Any transit fan who rides an electric bus will admit to admiration of the strong silent acceleration and the total absence of tailpipe emissions. To appreciate the role of the ETB in transit systems, however, we need to step back and get the bigger picture of what these systems are.
By definition, the systems are large. They maintain service that has been provided, in many cases for over a century, and the equipment they use is intended to last 25 years, implying the continuance of service. In many cases they include a large sunk investment that can’t be recovered if service ends, they usually have many large things on quite a bit of real estate, and when they drink fuel, they don’t use a soda straw.
Consider the railroads in the age of steam. To generate steam you needed coal and water, so each railroad had two parallel structures to provide the coal and water. Steam locos liked to eat and drink every hundred miles, and these frequent stops were more convenient in the days of hotboxes and wayside setouts of cars.
Thus, every steam railroad was a series of small towns, with coal and water storage, and often a railroad hotel or YMCA for train crews. At the end of the age of steam, the steam loco still had a greater thermal efficiency than the diesel, but the cost of maintaining the fuel and water supplies was prohibitive.
Maintaining the fuel supplies for the railroad, indeed, requires an investment so great it becomes a matter of long-term financial planning. Fuel stocks must be maintained to provide service in case of disruptions, and to hedge against market spikes. In the age of coal, this meant mountains of coal stockpiled in the summer months against the anticipated strike of the miners in the winter months. In the age of diesel fuel it means tanks in the ground and contracts for guaranteed deliveries. Large electrical users need to be sure the grid can overcome local disruptions or that they can generate their own essential energy.
In many respects electricity is the best energy source. You don’t need to keep tanks of it on hand, you don’t need to pump it into buses in the morning, you don’t need to carry the weight of the electricity around with you, and you don’t need to deal with the problems of leaks, fire danger, and emissions. An enormous world manufacturing base is constantly trying to improve the performance of electric motors and transit systems have already tried just about everything, so there’s a lot of experience to draw on.
The problem with electricity is that it requires a very large capital investment to deliver the electricity to the bus, usually by overhead wires. That’s a big problem for a transit system, but is it a problem or an opportunity for the society it serves? That’s probably a good topic for another post on electric buses.