Alternative ways of generating electric power can reduce grid usage, and provide self-sufficiency in remote areas. In addition, renewable energy generation is possible for residential houses, and excess energy can even be sold back to the grid. A very brief outline of options is presented below – more information is available at the government’s Energywise site.
A diesel generator is the traditional solution for off-grid energy. It is the least environmentally-friendly method of generation, but is the most reliable and convenient. Where a constant supply of electricity is needed, this may be the only option – or may be a backup option for a wind generation system.
Combined Heat and Power (CHP)
These systems produce both heat and electricity, and thus are a versatile option for off-grid locations. They are usually fuelled by fossil fuels such as gas – one example is the Whispergen system.
Solar electricity is generated by photovoltaic cells, usually arranged in panels and placed on a roof to catch the most sun. Solar cells can provide enough energy for a whole house in summer – and excess electricity can be sold back to the grid. In winter however, some grid electricity is likely to be required. Aspects to be taken into account with these systems are the intended use, geographic location of the house, orientation to the sun, and costs (including payback time).
New Zealand is ideal for wind generation – we sit in the ‘roaring forties’ and many part of the country have a reliably steady wind flow. Small-scale wind turbines are commercially available, and are an excellent choice for windy and remote locations. Turbines can charge batteries when it is windy, and the power can be used on-demand later. Some examples are available through Pacific Wind Energy.
Micro hydro systems are suitable for properties that have a stream, and a big enough change in altitude. Water from the stream runs downhill through pipes into a generator. This type of system can provide a steady stream of renewable, clean energy. Two examples in New Zealand are from Electric Systems and EcoInnovation.