“Do you know that the solar energy that strikes the earth’s surface in one hour is enough to feed the world’s current electricity needs for one year? Why haven’t we gone solar already?” asked John Cleese in the film, The Power of the Sun, which screened at U of T on Tuesday.
The film is Nobel Prize laureate Walter Kohn’s attempt to address the frustration he feels living with the current energy situation in the United States. Speaking at the film’s screening, Kohn said he was disheartened at the Bush administration’s withdrawal of funding for alternative energy source development and the light-handed approach to conservation among Bush’s advisors. Kohn designed the movie as a “scientific morality tale” to educate the general public and policy-makers about solar energy.
According to Kohn, if we keep energy consumption at today’s levels, the U.S. Department of Energy estimates that, in 20 to 40 years, oil reserves will be gone, or at the point where extracting it will no longer be economically viable. By then, nuclear, solar, wind, and other alternative energies will become commercially competitive.
Some industry executives think the crossover point will be as close as 10 years away, as new advances in solar technology may make solar alternatives cheaper and more efficient. Today, silicon-based solar cells offer conversion efficiencies-from captured sunlight to electricity-of six per cent to 40 per cent, but the higher range is only achieved in the lab. The most efficient technologies, at 34 or 35 per cent efficiency, are used in space applications, where durability and reliability, not cost, are the main concerns.
Richard Swanson, president of SunPower Corporation, said the solar cell industry is growing 30 to 35 per cent per year and today represents a $7 billion industry worldwide. This may be small compared to other energy industries, but solar power is becoming increasingly important as the viability of oil-based energy solutions wanes. Kohn said he expects solar energy to contribute 25 to 35 per cent of the total energy globally consumed within 50 years’ time.
Balancing the energy efficiency and manufacturing cost of solar cells is a crucial step to making solar energy an option for homeowners and small businesses, and a process for making the cells out of plastic polymers may be a revolutionary advance. Alan Heeger, winner of the 2000 Nobel Prize for chemistry and a speaker in The Power of the Sun, makes polymer-based solar cells with efficiencies of five per cent. Other possible mass-production technologies include a semiconducting polymer that can be printed like ink on a flexible surface. Heeger is eager to fine-tune the plastic polymer solar cell to 10 per cent efficiency, which would make it almost as efficient as silicon-based solar cells used today, but less expensive to produce.
Kohn’s film features success stories of solar power all over the world, in developed and developing countries. Already, a number of private homeowners, farms, recreation parks and recycling centres are powered entirely or partially by solar power or have begun selling energy back to power companies. In Kenya, an equitorial country perfectly positioned for sunlight capture, small panels atop houses can provide indoor lighting after sunset. In one remarkable story in East Africa, a solar panel powers a fridge carrying UNICEF medicines during cross-country trips on the back of a camel.
“No one seriously suggests solar energy alone will transform the world’s energy picture,” cautions narrator Cleese. “It needs to be part of a whole package of renewable energy sources.”
Windmills in California, million-dollar solar installations in Germany, and solar rooftops in Japan are making differences in these areas, but the great majority of the world balks at the cost of solar energy, which is about double the cost of fossil fuel energy.
But for U of T department of chemistry and physics professor R.J. Dwayne Miller, cost calculations need to consider the environmental impact of extracting, refining, transporting and using fossil fuels. Solar panels minimize environmental costs while, according to Kohn, lasting upwards of 25 years. Only 10 per cent of the total energy a solar panel can harvest in its lifetime can be attributed to the cost of producing and disposing of that solar panel.
Clearly, the film’s take-home message is to practice energy conservation, invest in alternative energy development, and-cheesy as it sounds-that we all can and should help change the current state of global energy consumption. The optimistic and scientifically-informative film ends with a personal appeal from John Cleese to support energy reform. But after the film’s hard facts, expert testimony and scientific demonstrations, choosing alternative power shouldn’t seem like a sentimental choice, but the only reasonable option.
