Solar Power

The Sun, after all, powers our planet. Yes, there is also geothermal energy contained within the Earth, but such crucial forces and processes as winds, ocean currents, and photosynthesis are all powered by the heating effect of Sol. No one disputes the fact that without the Sun, life on Earth would cease to exist.

So, since the Sun provides so much “free energy,” why not use it more to our advantage? Part of the answer, up until now, may lie in the fact that sunlight cannot easily be contained and sold. It’s not as easy for big corporations to make money from, so therefore they haven’t made a big investment in it. Also, solar power cells have never been particularly efficient. And they’ve often been just plain ugly, too.

But since few can dispute the fact that fossil fuel supplies must eventually run out, and that large segments of the remaining reserves lie beneath countries that are at least potentially unstable in the political sense, the future of solar energy is becoming increasingly bright (so to speak).

One possible use of solar power in the future may be to construct space satellites which would gather solar energy and transfer it to collection points on the Earth’s surface via concentrated microwave beams. Power companies would then distribute the electricity, thus still making profits and therefore having an incentive to invest in this technology.

But here in the “now,” more and more solar options are appearing or being developed. For example, a company known as XsunX has developed solar panels on semi-transparent, flexible plastic film. While not as efficient as traditional solar panels (6% energy conversion compared to 15% with silicon cells), they can easily be applied to the windows on skyscrapers, for example, harnessing vast unused surface areas for solar collection. (See Business 2.0, Vol.6, No. 11, December 2005, p. 36, article by Meredith Sadin).

And solar shingles are now appearing that will enable a house’s entire roof to be a solar energy collector (without having an unusual appearance). Known as BIPVs (building-integrated photovoltaics), these shingles (which can be made from materials ranging from metal to asphalt) currently cost about $60 per square foot, compared to about $1 per square foot for ordinary asphalt shingles. But they then provide “free” electricity to the dwelling on sunny days, even enabling the owner to sell the excess back to the power company in states that allow it. Think of that – your electrical meter running backwards! And on top of that, the U.S. Federal Government also is giving tax credits to help offset the cost of obtaining such a system. (See This Old House, June 2006, No. 99, pp. 61-62, article by Keith Randolfi).

Even more exciting is the 1600-foot-tall “solar tower” being proposed by the Australian company EnviroMission. Projecting from the center of a two-mile diameter transparent canopy only eight feet off the ground at the outer edge and 50 to 60 feet at the tower rim, the 260-foot-diameter tower will funnel solar-heated air up and out through its top. In the process, the rising air will have to travel through power-generating turbines. And at night, heat from saltwater ponds on the periphery would be released into the tower, continuing to use the sun’s energy to generate electricity.

In a sunny place like India, for example, a tower such as this could generate 50 megawatts, enough electricity to support a city of 250,000 people. And this could be done cleanly, without relying on nuclear or fossil fuel energy. (See Business 2.0, Vol. 7, No. 7, August 2006, pp. 94-102, article by Todd Woody).

Perhaps in the future, solar towers will become as ubiquitous as water towers, with every town having its own.

And as a small-scale example of what can be done with the power of the sun, when it comes to cooking the food you eat, why not try a solar oven on sunny days? Cooking your meal using the free power of the sun can give you a satisfying feeling and be fun at the same time. Many solar ovens are commercially available, and while not always inexpensive to purchase, they should last almost indefinitely, cooking meals not only without electricity, but also with no maintenance other than cleaning. There are even hybrid solar-electric ovens that can be used whether the sun is out or not.

And solar ovens can provide tremendous benefits in rural areas of developing countries by reducing or eliminating the need for people to cut down trees for cooking fuel (although they may still cut them down for heating, nighttime cooking or other purposes). It’s a great way to reduce deforestation. Also, the ovens may be used to pasteurize drinking water.

Lastly, solar ovens offer numerous other advantages – they cook food evenly (albeit slowly, rather like a crock pot), making it very hard to burn it, and also do not require that food be stirred during cooking. In addition, they caramelize natural sugars contained in vegetables, giving them improved flavor. (See solarovens.org).

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