Brother, Can You Spare 22 Terawatts?

Big ideas for the future of energy

Ronald Bailey | November 24, 2006

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So where will the extra energy come from? Relying on figures from the World Energy Assessmentby the United Nations Development Program, Nocera looks at the maximum amounts of power that various non-fossil fuel sources might supply. Biomass could supply 7-10 TW of energy, but that is the equivalent of harvesting all current crops solely for energy. Nuclear could produce 8 TW which implies building 8000 new reactors over the 45 years at a rate of one new plant every two days. Wind would generate 2.1 TW if every site on the globe with class 3 winds or greater were occupied with windmills. Winds at a class 3 siteblow at 11.5 miles per hour at 33 feet above the ground. And hydro-power could produce 0.7-2 TW if dams were placed on every untapped river on the earth. Nocera concludes, "The message is clear. The additional energy we need in 2050 over the current 13.5 TW base, is simply not attainable from long discussed sources—the global appetite for energy is simply too great."

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Burning coal, gas, and oil could fuel the world in 2050, but the carbon dioxide produced by these fossil fuels would have somehow to be captured and sequestered (CCS) underground in order to prevent it from being vented into the atmosphere where it contributes to global warming. Some CCS pilot projects have been launched but they are not cheap and they are far from proven.

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Given the magnitude of the problem of fueling the future with carbon-neutral energy, Nocera argues that the only real alternative for carbon-neutral energy production is some form of solar power. More energy from sunlight strikes the Earth in one hour than humanity uses in a year. But converting sunlight into energy useful to people is a huge unsolved technological problem. In 2000, author Richard Rhodes and nuclear engineer Denis Beller calculated that using current solar power technologies to construct a global solar-energy systemwould consume at least 20 percent of the world's known iron resources, take a century to build and cover a half-million square miles. Clearly a lot of technological innovation needs to take place before solar becomes an option for fueling the world.

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Comments

|10.30.09 @ 4:32PM|#

Okay, 22 terrawatts. Assuming you get an average of around 0.2 KW per square meter, you will need 110 billion square meters, or 110,000 square kilometers. About the size of Bolivia, roofed over.

Cost? Solar is currently running about $5 billion per GW. So figure $110 trillion.

Now, a small modular nuclear plant producing 25 MW is $25 million each. Figure we need about ten thousand...$25 trillion.

Which do you think the world is going to pick?