Is there a type of electric generator that uses just enough fuel to run the appliances plugged in?

Question

...you plug in a radio, a little model airplane motor powers it, a toaster, a bigger motor comes on, a vacuum cleaner, a bigger one powers up, etcetera....if it was diesel, you could convert it to run on vegetable oil....

Answer 1

New fuel cell uses germs to generate electricity

Scientists at the University of Massachusetts at Amherst announced yesterday that they have built a novel device that uses bacteria to turn garbage into electricity.

"There is a scene in `Back to the Future' where they throw a banana in the car and off it goes," said Lovley. "We are not at that stage yet, but this is a big step from what these fuel cells were able to do before."

Answer 2

There are generators that idle along unless they see an increase in draw and then go back when the load is removed or reduced.  They're really cool and help to keep your work area quieter.

Answer 3

Honda and many others have what is called the ECO throttle that is load sensitive, the larger the load the higher the engine revs the lower the load the slower the engine runs which consumes much less fuel.

My Honda EU2000i can go and does run15 hours on less than a gallon of gas because of this feature.

As far as diesel generators running on Bio-diesel it does work and diesel generators have come way down in price this past year too!