According to Bloomberg, theft of used fast food oil has become more common as its economic value has increased recently. There are a few interesting reasons for this:

Finding value in old grease isn’t new. For more than a century, the waste product has been processed into ingredients for everything from makeup and paint to pet food and livestock feed, according to the Arlington, Virginia-based National Renderers Association, which represents 51 companies with 205 plants in the U.S. and Canada.

What’s different is more cooking oil is being made into fuel. It’s now the largest use for old grease, at around 30 percent of demand. A 2007 energy law calls for American cars, trucks and buses to use escalating amounts of biofuels. Most of that is corn-based ethanol used in gasoline, but refiners also are making more biodiesel. Soybean oil is the primary raw material, followed by used grease and corn oil…

The rally in biodiesel is boosting the value of grease. Since Feb. 17, the fuel is up 12 percent to $3 a gallon, as of April 28. Further gains may be likely because of a trade dispute with competitors in Argentina and Indonesia, which may limit imports of biodiesel

So the value of, and therefore the incentive to steal, grease is on the rise due to a complicated set of factors involving fuel demand, government regulation, and international trade policy. If some of the biodiesel we are using in the U.S. is coming from palm oil plantations in the tropics, that adds another element to consider in the environmental benefits or costs of the technology. I also suspected that the typical burger joint owner who is paying someone to pick this stuff up doesn’t care all that much if someone else picks it up. From that person’s perspective, either way it goes away. I suppose the environment could be hurt depending on where it goes, and the licensed grease hauling industry gets hurt (and yes there is an industry association for that, called the National Renderers Association, and they are very concerned about this issue.

Do you want to make your own biodiesel? Here’s an article. Basically, biodiesel is vegetable oil either mixed with regular diesel or processed to change its properties so it can fuel a diesel engine or generator. If you try this please don’t poison, burn or blow yourself up. If you poison, burn or blow yourself up don’t say I didn’t warn you.

This is interesting on a small scale but I don’t think it’s the answer to civilization’s energy problems for a few reasons. The obvious one is that it takes a lot of vegetable oil, vegetable oil crops/trees take a lot of land to grow, and if you do it on a huge scale you will not have that land available for anything else, like growing food. We should be diversifying our economy away from our reliance on oil specifically, and liquid fuels more generally. Still, there are applications like air travel where liquid fuels seem to be the best technical solution, and it might make sense to reserve biofuels for those. If you need an emergency generator for some reason, like at a hospital, and battery or fuel cell technology are not up to the job or cost-effective enough yet, a tank of biodiesel certainly seems like a safer and less toxic alternative to a tank of regular old diesel.