When is a Plant not a Plant?

You’re probably aware that the US government is spending huge amounts of money to support production of biofuel. What they tell you is that this fuel will reduce our dependence on foreign oil and that it is better for the environment. It turns out, at least the way that biofuel is produced now, that neither claim is true. It takes more energy to produce the biofuel than it produces, and our topsoil is taking a beating. Add on top of that the finite amount of water that we’re pulling from wells across the midwest and ask yourself the question: would you rather run out of oil or run out of farmland?

Granted there are many plants that are much better candidates for creating biofuel than corn, the main crop used now, and even corn production could be made more efficient and less destructive to the soil. Still, perhaps it’s time to step back and look at the actual problem we are trying to solve. A better solution just might present itself.

What we are trying to do is make solar energy portable. Plants do that using photosynthesis — they put some carbon dioxide and some water next to each other and wait for a photon to whack the system just right, and out comes an energetic molecule, and some nice free oxygen to boot. It’s a pretty slick system. What we are doing now is using plants as solar collectors. We set them out in the sun, give them access to (lots of) water and carbon dioxide, and later we chop them down and collect the energy. Of course, the form of the energy isn’t quite right (sugars aren’t good fuel), so we have to process the result, using up some of the energy we collected.

The goal, then, is to turn sunshine into gasoline, alcohol, or some other handy hydrocarbon.

Flash back to when you were in grade school science class, watching a movie about how plants work. We zoom down into the animated land beneath the surface of the leaf where the magic is happening. A little wizard is hard at work, gathering the ingredients, then… at the critical moment he gawps at the camera, eyes round, and pulls a screen in front of his workbench. “We don’t know what happens back there,” the narrator says in his happy-narrator voice, “but what comes out is…” (I don’t remember exactly what comes out. ATP? You can look it up.)

Bumblebees. Photosynthesis. Great mysteries when we were kids, but not anymore. (Did no one mention to you that bumblebees can fly now? They have tiny horizontal tornadoes raging just above their wings. Sometimes the explanation is even cooler than the mystery.) Anyway, photosynthesis. Somehow, films made before DNA had been discovered still have us convinced that some things are unknown. I’m no photosyntholigist, but I only have to glance at wikipedia to know that the process is pretty well-understood today.

So I ask you: Do we really need the plant? We know how that stuff works, and we can reproduce it. Can we not create a solid-state device that captures solar energy and puts out an energetic molecule – the exact molecule we want as an end product? We could use such a device to create fuels with absolutely no impurities (no sulfur, for instance), and no net carbon footprint. The system does not have to be very efficient to easily outdistance existing plant-based methods, and it would use land that has much less value in terms of ongoing human prosperity. Farms could go back to growing food.

Picture a gas station on the highway between Los Angeles and Las Vegas. Behind it there is an array of dark panes stretched over the desert floor. From the array a pipe leads to a holding tank which holds the highest-quality gasoline money can buy. And the cost to the dealer is fixed – he just has to pay to maintain the system.

There would be environmental impact, of course. Vast tracts of desert would be shaded, and somewhat cooler as a result of energy being removed from the system. Although our machine would use a lot less water than a living plant, (or perhaps another source of hydrogen?), there would still be some demand. Overall, though, I think environmentalists would see it as a lesser evil.

I’ve been kicking this idea around for years, now, but apparently I haven’t ever written about it here. The plan is filed under get-poor-quick, but man, if anybody got something like this working, they could become some kind of ridiculously wealthy. As well they should.

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