23
4. To treat your water.
If you live in a country where your local water supply is unsafe, you can use the sun to disinfect water by filtering muddy water, filling plastic pop bottles and leaving them out in the sun for at least six hours. The Sun’s ultraviolet rays will kill any bacteria or organisms, and can reduce diarrhea diseases from taking hold. If you live by the sea, solar PV can be used to power a desalination plant.
5. To power your car.
Imaging driving, powered only by the sun. Driving the new Nissan Leaf 16,000 kilometre a year, for instance, will use 2,000 kWh of electricity. A two–kilowatt PV system on your roof will generate 2,200 kWh a year, and cost you $16,000. On a 20 year mortgage, that’s $25 A week, or $3.50 A Day-Lewis and once you’ve paid for the solar panel, the energy is free.
6. It won’t be long before most roofs are covered with solar panels. Thirty years ago, solar photovoltaic (PV) cost $100 A watt.; today the average cost of an installed PV system is $3.48 A watt. A five-year kilowatt system, generating 5,500 kWh a year, will cost $ 40,000 across Canada, except in Ontario, where the Green Energy Act provides generous incentives. When the per-watt cost falls to $1, we’ll see solar PV everywhere.
24
7. To design your home.
When an architect design a passive solar home, they make the most of the Sun’s light and heat by using South facing windows, maximizing insulation on the north, and creating a thermal mass to store solar heat. These steps can reduce heating needs by 50 per cent. The architect also works to maximise the Sun’s natural light, reducing the need for artificial lightning. And if building your own house isn’t an option, it is possible to retrofit your house to use the Sun’s energy more inefficiently. This can involve installing more energy-efficient windows and shading any South facing windows.
8. To heat your home.
Solar thermal energy heats 52 homes in the Drake Landing Solar Community in Okotoks, Alberta, even in the dark and cold winter. Eight hundred solar hot water panels gather sunlight on garage roofs and store the excess energy underground. In winter, it is pumped back, meeting over 90 per cent of the community’s heating needs. In Europe, the solar thermal industry aims to heat 50 per cent of all buildings using a similar approach by 2030.
