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400 miles per gallon, in a plane
Green flight expo at Moffett shows the possibilities

by Daniel DeBolt

Just before soaring like a graceful bird over a mesmerized crowd at Moffett Field on Monday, a Slovenian-built electric plane was declared the most efficient airplane in the world and won the biggest money-prize in aviation history: $1.3 million, donated by Google.

The Pipistrel Taurus G4 made its record-breaking 200 mile flight over Sonoma County last week. The twin-fuselage design carried an unprecedented payload for an electric plane, four passengers and 1,000 pounds of lithium-polymer batteries. And it was pulled by the most powerful electric motor ever put in an airplane, with 194 horsepower, according to Pipistrel officials.

At an average speed of 100 miles per hour, the result was the electric equivalent of 101 miles per gallon of gasoline, or 403.5 "passenger miles per gallon," as the competition multiplied each plane's mileage by the number of seats.

Google sponsored the contest, which provided $1.65 million in prize money to the contestants, including $80,000 for the second place E-Genius plane, an electric two-seater from Stuttgart University in Germany which achieved 375.8 passenger miles per gallon.

The event was organized by NASA and the Comparative Aircraft Flight Efficiency Foundation. The foundation has been running such contests since the gas crisis of the 1970s, when 20 miles per gallon was a major feat for a plane. Technology has changed rapidly.

"Two years ago, the thought of flying 200 miles at 100 miles per hour in an electric aircraft was pure science fiction," said Jack Langelaan, leader of Team Pipistrel-USA.com.

The Slovenian-built Pipistrel was flown by David Morss of Redwood City and Robin Reid of Independence, Ore. Concrete blocks took the place of two additional passengers. The Pipistrel was the only plane in the competition that could hold more than two passengers.

The E-Genius and the Taurus G4 were the main contenders in the event as the only purely electric planes.

In comparison to the electric planes, a gasoline-powered entry from Florida, the Phoenix, was able to achieve 94.3 passenger miles per gallon with two passengers. Like the other planes in the event, the Phoenix is based on a glider. It weighs half what the electric planes do at just 754 pounds when empty.

Aviation journalist Dean Sigler was enthusiastic about what may be a bigger accomplishment than most people realize, even in the aviation world.

"If your car were going 100 miles per hour you wouldn't get anywhere near that efficiency," Sigler said.

Email Daniel DeBolt at ddebolt@mv-voice.com

Posted by GC, a resident of the Sylvan Park neighborhood, on Oct 11, 2011 at 7:41 pm

I was impressed reading 400 miles per gallon. Then I read electric motors and batteries and knew this is more funny math. Then there the part that says an 100 electric miles per hour = 101 gas miles or 403.5 passenger miles. No wonder the country is broke and can't balance a budget. We have inflated numbers so that no one can use the information. Wait, my cell phone just went 150 mph and got 1000 miles to a gallon.

Posted by Bill, a resident of the The Crossings neighborhood, on Oct 11, 2011 at 8:02 pm

The claim is 403.5 passenger miles per gallon.

Or it carried 2 passengers 201.8 miles in the equivalent of one gallon of gas energy converted to battery power.

You can thus say a SUV that gets 10 MPG with 6 passenger inside actually gets 60 passenger miles per gallon.