. However access to a turbulent free air flow is important. Turbines are suited to hills and areas away from buildings and trees. Generally wind turbines are not installed in urban areas due to noise and visual pollution. Turbines have to be able to withstand storms. Additionally wind is not always reliable (less than the sun) so large battery storage or the grid is required. Wind speed and power output is related cubically. So low winds produce very little output compared to wind speed slightly higher. So what you find is huge amounts of power available in storms and little in daily breezes.



The following information gives a rough cost to install a system to an existing house.


  The Following prices are all in NZD