Ineos Bio, a Florida company, announced last month that it had produced ethanol from gasified wood waste, using a method that it expects to be commercially viable, and KiOR Inc. will make one million to two million gallons of diesel and gasoline this year from wood waste at its plant in Columbus, Miss., according to Michael McAdams, president of the Advanced Biofuels Association. Mr. Hart said Sierra Energy’s technology should be complementary with the Florida company’s; the FastOx turns all municipal waste, not just wood scraps, into a gas that Ineos Bio could then transform into ethanol.

The FastOx gasifier is the brainchild of two former engineers at Kaiser Steel, patented by the grandson of one of them and commercialized by Mr. Hart. “It’s a modular system that can be dropped into any area,” Mr. Hart said, “using waste where it’s produced to make electricity where it’s used.” Once it’s off the ground, he said, “garbage will be a commodity.”

From concept to construction, the story of the FastOx is of one fortuitous accident after another. And while Sierra Energy has not yet proved to be a successful company — it will be a long while before your garbage is shoveled into a FastOx — its system has become the first waste-to-energy technology acquired by the Defense Department, which paid $3 million for it through an environmental technology program. (The California Energy Commission, which supports renewable energy development in the state, also gave Sierra $5 million, to cover the portion of Sierra’s costs that the Pentagon couldn’t.)

The military is looking for ways to reduce its oil consumption, and to make it easier to supply the front lines with the fuel it uses in all its vehicles and generators. “These days, the supply lines are in the battlefield,” said Sharon E. Burke, the assistant secretary of defense for operational efficiency plans and programs. “And we consume a lot of fuel, which makes us a big target.”

MIKE HART got into the energy business by way of a train. In 1993, he bought the Sierra Railroad, a small freight and tourism line in Northern California. During the California blackouts of 2001, he had an idea: “As the lights were going out, I realized every one of my locomotives creates 2.1 megawatts of electricity,” he said — enough to power many hundred homes. “It’s a rolling generator, and inexpensive.”