It Ain’t Easy Being Green

Electric planes. They were the domain of RC models. Recently, there's been a number of full size prototype planes taking to the air. With increasing environmentalism and the skyrocketing costs of Avgas it was bound to happen. They're quiet and have less vibration. The downside: Sketchy power, slow speed, limited payload and range. All the things that matter to pilots.

I did a brief rundown since some of these will be prominently featured at Airventure in Oshkosh, WI. I'll be there next week. Coincidentally, I was drafting this missive as the lastest issue of Smithsonian's Air and Space Magazine arrived, also featuring electric planes. They trace the history and recent developments quite well.

During my search for more information, I tried to understand why money and effort were chasing this technology. A good deal of interest, from eccentric inventors all the way to to well funded research teams. The more prevalent are the plug (in) and play types such as the Chinese Yuneec: A twin seat, single engine light sport plane that charges in three hours and runs for two and half hours at a price of $89,000.



The Electraflyer is a motoglider with a battery pack. Cruise speed at about 70 mph with a top speed of about 90. The plane will fly between 1.5 and 2 hours before it needs a recharge. The Italians recently launched the SkySpark with the initial flight video here. Ultralights also get into the act. The more recent entry includes the E-Spyder with a breathtaking speed of 55mph and time aloft at 40 minutes. This is fine if you want to take see what the airport looks like at 500 feet but where else could you go?

Then there's the self powered ones. More exotic than a plane that runs on batteries. The Solar Impulse has a gigantic wingspan of 200 feet and 650 square feet of photovoltaic cells. Even with the plane’s four motors it can only achieve an average speed of around 43 mph. The wingspan is as wide as an Airbus 380 which is the only way it can stay stay in the air at that speed. The "glider like" Sunseeker also uses solar cells. I was especailly intrigued by the German built Antares DLR-H2 . The power to the motor is provided by a fuel cell, hanging under the left wing, fed by hydrogen fuel from a tank under the right wing. The fuel cell converts hydrogen directly into electricity using an electrochemical reaction with oxygen in the atmosphere.

So why bother? Presently, these planes seem underpowered and from a safety standpoint, how do you make a "go -around" at the last minute? An emergency application of power to help preclude an accidental stall? How much utility do they offer?

Not much.

For now it's like a hybrid car. Like many Prius drivers on the road today, you really can't justify the cost. You fly it for it's own sake. Someday the technology will improve and fuel will only get more expensive. Only a quantum leap in power and energy storage will make it commercially viable. I expect it will happen around the same time everyone is driving a fully electric car.