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.)

Hydrogen from gasoline: ExxonMobil TV commercial

After seeing the new ExxonMobil TV commercial about the company's technology that produces hydrogen from gasoline on board a vehicle, I got curious. How exactly does one derive hydrogen from gasoline in a moving car?

First, some context. Hydrogen is the essential fuel for fuel cells. But our hydrogen infrastructure is in its infancy. The difficulties of supplying and storing hydrogen in cars have hindered widespread adoption of fuel cells in automobiles.

At the same time, we have a mature distribution system for gasoline, and storing the stuff in cars is no sweat. What better solution to fuel-cell power woes than converting gas to hydrogen while it's inside a car?

I dug around a bit, and learned that the technology for extracting hydrogen from gasoline and other hydrocarbons has been around for a few years. The gasoline is made to react with steam at high temperatures in the presence of a catalyst, and that liberates hydrogen from the gas and the water. There's a little more to it -- the hydrogen then has to be separated from other gases before being fed to the fuel cell -- but that's the basic scenario.

To commercialize the technology, ExxonMobil has partnered with 3 other companies and Ben Gurion University of the Negev (Israel). They plan to test their new hydrogen production system in forklifts, and eventually roll it out to passenger vehicles.

If the plan works, fuel-cell-powered cars will be as common as, well, gasoline-powered cars today.

Alternative-energy purists may carp that this technology still requires use of fossil fuels. They may want to look at the bright side.

If converting gasoline to hydrogen improves fuel economy by 80%, as the TV commercial claims, then that means we need to use only one-fifth as much gas as we do now. Not a bad trade-off for putting more fuel-cell cars on the roads more rapidly.

One question remains, though. After the hydrogen is stripped from the hydrocarbon, what happens to the carbon?

Inanimate objects moving without motors or internal combustion engines

Imagine a strip of flexible plastic film that walks and flails about without anyone pushing it. That's exactly what chemists at the Tokyo Institute of Technology, Japan, have created.

Good-bye, motors and internal combustion engines?

Maybe not. Or maybe, just maybe, someday. After all, living things move without either of the above.

But even if we manage to do away with motors and engines, we'll still need some form of energy for propulsion. (Remember, you can't create energy. You can only change it from one form to another.)

The plastic strips the chemists developed needed energy in the form of light before they could move.

In fact, the chemists had to use two kinds of light: visible and ultraviolet. They had made the film from a polymer that changes its orientation depending on the kind of light that shines on it.

When visible light falls on this polymer, the polymer bends. Under UV light, it flattens. By pointing visible and UV lights at strategic places on the film at well-timed intervals, the chemists made the film curl and straighten, and seemingly sally forth on its own accord.

Imagine the possible applications if this technology reaches the market. The leader of the group that made the film mentions "light-to-mechanical energy conversion," which sounds quite innocuous until you realize he is talking about a way to make objects mobile.

Here are a couple of videos that show how the film traveled: