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If it strikes you as odd that, even when it's really hot outside, oil and coal are burned to generate power to produce residential hot water, well, you're not alone. But that is how most homeowners get hot water: fossil fuel-fired power plants emit planet-warming greenhouse gases to generate the power that runs our hot water heaters.

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Mounted side-by-side on a roof are two types of solar water heat collectors: flat plate and evacuated tube.

If that seems counterintuitive, isn't it then intuitive to instead use some of that free heat from the sun to heat our water?

Solar hot water systems

Solar hot water heating has been around for a long time. Two types of technology are most common, plate collectors and evacuated tube systems.

Plate collectors are flat, glass-covered panels that have fluid-filled tubes zigzagging back and forth through them. They are what most of us envision when we think of solar panels. One of the leading manufacturers of such systems is a Dartmouth company, Thermo Dynamics (www.thermo-dynamics.com).

Evacuated tube systems are similar, except that their fluid-filled tubes run through glass vacuum tubes for improved efficiency.

In both systems, the fluid in the tubes - a non-toxic antifreeze - is heated by the sun and then pumped indoors where it heats the water.

Because solar systems are typically designed to work in conjunction with existing electric hot water heaters, you never have to worry about running out of hot water on cold or cloudy days. The hotter or sunnier it is, the more heat you get for free from the sun and the less you need to buy from your power utility.

The pros and cons of solar

The biggest advantage of solar hot water is energy savings. It is estimated that a solar hot water system can reduce a household's water heating costs by up to 65 per cent. Hot water heating represents 20 per cent of a typical home's energy consumption, so the savings can be significant.

As well, since much of New Brunswick's power is derived from fossil fuels, every solar hot water system installed lowers our province's carbon footprint and our dependence on imported fuel.

Solar hot water isn't totally free though. Unlike a rented electric hot water heater, solar systems do require a significant up-front investment, and there aren't a lot of qualified installers around. Still, they do pay for themselves in the medium to long term. The higher power rates go, the shorter the payback period.

As well, the sun doesn't shine with equal intensity all year, so solar panels don't heat water as much in winter as they do in summer. Still, even in January, they can capture more of the sun's energy than you'd expect.

Many countries clearly understand the potential of solar energy. In Spain, Portugal and Israel, all new buildings are required to have solar hot water heating systems. About 200,000 systems were installed in Germany in 2008 (and most of Germany receives less sunlight than most of New Brunswick). In over 50 countries, homeowners who install solar are eligible for incentives.

In New Bruswick, the cash incentives for solar hot water systems are very worthwhile. Homeowners are eligible for a grant of 20 per cent of system costs or an interest-free loan from Efficiency NB (conditions apply - contact Efficiency NB for details). And if you had an energy evaluation booked under the now-discontinued federal EcoEnergy program before March 31, 2010, you could be eligible for an additional $1,250 grant from the feds (again, conditions apply - contact EcoEnergy for details).

Life with solar

Solar hot water was installed on our home last month, and the early performance is impressive: the system has been producing hotter water than the electric heater did. In fact, it's providing so much hot water that last week I turned the electric hot water heater off, just to see if the solar system can do it alone - and so far it has, comfortably.

Maybe you're looking for a way to lower your power bill and your carbon footprint; maybe you just enjoy the prospect of free energy. Either way, look up - and take advantage of that free, limitless sunshine to heat your hot water.

To find suppliers and installers, check your yellow pages or visit www.allthingsefficient.ca or www.renewablesnb.ca.

Carl Duivenvoorden www.changeyourcorner.com is a speaker, writer and green consultant living in Upper Kingsclear. His column runs every other Monday.