HARNESSING THE SUN FUELS EARTH’S BEST HOPE

Courtesy of Medill   The sun promises the most substantial source of renewable energy for the earth.
Courtesy of Medill
The sun promises the most substantial source of renewable energy for the earth.

by Kristen Minogue
Nov 11, 2009

The world needs a solar revolution to enter the era of energy sustainability and avert the floods, droughts and crop losses expected to result from global warming, according to one scientist.

But politics, economics and technical hurdles ensure the world will run on fossil fuels for the near future. 

Sources of renewable energy abound, ranging from wind to hydro to biofuels. But only one can fuel the entire planet and allow everyone the same standard of living that Americans enjoy, said University of Chicago climate scientist Elisabeth Moyer. And that is the sun. 

“Getting it straight from the sun is really the best way,” Moyer said.

Radiating the power of two light bulbs per square meter of land, the sun could provide enough energy in a minute to fuel the planet for a year. The trick is to harness and store that energy. 

Moyer, who teaches climate and energy, broke down the realities of supply from most of the major alternative energies at the recent Climate Change Symposium at Northwestern University. Even with the most unrealistically optimistic assumptions about catching all the rainfall or harnessing wind at just the right speed, hydroelectric and wind power would barely make a dent in world energy needs.

Biofuels pose the problem of using cropland on a hungry planet for energy production.

Moyer did not include nuclear energy in her discussion. She said after the conference that she believes the industry will take years to revamp after the halt in 1979 when the Three Mile Island nuclear plant accident melted half the fuel in a reactor. The incident ended plans for new U.S. plants even though no one was injured and only small amounts of radiation escaped.  

But the U.S. government recently launched a plan to add 100 new nuclear reactors, nearly doubling the current number. And nuclear continues to supply 20 percent of the nation’s electricity and 8 percent of its total energy, surpassing all the current energy obtained from renewable power sources.  

However, in the roaring energy market of the 21st century, fossil fuels are still drowning out the cleaner alternatives.

With nuclear providing 8 percent of our energy, renewable resources including biofuels provided 7.3 percent of the total energy consumed in the U.S. in 2008. But fossil fuels still accounted for 85 percent. 

And of the 7 percent derived from renewables, only one percent of that came from solar power. 

Two major obstacles stand between the sun and a less carbon-infested planet. Simple cost is the first and storage is the second.

Assuming a 40-year lifespan, the price of electricity from a solar thermal system costs double that of coal-generated electricity. The price more than quadruples if the system only lasts for 20 years and is even more expensive for power from photovoltaics. 

Past experience and the laws of development indicate that as time passes, people get smarter and technology gets cheaper. But in the meantime, coal remains an incredibly inexpensive and reassuringly domestic energy source. And with the infrastructure that is in place, the cost of replacing it could amount to tens of trillions of dollars, estimates Jack Lewnard of the Gas Technology Institute. 

Lewnard said he believes the same rules apply to developing countries, that stand little chance of bypassing the carbon phase if they want to enhance their economies. 

“I can’t say that they’ll skip,” he said, speaking at an NU energy conference two days after the climate change symposium. “They may be able to make some dents in things, but right now the path for industrialization is still on the fossil path.”

If the price of solar doesn’t go down, the government should step in and raise the price of fossil fuels to close the gap, said Northwestern economics professor Mark Witte.

“We just have to make CO2 production so expensive that we don’t do it,” he said.

Witte said he prefers a carbon tax to a cap-and-trade strategy for its simplicity and transparency. But he said he would support whichever method gets the job done faster.

One need that will add to the cost is carbon sequestration, removing and storing CO2 from fossil fuels to substantially reduce greenhouse gas production associated with global warming.

Finding a way to economically store the light from the sun after it gets dark is another challenge. Because unlike the market for energy, the Earth’s rotation away from the sun every night is a given.


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