Ten ways to use the sun’s energy
1. To dry your clothes
The sun has gone to a lot of trouble to send us its energy, so appreciate it! The heat and light on your face was on the surface of the sun eight minutes and nineteen seconds ago. So as a minimum, use it to dry your clothes. Since the sun is a giant nuclear reactor, tell your friends you have a nuclear-powered clothes dryer.
2. To grow your food
Take away the sun, and what can you grow? Maybe marijuana under grow lights? With just soil and sunlight you can grow tomatoes, peppers, apples, raspberries, salad greens and more. Build a solar greenhouse that stores the sun’s heat in earth or concrete, a double-skinned insulated greenhouse, or a soap bubble greenhouse and you can grow food even during a cold Canadian winter.
3. To heat your water
Seventy million Chinese households use the sun to heat their water so why don’t we? You can use evacuated tubes or a flat plate to gather the sun’s heat. For an investment of around $6,800, these mechanisms will provide 100 per cent of your hot water in summer, maybe 40 per cent in winter. There are grants available to help in many provinces. See www.solarbc.ca.
4. To treat your water
If you live in a tropical country, and your local water supply is unsafe, you can use the sun to disinfect water by filling plastic pet bottles and leaving them in the sun for at least six hours. The sun’s ultraviolet rays will kill any bacteria or organisms. If you live by the sea, you can use solar PV to power a desalination plant. See www.sodis.ch.
5. To generate your electricity
It won’t be long before most roofs are covered with solar panels. Thirty years ago, solar photovoltaics (PV) cost $100 a watt; today it’s down to $4. Double that for the installed cost. A five-kilowatt system, generating 5,500 kwh a year, will cost $40,000, 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.
6. To power your car
Imagine driving, powered only by the sun. Driving the new Nissan Leaf EV 16,000 kilometres 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—and once you’ve paid for the solar panel, the energy is free.
7. To design your home
When an architect designs a passive solar home, she makes 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. She also works to maximize the sun’s natural light, reducing the need for artificial lighting. See www.buildgreen.ca.
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 of 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 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. See www.dlsc.ca.
9. To cook your food
There are various kinds of solar cookers: some use a reflective solar box, others a parabolic disc. In developing nations, solar cooking lifts the burden of walking miles to strip trees for firewood. In summer, solar cookers work in Canada too, whether you buy or make one. See www.solarcooking.org. You can also make your own solar dryer for the fruit and veg in your garden. See www.geopathfinder.com/9473.html.
10. To power the world
Every day, the sun radiates a thousand times more heat onto the world’s deserts than we use. Solar thermal technology, using parabolic dishes or solar towers, can convert that energy into steam, and then electricity. We could meet the entire world’s energy needs by using just five per cent of Texas for solar thermal energy. So who needs oil and oil spills? See www.100milesofmirrors.com.
Reprinted with the permission of Corporate Knights.
Guy Dauncey is a speaker, author and eco-futurist who works to develop a positive vision of a sustainable future, and to translate that vision into action. He is founder of the BC Sustainable Energy Association, and author or co-author of nine books, including the award-winning The Climate Challenge: 101 Solutions to Global Warming. He is currently completing a new book titled Earth’s Secret: A Journey to the Future, set in Vancouver in the year 2032, when it has become the greenest city in the world. His website is www.earthfuture.com.