PV prices are dropping fast. Some people don't have natural gas and use electric hot water tanks. To save on the cost of grid power, which can be over 20 cents per kWhr in some places, a hot water tank could be converted to use DC power straight from the solar panels. This saves on the cost of an inverter, and a lot of paperwork to hook up to the grid.
Some numbers: A 220W panel costs about $600, and will produce an average of 3.5 hours per day of full power in Toronto, and should last about 25 years. Over that time, the panel will make 3.5hrs x 0.22kW x 365.25days in a year x 25 years = 7031 kWhr. Dividing the cost by that amount gives $0.085. How many people only pay 8.5 cents per kWhr for power at their home?
If you normally pay 20 cents per kWhr, and this system saves you 11.5 cents per kwhr, over 25 years it will save $808.56. Given McGuinty's promise to raise power prices by 40% in the next five years, I wonder how many people will *not* have solar panels by then.