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Photovoltaic panels

SIXTEEN photovoltaic panels give us about one kilowatt of solar power during peak sunny periods. That's considerably less than the amount of electricity consumed by the typical North American household, but with efficient lights and appliances, conservation, and a relatively simple lifestyle, we have an adequate power supply for both home and office.

(We also have a propane-powered refrigerator, which reduces our electricity demand, but is still reliant on a fossil fuel. We are looking for ways to refrigerate with renewable energy.)

The solar electricity is stored in 12 deep-cycle lead-acid batteries, similar to those used to power electric golf carts. We have direct-current (DC) circuits for many of our compact fluorescent lights. We also have an inverter that provides alternating current (AC) power for office equipment, home appliances, and our water pump.

We adjust the angle of the panels several times a year, according to the changing tilt of the earth on its axis through the seasons, which increases the photovoltaic efficiency. There are ingenious, but expensive, mechanisms on the market that can make the panels track the course of the sun during the day as well, further increasing efficiency, but we figure that we could get the same result for less money by just adding more non-moving PV panels.

We hope that before long we will have some kind of wind turbine tied into our system, because it could generate electricity during cloudy, windy weather, when the PV panels aren't very productive. But that's a very expensive proposition that we need to weigh carefully. •

I have no doubt that we will be successful in harnessing the sun's energy... If sunbeams were weapons of war, we would have had solar energy centuries ago.

—Sir George Porter