A German doc not only proposes solutions to the world’s energy problems but also solved the biggest problem facing indie filmmakers: financing.

The Fourth Revolution — Energy” was made for 1.25 million ($1.7 million). Director Carl Fechner raised

the budget from some 150 donors — ranging from individuals to solar-power companies — who contributed mostly smallish amounts of at least $1,400.

People want answers and they want a vision,” says Fechner, who teamed up on the pic with the guru of photovoltaic energy in Germany, Hermann Scheer, after he had written a book called “Energieautonomie” (Energy Automony) in 2006. “It’s a film from the movement for the movement.”

After Fechner decided he wanted to make the film in 2006, he set up a website to raise funding for it — called crowdfunding.

From the outset we contractually banned any influence on the content of the film from any financial investor,” says the helmer.

A young solar power magnate, Matthias Willenbacher, signed up, contributing $750,000, the largest single amount. And after a three-hour chat with Fechner about the pic he ended up in a cameo as the dynamic renewable entrepreneur in the pic, which also features Nobel laureate Mohammad Yunus.

Revolution,” which shows how the industrial world could manage to keep spinning while running on purely renewable energy sources such as giant solar power plants and wind parks, bowed in Germany after a gala March 16 Berlin preem.

The film has gotten mostly favorable reviews and lots of headlines for coming up with possible answers to many of the questions raised in “An Inconvenient Truth.”