August 1, 2008

Prospects for concentrated solar power burn bright

Construction Corner

Korky Koroluk

Sometimes it seems as though solar power has been the next big thing on the energy horizon for decades, always on the verge of a breakthrough it never achieves.

After all, what could make more sense than tapping into the sun — the biggest, steadiest source of energy we’re ever going to have? But it hasn’t been easy.

Now, though, a new concept called concentrating solar power (CSP) has emerged. I’ve mentioned it before: sunlight concentrated by mirrors. And its advocates are calling it the most important form of carbon-free power in the 21st Century.

That might be true, although I’ve noticed that the people making such extravagant claims all seem to have something to sell.

The knock on solar power has long been the cost. Usually thought of as being far too expensive to be a viable source of power, the idea of solar power is now benefiting from technological innovation spurred by the rising cost of fossil fuels and the environmental concerns that arise as a result of their use.

A team of scientists from the Massachusetts Institute of Technology has come up with a new way to concentrate solar rays, a way that might reduce the cost of solar panels.

Their work raises the possibility of using ordinary domestic windows to generate electricity without structural alterations. It’s a great-sounding idea, even though no one has yet worked out how much it would cost to convert a home into a solar-powered generator of electricity. Nor has anyone figured out how use of the new technology might affect energy supply and cost factors in commercial construction.

The idea MIT’s scientists have come up with is something they call a “solar concentrator.” It’s made of a film of molecules that can be coated onto glass window panes. It’s so thin it lets light pass through the window.

What really sets this development apart, though, is that the researchers have found a way to gather light over the entire window area and concentrate it at the edges.

Commercial solar concentrators already exist, of course, although their share of the energy market is miniscule. They all rely on systems that enable the array of concentrating mirrors to track the sun as it moves across the sky. These systems generate the highest optical intensities, but they are expensive and can be difficult to maintain.

The system that concentrates the light around the window edges means there is no need to have a system that follows the sun. That will reduce the cost. A lot.

Another intriguing possibility exists. The ultra-thin coating can be applied to other surfaces as well as the glass in windows, so could it be “painted” onto a building’s cladding, perhaps? We already have solar cells printed onto steel cladding panels, so that part of the idea has been tested. The MIT coating could be a next step.

I must emphasize, though, that this is not yet a commercial product, and it may be a while before it is. But it is, I believe, an important part of the forces that are at last making solar power look feasible. Earlier attempts to commercialize solar power were all derailed by abundant, cheap oil.

Things have changed, though, and there have been so many technological innovations that solar energy may soon be able to compete in cost with other forms of energy.

As with any evolving technology, many people underestimate the scale of the problems faced. That includes the cost of the technology, of course, but also the challenge of manufacturing and deploying what amounts to a whole new energy infrastructure.

But stop and think for a moment about the huge opportunity that exists for any company that manages to get the business of solar energy right.

We’re entering an era in which the opportunities for innovation are greater than ever, and those innovations will bring with them economic growth in all sectors, including construction.

Korky Koroluk is an Ottawa-based freelance writer. Send comments to editor@dailycommercialnews.com.

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