Why biodiesel?

The reason I chose biodiesel as an alternative fuel is that it can be used immediately: one doesn't need to be a serious hobbyist or car expert. It is much better than regular fossil fuels in terms of carbon use and emissions, and provides enormous flexibility of sourcing. It is not "the solution" to the energy question. In fact, what makes it appealing at the moment, is that it isn't burdened with being the only, or ultimate, solution. If everyone, overnight, chose biodiesel as their fuel, it would be a disaster. But as a smaller scale, temporary solution it is ideal.

Now is the time for biodiesel. It is a realistic, less polluting option, while humanity comes up with cleaner solutions. It really doesn't make sense to drive around wasting valuable petroleum, and contributing to you-know-what until a "magic bullet" is found. "The solution" is a path of intermediate, imperfect but improving adoptions. Moderation and innovation are what's needed, not bickering over perfection.

Here are biodiesel's advantages over many of the other alternative energy sources for automobiles.

Regular diesel cars can use biodiesel right now. They are commonly available as new and used models, unlike battery driven, hydrogen, compressed air or compressed gas cars. Gas/electric hybrids are now very available, but used ones are scarce and have the hybrid battery expiration problem (replacing a hybrid battery is expensive). New cars are often cleaner overall, but making a whole new car is very polluting. Diesel encourages buying or using older cars. Also, large commerical trucks, which use an enormous amount of fuel per mile because they require more strength to pull their weights, are very compatible with biodiesel. The "reduce, reuse, recycle" paradigm fits biodiesel more than any other alternative at this moment.

Biodiesel is very flexible. Ethanol, which is also very flexible in terms of sources, is a great option in that it works with many regular gas cars, but then one relies on regular gas engines, which are less efficient than diesel. Ethanol, too, can be produced from a variety of sources, but not from as many as biodiesel.  A diesel car can use biodiesel AND always has the option of being converted to a SVO/WVO, which in turn does not exclude using biodiesel or regular diesel as a backup. Biodiesel protects a car's backwards and forwards compatibility.

Biodiesel is non-toxic (well, just a little) and not explosive (at normal temperatures). If regional or occasional scarcity is a problem, carrying around containers of biodiesel in the car itself is a relatively safe option. Having larger amounts of it on your property does not involve significant hazards. There are no fumes, nor risks of sudden explosions. This "harmlessness" is actually very important, because it means that ordinary people can experiment with committing their car to biodiesel without fear.

Most importantly, biodiesel is a more democratic source of energy, because it can be produced from so many types of feedstocks or waste oils, and be produced by so many non-corporate elements of the population. It can be "home brewed" and even "home grown"(meaning the oils themselves are produced from seeds, grasses, algea, etc.)  In this regard, it resembles solar and wind energy, which can be produced privately, and distributed back into the market. With biodiesel/SVO/WVO/homegrown fuel there is the potential of a large number of people producing themselves and competing with larger conglomerates, undermining their monopoly. Ethanol and hydrogen are not democratic, they rely completely on a corporate elite of expertise and capital, not to mention on troubling government subsidies. Electric and plug-in hybrid cars also have the democratic sourcing potential, when individuals use solar, wind, or thermal energy to charge their cars,  but the car models aren't very common yet (although I expect this path to be the ultimate winner). The ideal car for the next 5-10 years, which no one seems to be producing yet, would be a biodiesel compatible, plug-in hybrid. Biodiesel and electricity would in such a case exponentially multiply each other's flexibility.