You could say the bad news is that Bye Energy's plan for an electric Cessna 172 will have only two seats and an endurance of two hours. But the good news for flight schools might far outweigh those drawbacks. For one, the energy costs to fly the airplane are expected to be less than $10 per hour. Time between overhauls on the electric motor are expected to be as much as 25,000 hours, decimating maintenance bills. Power comes from a bank of lithium ion batteries, solar panels and innovative windmill technology that reclaims energy from the wingtip vortices. The electric motor (rated at the equivalent of 180 hp) weighs just 42 pounds, and there is obviously no fuel load to consider, but those weight savings are offset by the battery pack. The nose will be more tapered, and a six-blade composite prop will provide more efficient thrust (since its role as an engine-cooling fan is off the agenda). Weight and balance are said to be unchanged from that of a conventional Skyhawk. The combination of electric motor and new prop also promise much quieter operation in the training environment. Bye Energy President George Bye hopes to have a proof of concept aircraft flying (with a more conventional two-blade propeller) sometime next year.