KEY POINTS:
Charmaine Watts hasn't had a power bill for eight years.
Her family of two adults and three children are one of hundreds around the country generating their own electricity.
With power prices on the rise, the $20,000 the Watts spent installing solar panels, a small wind turbine, storage batteries and wiring is starting to look like a good investment.
"I don't need to worry about power cuts," said Ms Watts. "It's just like a normal house. I flick the switch on my computer or my DVD player and away I go."
Watts is the head of the Sustainable Electricity Association of New Zealand, a group representing small-scale wind, hydro and solar power generators. Nobody knows exactly how many families generate their own power, but together it's thought they make between 5 and 6 megawatts of power a year - a drop in the bucket when measured against Meridian's planned West Wind wind farm near Wellington and its 142 megawatt production.
Watts says solar panels lasting between 25 to 30 years cost $25,000 , making them a good option even for city dwellers.
"Anyone with a roof has the potential to make their own electricity."
Solar panel dealer Mike Prior said the photovoltaic panels (the technology that generates electricity from the sun) were still too expensive for most people, even with prices falling all the time.
"A lot of people like the idea, but they run and hide when you tell them the cost," he said. "Most people spend about $40,000 installing a solar panel system, and you can buy a lot of electricity for that amount."
Mr Prior said home generation was a good option for people who lived away from the national power grid or who needed only small amounts of electricity. A basic system to power lights and hot water could cost as little as $5000.
For anyone living more than 500m from national power supply lines, installing a power supply worked out cheaper than connecting to the grid.
Mr Prior said solar generation would be affordable for most people only if the Government followed Germany and Australia and subsidised renewable power. "The market exploded in Germany. Manufacturers couldn't make enough panels," said Mr Prior. "The trouble here is the Government gets a return from state-owned renewable generators like Meridian Energy, so there's not much incentive to provide subsidies."
Ms Watts said the Government could do more to lower the barriers for home generators - like making it easier for people to sell their excess power back to the national grid. But for her family home generation was about more than saving money.
"We've saved something like 10,000 tonnes in carbon dioxide since 2000 by using natural, renewable energy."
There are drawbacks to self-sufficiency. Unlike the rest of the country, which has months to cut back on power when lake levels are low, the Watts have only five days worth of power stored.
By using LPG for cooking and a wood burner for hot water, the family live on between 500 and 1000 kilowatt hours of electricity a year, compared with between 8000 and 12,000 for the average family. When sun and wind are in short supply, they cut down on TV and read instead. "We have to ration the use of the hair straighteners," says Ms Watts, who has two teenage daughters.
"It took us a while to get used to budgeting our energy use, but we haven't had to hire a back-up generator for the last two years."
* SMALL N' POWERFUL
- The Sustainable Electricity Association of New Zealand (SEANZ), headed by home power generator Charmaine Watts, is working with the Government to find out just how many New Zealand families generate their own power.
- Most families who make their own power live away from national power supply lines in rural areas. For example, the 800 residents of Great Barrier Island in the Hauraki Gulf have no choice but to supply their own power as they have no access to the national grid.
- Urban dwellers usually have to rely on roof-mounted photovoltaic panels, which generate electricity from the sun, to make power. Rural families may be able to use a combination of sun and wind or hydro power, depending on what resources they have on their property.
- In a typical scenario, power generated from a small hydro dam or a combination of a small wind turbine and solar panels is stored in a bank of deep cycle batteries in a shed next to the house. An inverter then converts the deep cycle battery power into AC power that can be used to run standard household appliances.
