My family's journey to the land of biofuels began when my wife, Elizabeth, and two of her friends, Rosa and Ellen, bought subcompact diesel automobiles. They researched hybrids, but because we live in a rural area, with no stoplights, sparse traffic, and vast distances, diesel appeared to be a better choice. Given their desire to consume less energy, the 45-mile-a-gallon (72 kilometers) vehicles seemed perfect. They were further swayed by the recent introduction of ultra-low sulfur diesel that significantly cuts emissions, as well as the cars' ability to run on biodiesel. As its name implies, biodiesel is fuel processed from biological sources instead of petroleum. It is renewable, nontoxic, and typically reduces greenhouse gas emissions by more than 60 percent over conventional diesel.

Now alternative fuels are a topic of conversation in my family. My children are intrigued with the thought of riding in a car powered by used cooking oil from the local fast-food restaurant. We've pointed out that biodiesel comes from sources like soybeans, but the concept of a soybean-powered car bored them. We recaptured their interest, however, when we mentioned the promise of algae as a biofuel. My ten-year-old son, Tim, thought the cool quotient of algae surpassed that of cooking oil. But my teenage daughters, Noel and Louise, preferred the idea of filling the tank with cooking oil in the hope that the exhaust would smell like french fries.

Is biodiesel the answer to the energy and environmental challenges we face? Not by itself. But it is a step in the right direction when combined with other innovative solutions. Besides, filling up your car with biodiesel may provoke some interesting family conversations.