Monday 11 September 2006

Solar power can be pricey

Toronto Star
Sep. 7, 2006

If solar energy can run everything from parking meters to pay phones and spacecraft to car battery chargers, why can't it power your home? And while we're at it, why can't we all harness the wind as an energy source? It's free, too.

The reality is that renewable energy sources work but are among the most expensive forms of power on the market today when the cost of buying and installing the equipment is factored in.

Still, solar and wind power are being used successfully every day: The City of Toronto has hundreds of solar-powered parking meters and bus shelters that light up at night from the sun collected during the day. And the giant turbine at the Ex reminds us wind is a big part of the future.

Simply described, wind turbines gather blowing air, which pushes propeller-type blades that turn a shaft wrapped in copper wire and suspended in a magnetic field to excite electrons and thus create electricity.

While the wind is free, the necessary turbines and related accessories are far from it.
This spring Canadian Tire launched a line of wind turbines and solar panels aimed at those who don't have hydro lines. Wind turbines start at $800 for a 400-watt model and go up to $3,000 for a 950-watt version, which features a 2.2-metre propeller and must be mounted at least nine metres off the ground. The retailer also has 80- and 120-watt photovoltaic solar panels, which can be combined and mounted on roofs.

"They're intended for the off-grid user — cottages and farms," says Greg Lobb, a manager specializing in energy at Canadian Tire. For now, electricity users are scared away from new energy technologies because of the high price to buy wind turbines, solar panels and related equipment when the cost of conventional power is so comparatively low in North America. People are slow to embrace new and developing technologies, especially if they're seen as unwieldy.

The wind turbines or solar panels themselves represent only about half the initial investment if you want to make use of these alternative energy sources. You'll also need a system of batteries to store power, a converter to harness 12-volt battery power at 120 volts and, if you're on the grid, technology to know when to draw power and when to run on just the in-house generators. And to take advantage of the Ontario government's pledge to buy solar power at a whopping 42 cents a kilowatt-hour you'll need a special meter.

Such systems are aimed at those who have no other accessible power source, where it is too pricey to bring in a power line. While thermal solar using panels to heat up potable water for pools, showers or laundry is somewhat popular, photovoltaic, which converts sunlight into electricity, has not caught on in the same way, says Rob McMonagle, executive director of the Canadian Solar Industries Association. There are a number of different technologies that convert sunlight into electricity. The most common uses a silicon semi-conductor, which releases electrons when the sun strikes it.

While the sun can create up to 1,000 watts of energy per square metre, most photovoltaic cells today can convert only up to 20 per cent of it to power.

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