While living aboard a cruising sailboat we try to be as friendly as possible to the environment.
But I have not found a way to completlely do away with the use of fossal fuels.
Our dinghy's outboard uses gas as does the generator we use to charge our batteries when solar power is not enough.
One day, when I hit the lottery, I will install a wind-generator.
That will cut down even more on the need for gasoline onboard.
Of course there will always be the need for diesel to power our engine when the wind doesn't blow.