In Sweden, they burn bunny rabbits for heat. More specifically, rabbits from Stockholm that have been culled to battle overpopulation are freeze dried, shredded, and burned in a power station to provide energy to heat homes. Obviously, some people have a problem with this. On one side of the argument, animal rights groups (such as the Society for the Protection of Wild Rabbits) say that culling rabbits and using their bodies for fuel is like ignoring the main problem of overpopulation and turning the killing of rabbits into an industry. On the other side, the purveyors of bunny death say that other methods of dealing with overpopulation simply displace the problem without diminishing numbers. Overpopulation is bad for everyone, including the bunnies, so reducing their numbers through culling is the best option. The ability to use their furry corpses as fuel is just a convenient afterthought.
All patronizing aside, the use of animal byproducts as fuels is not isolated to Scandinavian bunny hunters. The use of animal fats as fuel is very old. Lighting devices that rely on animal fat have been around for thousands of years. More recently, people have started seriously looking at a broader range of animal byproducts as fuel sources. The facility in Sweden that actually burns the rabbit carcasses is not limited to rabbits. In fact, the power station only gets a very small part of its fuel from the desiccated ex-rodents. They also use pigs, cows, moose, reindeer, wood chips, peat, and a variety of other wastes that are all ground up and chucked into the furnaces. Really, any animal that has expired for any reason can be burned for fuel. This even includes expired meat from the grocery store.
Obviously, animal carcasses are not the most useful of fuels. They don’t pump well, wouldn’t work in an internal combustion engine, are expensive to raise, and they smell pretty foul. Is there some other way that this idea could be used to obtain energy? The answer to that unnecessarily leading question is yes. In Alaska, a number of communities are already using the waste fat from fishing industry to generate heat. This technology is already economically viable and much better for the environment. The fish fat is non-toxic and doesn’t produce the harmful byproducts that you get when you burn petroleum.
Animal fat can be turned into biodiesel as well. Biodiesel from animal fat is very similar to biodiesel from plant oils. The only major difference (other than source) is that animal based biodiesel solidifies at a slightly higher temperature than plant based biodiesel. When blended with normal diesel, the two fuels are essentially identical. This fact has not gone unnoticed by the agricultural industry. Those same fisheries in Alaska may soon have the capacity to produce biodiesel from their fishy fats. Other places near fishy facilities could find fish fat fortuitous for foregoing conventional fuels. Technology to utilize fish waste is being developed for use across Europe. Switching from seafood to poultry, there are currently plans to build a $5million plant to convert the 2.3 billion pounds of waste fat from a Tyson chicken factory into an estimated 3 million gallons of biodiesel each year.
While the total energy from animals that we could utilize is small compared to the total global energy needs, the use of animal products as fuels is not to be overlooked when considering alternative energy sources. Policy decisions are already shaping the growth of this corner of the energy industry. For example, some places, such as the US and EU, have banned the dumping of raw meat in landfills. Various forms of credits for green energy can also spur a growth in this market (Tyson and Purdue are testing chicken fat-biodiesel trucks for addition to their fleets).
So as for the bunnies, cute and fluffy is nice, but warmth and electricity is better.