El Al Israel Airlines will convert many of its Boeing 737s to hybrid power, using electricity to move planes on the tarmac. The move will save fuel, cut emissions and reduce the time spent waiting for a tug to tow airplanes to and from the gate.

The airline plans to outfit the aircraft with WheelTug electric motors that drive the nose gear using energy from the plane's auxiliary power unit. Beyond eliminating the need to fire up the jets to taxi, WheelTug says the device can eliminate the potential bottleneck that comes with waiting for a tug.

By using the APU instead of the main engines to taxi, a 737 operator can cut fuel use during ground operations by 85 percent, according to the company. The amount of fuel used on the ground is but a fraction of what's burned during flight, but the benefits can add up for airlines looking to save every possible dollar.

WheelTug chief pilot Joseph Goldman says a typical Boeing 737NG burns around two gallons a minute while taxiing with just one engine. That fuel can be saved by drawing power from the APU, which is running anyhow. In addition to burning less fuel, the electric propulsion means the plane can carry less fuel, saving weight – and further reducing fuel consumption.

"Even if taxi-out is officially expected to take 15 minutes," Goldman said in a statement, "I may plan for 45 minutes to cover an unplanned shutdown."

WheelTug estimates several hundred dollars can be saved on every flight.

The twin electric motors and accessories installed on the nose gear weigh about 300 pounds. WheelTug says the system is weight neutral because it is offset by the ability to carry less fuel. Using the motors, the pilot can taxi at speeds up to 28 miles per hour.

Several companies are exploring similar ideas to eliminate the need to run the large main engines on the ground. WheelTug is the first to announce a launch customer with a device that can be retrofitted to existing aircraft without installing external power supplies or resources.

Beyond the fuel savings, airlines can reduce delays by eliminating the need to rely on tugs. Delays mean lost revenue, so it provides airlines with another way to cut costs and increase the bottom line. The electric drive also reduces the chance of an engine being damaged by ingesting debris, something that most often happens on the ground.

WheelTug hopes to have the system certified by 2013. It also is developing a version for the Airbus A320 series. El Al Airlines hopes to equip 20 of its 737s with the system upon certification.

Photos: Drewski2112/Flickr, WheelTug