Geo News

Off the grid

Domestic lighting and heating come at a cost, and most people are resigned to rising energy prices. But bigger bills—and high connection fees for people building in out-of-the-way locations—are forcing many people to seek an alternative to drawing power from the national grid. From the backblocks to city blocks, free thinkers are seeking free power; by harnessing wind and sun, they are living off the grid. Two Otago couples have cut the umbilical power cord in different ways. Ken and Sue McDowell were in their mid-20s when they bought a 2.5-hectare hillside section at Portobello on Otago Peninsula, a short drive from Dunedin. When they enquired about getting power connected, they were quoted more than $20,000. "If we had known that, we would not have bought the place," admits Ken. "We had to look at alternative ways to get power without too many changes to our lifestyle. It was going to be a big learning experience." The McDowells planned an environmentally friendly house, using recycled timber and earth bricks they made themselves, but otherwise they hoped for a normal home. Alternative power had to be unobtrusive. Prevailing northerlies and their hillside location seemed to point to a wind-power solution, and they ended up choosing a custom installation designed by a Dunedin company. Their 11-metre-high windmill, positioned 60 metres from the house, generates up to 1 kW of electricity at 24 volts of direct current, charging a bank of six deep-cycle six-volt batteries designed to handle regular charging and discharging. An inverter converts the stored power to a regular 240-volt supply of alternating current which feeds the McDowells' conventionally-wired house. In addition, solar power is gathered on the roof by two kinds of solar collectors. One is made up of light-sensitive photovoltaic cells which help to charge the batteries. The other is a set of solar panels which absorb heat from the sun and transfer it to the hot-water cylinder. The cylinder also contains a 24-volt heating element which is powered directly from the windmill once the battery bank is fully charged. A wetback coal range provides yet more heat for the water, heats the house and supplements the McDowells' gas cooker. They run most standard household appliances, from television and VCR to microwave oven. Only the fridge-freezer is out of the ordinary, running on 24 volts to ensure a permanent supply. The McDowells admit that they have had to make some changes to their lifestyle, but they have been far from onerous. Says Sue: "You have to think about the best time to do the washing, because it takes a lot of power. It may seem trivial, but it's important if you are busy. Only in winter do we really have to be careful." A diesel generator is used as a last resort if all else fails, or if the McDowells plan a day of power-hungry activities—several loads of washing, drying, ironing, vacuuming or using power tools. "When you live with normal electricity you don't think about what you're using," says Ken. "It's easy. Nothing beats the flick of a switch. Now we have to be aware of what's happening when we flick that switch."dunetional grid, but it is cheap to maintain, and Ken reckons they will recoup the extra expenditure within four years: "We can live like this for the rest of our lives and bring up a family like everybody else in town. And we'll never have to worry about finding money for power bills." Mark Ayre and Mary Chaffey, living in a remote country hideaway near Hawea, in Central Otago, have solved their energy needs in a slightly different way. The couple moved on to their 50 ha block with a VW Kombi van and a tent while they built an easy-on-the­environment octagonal wooden house. During the building process they upgraded their temporary accommodation to a bus with a solar panel, and that was the beginning of the system which now powers their completed home overlooking a picturesque bend in the Hawea River. Unlike the McDowells, Mark and Mary have an obviously alternative home. It was built by stacking interlocking (200 mm x 100 mm) Oregon beams and chain-sawing the joints to fit. Windows and doors were sawn out of the giant 3-D jigsaw when it was finished. Water heating for the house comes from solar panels in the summer and a modified wood-burner during winter. Cooking is by gas. As the house grew over the years, power require­ments increased, and more photovoltaic solar panels were purchased. They generate a 12-volt direct current which charges 24 deep-cycle, two-volt batter­ies. An inverter supplies 230-volt alternating current to the house when it is needed, although many appliances run off the 12-volt direct current. "In the summer we produce so much power that we could put surplus into the grid," says Mary. "We would like to be able to do that and build up credit for the four weeks of the year when we would like to draw it out." Although Central Otago has many hours of winter sun, for a few weeks around the shortest day the solar disc often struggles to keep up with demand. Mark and Mary, both in their 30s, say that their system has been put together over years of trial and error and is still evolving. It owes more to Kiwi ingenuity, they say, than to off-the-shelf design. With more money, they could improve the system and eliminate the midwinter shortfall. For them, finance has been a big consideration. Connecting to the grid (on average $30,000 per kilome­tre) would have cost $40,000 and was never an option—it would have doubled the price of the original house. Fven now, Mark and Mary's do-it-yourself system has cost only about a quarter of the connection fee—and their house has won environ­mental awards sponsored by the Otago Regional Council and ECNZ. Now, Mark is putting his knowledge to use as an energy consultant and is experimenting with wind power. Whether capturing Central Otago's sun or Dunedin's coastal wind, these four New Zealanders are enjoying what many people dream of: the satisfaction of being inde­pendent of power compa­nies, at little cost to their lifestyles.

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