8 Non-carbon energy sources

Two ways to reduce carbon dioxide emissions from power plants:

1. Use existing technologies and better carbon-management practices to cut CO2 releases. Scientific American magazine calls this Plan A.
2. Generate energy through new technologies that bring emissions down to zero -- Plan B.

The Scientific American story linked above is a recent repost of September 2006 story that focuses on Plan B. It describes 8 potential energy sources that discharge no CO2.

Some of the technologies the story mentions have advanced somewhat, while other new ones have emerged. It's an interesting analysis of what's out there. I found myself generally agreeing with the author's predictions.

The 8 energy sources are:

1. Nuclear fusion. Considerable progress has been made in this field since the Scientific American story ran.
2. High-altitude wind. Some serious winds blow at 33,000 feet, where, at certain latitudes, they pack 5,000 to 10,000 watts of power per square meter.
3. Sci-fi solutions, such as cold fusion, bubble fusion, and matter-antimatter reactions. Unrealistic, says the story's author.
4. Space-based solar power. In space, the sun never sets.
5. Nanotech solar cells. Because it's going to be a long time before silicon-based solar cells can compete with grid power on price.
6. A global supergrid. A worldwide network of supercooled, superconducting wires. Not so much a source of energy as a means of efficiently distributing it.
7. Waves and tides. These sources are already being tapped in several places around the world. A proposed project in the UK's Severn River will be the world's largest.
8. Designer microbes. Bespoke cells that could, for example, convert cellulose to fuel, or turn the carbon dioxide from a smokestack into natural gas.

(Photo: Carbon dioxide crystals. Credit: USDA Beltsville Agricultural Research Center.)