This fall, 13 planes will vie for $1.65 million in prize money. This is the CAFE Green Flight Challenge 2011, a competition for “quiet, pratical, green aircraft,” and the CAFE Foundation, which is organizing the competition, claims that the bounty on offer is the largest ever for a civil aviation competition. To win first prize, the planes will have to show that they can fly at a ground speed of at least 100 miles per hour, and that they can fly 200 miles using only the energy equivalent of one gallon of gasoline per passenger. Most competitors are electric. The others rely on biodiesel fuel or hybrid engines.

They don’t look anything like the behemoth airplanes most of us fly in. The largest wingspan any of the planes boasts is 75 feet, about a third of the wingspan of a Boeing 747. The smallest wingspan is 15 feet, smaller than some of the first gliders the Wright brothers flew, and most of the planes have only one or two seats. 

The CAFE Foundation, which is organizing the competition, has done research into small aircraft for decades. (CAFE stands for Comparative Aircraft Flight Efficiency.) It’s small, relatively obscure group, but the money for the competition is coming from a couple of organizations you may have heard of: Google is sponsoring the test flight, and NASA put up the prize money. The test flight will take place in California, where the electric planes will charge up at a geothermal plant just north of Santa Rosa.

One goal of the competition is to show that "practical, emission-free cross-country flight is possible." On the following slides, check out some of the competitors.

Photo courtesy of NASA.gov

Eric Raymond's e-Genius: a 60kW electric two-seater. 

Jim Lee's PhoEnix: a 44kW electric two-seater. 

Ira Munn's SERAPH: a 30kW biodiesel-hybrid single-seater. 

Greg Stevenson's Econo-Cruiser 3000: a 15kW bio-fuel-hybrid two-seater. 

John W. McGinnis's Synergy: a 142kW bio-diesel six-seater. 

Richard Anderson's EcoEagle: a hybrid-powered two-seater.

Lawrence Speer's Greenelis PXLD: a 30kW Diesel-fueled two-seater. 

Gene Sheehan's 16 kW electric-motored single-seater.

Einar Enovoldson's Elektra 1: a 21kW electric single-seater.