This week the City of Gumi in South Korea is trialing a brand new type of electric bus that gathers a charge from the road beneath its wheels. Gumi has two of these new Online Electric Vehicle (OLEV) buses, which were developed by the KAIST Graduate School for Green Transportation and named one of the top 50 inventions of 2010 by Time Magazine.
The OLEV buses are environmentally friendly vehicles that draw electrical power from the road they're driving on via electrical cables that are buried under 5- to 15 percent of the surface of the road. The road is able to distinguish between regular vehicles and OLEV buses and will 'switch on' the power strips when OLEV buses pass along. The cables embedded in the asphalt create magnetic fields, and a receiver on the underside of the bus converts it all into the electricity to power the bus. The trial route for the buses stretches for 24 km and runs from Gumi station to the In-Dong district. According to KAIST (via Vice), the buses will receive 20 kHz and 100 kW (136 horsepower) electricity at an 85 percent maximum power transmission efficiency rate while maintaining a 17 cm air gap between the underbody of the vehicle and the road surface.
"It's quite remarkable that we succeeded with the OLEV project so that buses are offering public transportation services to passengers," said Dong-Ho Cho, a professor of the electrical engineering and the director of the Center for Wireless Power Transfer Technology Business Development at KAIST. "This is certainly a turning point for OLEV to become more commercialized and widely accepted for mass transportation in our daily living."
Gumi City plans to build a whole fleet of OLEV buses beginning at the end of the year, with plans to put 10 more on the road by 2015.
Yes...and no...mostly no.
The thoretical maximum efficiency for a piston engine is about 40%. In the real world more like 25% would be considered good. And that would be peak real world effiency which only happens in a narrow power band. With lots of stop/start cycles you are usually at a much worse value.
Turbines on the other hand routinely operate in the 60% efficiency range in the real world. And they spend most of their time in their most efficient power range.
So they could drop down to ~45% transmission efficiency and still beat a good piston engine. At 85% they should be using about half the power.
Then there is the benefit of centralized power. Its far easier to control emissions on one power plant then 100,000 vehicles. And its far easier to replace 1 power plant with cleaner technology then to get 100,000 peopel to replace their old vehicles. As soon as a newer technology comes along that is cleaner you just replace the one centralized source, and everything down the line gets the benefit.
So yes its true its no zero emission, but worst case its far better.
I bet these buses are a lot quieter than diesel too, so it will improve not only particulate pollution but possibly noise pollution as well.