While hybrid buses take a good thing (i.e. mass transit) and make it better by improving efficiency and limiting pollution, plug-in hybrids represent the next step in improving that technology. By allowing buses to get more of their juice from the grid, and less from diesel, emissions are drastically reduced. This fact holds true even when dirty coal is used as the power plant’s energy source – but the beauty of using electricity is that other, greener sources could also be incorporated.

The limit to any plug-in electric or hybrid that is supplemented by grid-power is the plug. Even in the case of the hybrid that can rely on diesel firepower when the batteries run low, maximum efficiency occurs in electric mode. Rather than needing to constantly run back for a recharge,  Hino, the heavy-duty vehicle subsidiary of Toyota, has developed a rather ingenious solution: wireless recharging.

Hino’s new fleet of buses is currently undergoing a two-week testing period at Tokyo’s Haneda airport where the buses cover a 4.2 kilometer route.From Japantruly.com:

Charging a large amount of electricity quickly without using cords enables the bus to provide longer distance services. For the next two weeks, it will link Haneda’s first, second and international terminals three times in the morning and again in the afternoon, covering a distance of about 4.2 kilometers. Since the bus uses only electricity, carbon dioxide emissions are reduced by about 60 percent compared with regular buses.

Thanks to AutoblogGreen for doing the grunt work and deciphering some of the Japanese explanation of how the charging system works.From AutoblogGreen:

Now, about that cordless charging. Apparently it is using an electromagnetic inductive charging setup. There is a coil on the bottom of the bus and also one embedded in concrete. The efficiency and speed of the charging system is not stated and I couldn’t tell whether or not it employs magnetically coupled resonance.

That’s some cool tech that allows mass transit to run on established roads (with chargers added in) but performs similarly to an electric rail. Seems to me that a fully-electric, rather than a hybrid model, shouldn’t be such a big leap.