To Hybrid or not to Hybrid (buses that is)

Image by paulkimo90 via Flickr
Hybrid buses...some transit companies have gone crazy having all new buses be hybrids while others such as TriMet in Portland and the Utah Transit Authority have been more conservative when it comes to buying hybrid buses. Back in 2002 TriMet received two New Flyer Hybrids while UTA received three of the same type of buses.

After evaluating TriMet made the decision not to order any new hybrids until this year because they did not see enough savings to justify the initial high costs of the buses. However, last year UTA received 10 Gillig Advantage BRT hybrid's to go along with a purchase of new regular diesels, and this year TriMet has decided to see how much the changes in hybrid technology in the last decade has changed and ordered 4 hybrids also from Gillig to evaluate their performance.

Some would argue that Hybrids use less fuel so transit agencies should by them. Of course life is a little more complicated than that. In fact the experience with hybrids have been a mixed bag largely because how well they save on diesel depends of the type of service they are used on.

New York is probably one of the biggest users of hybrid buses. In an environment like crowed New York streets were many of the buses are sitting in traffic or traveling at low speeds the hybrid technology pays off. However, in Seattle the opposite situation exists. Seattle purchased their hybrids to travel in their bus tunnel when it became a joint operation with Sound Transit Light Rail. However, once the buses leave the tunnel a number of them become express routes across the Seattle area. Because they spend a majority of their time travel at higher speeds Metro does not see the advantages of Hybrid technology.

Here is a article from Seattle about the performance of their hybrids from a few years ago:

Hybrid Buses Fuel economy promises didn't materialize 

Some later numbers may show some better performance from diesels including maintenance cost however lets look at some important numbers:

Currently Hybrid buses cost substantially more than standard diesel buses. For example TriMet's new hybrids cost approximately $650,000 while the new diesels that TriMet ordered this year coast about $400,000. So lets look at some examples to show what would make this purchase justify itself.

As you can see above the difference in price between the regular bus and the hybrid bus is $250,000. Let's say a standard bus gets 4 miles per gallon and a hybrid averages 5 miles per gallon. That means that you would save one mile per gallon. For the sake of this example and to make the numbers easier lets say that the transit agency will put 500,000 miles on it during its life at the agency. Also let's say that the average price of diesel during the life of the bus is $3.00 per gallon to keep the numbers easier. With this example the agency would spend $375,000 on fuel for a diesel bus and $300,000 for the hybrid.

The $75,000 savings does not justify the initial cost of they hybrid. In this example it is virtually impossible for the Hybrid to justify its initial cost. There is other factors that need to be considered beyond just fuel cost such as maintenance and resell value but that would most likely go in favor of diesel for maintenance and resell value is so small it is irrelevant anyway.

When making decisions on what type of bus to buy we need to look at hard numbers and not just try to feel good. But there is also something to be said for going beyond the bean counter numbers. Hybrid buses can offer other benefits that cannot be looked at on a balance sheet such as quieter operations and points on the political and public relations front.

On a profit and loss statement the hybrids may not add up, other factors may be in their favor but a transit agency needs to look at the the life of the vehicle and whether the substantial cost will pay off in the long run.