Hybrid is no longer optional

After some delay due to the economic crisis that hit the industry in 2008, Volvo introduced the first commercially viable hybrid bus in 2010.

We were lucky with the timing. Not that the market recovered, but it gave us some margin to the start of next big challenge, the Euro VI emission. It meant that we had experience from more than 200 hybrid buses in commercial operation late in 2011, when we had to decide on which buses to take to Euro VI, that will become mandatory from 31st of December this year.

No doubt, the market organization within Volvo Buses is under pressure to present a menu of different technical solutions for each possible request from city authorities. In some cities ethanol fuelled buses are preferred, in other cities natural gas or biogas is the choice and in most cities (~95% of the market) diesel fuel is used. Then again, other cities focus on total cost and others put requests for decreased greenhouse gas emissions or energy use. 

In some cases the EU mandatory directive ( 2009/33/EC ) to consider hazardous emissions of hydrocarbons, nitrogen oxides and particulates in combination with emissions of greenhouse gases and energy efficiency is applied. The spirit of the directive is to drive the development of clean and energy efficient vehicles and to harmonize the demand from cities in Europe.

However, with the experience of our low floor and double decker hybrid technology we had the information required to benchmark our diesel, gas and hybrid buses against one another. The feed-back from operators was a big help. The fact that we were forced* to make most of the development in-house gave us cost control and competence. When all aspects (ranging from total cost for the operators to environmental performance in cities) were considered our hybrid technology came out as the clear winner with 2-4% lower life cycle cost for the average bus. This is when the discussion started to make the hybrid our standard product for the low floor city segment. Should we really risk being the only one of the “big five” bus manufacturers that did not present a diesel city bus for Euro VI? It seemed to be a very high risk. Then again the facts spoke for themselves. And, the more the options were analyzed the more the rational to spend development resources on the old diesel buses was questioned.

Once we decided that the hybrid would no longer be an option among others but the base technology for our city buses, we could release a lot of resources that elsewise would have been required to squeeze the old diesel and gas buses into the Euro VI legislation. While it still makes sense to use diesel in more rappid regional traffic with higher average load, where we still offer the diesel alternative also for Euro VI. First we needed a brand new engine fully developed to be combined with hybrid drivetrains. The new engine development has enabled further reduced service cost and further efficiency increase simultaneously, and the baseline is of course Euro VI emission performance.

Next, in order to secure the full range we needed to make an 18 meter articulated hybrid bus, this was not a part of the offer in 2010 and therefore a new development was required. The articulated hybrid bus pose several challenges when it comes to drivability. As for the 12 meter buses we have succeeded in increasing the passenger capacity a lot, by the hybridization. Initially we were very cautious not to cause excessive ageing of the batteries, and we still are. The experience is very positive and we now dare to increase the power outtake further to the benefit of drivability and performance. This and a lot more has been enabled by focusing our resources on developing the hybrid technology.

 

Volvo 7900 Hybrid Articulated

The Volvo Hybrid Articulated bus is a new workhorse for the European market. The fuel saving is at least 25% and higher depending on traffic.

Volvo has a history of taking rational decisions when it comes to new technology. In 1959 Volvo was the first car manufacturer to make seatbelts a part of the standard offer, for the legendary Volvo Amazon. In 1976 Volvo introduced the three way catalyst as a standard offer for the cars in the United States. This step enforced the new emission legislation in the USA. How it came to take 13 years until an emission legislation enforcing three way catalysts entered Europe is still beyond my understanding. Who would today question the rational in those decisions?

The 31st of December in 2013 Volvo will make hybrid the standard offer for city buses in Europe.

This is the short version of the story about how the hybrid technology became the standard fit for city buses. Someday, I might write a book about the full story…

*Forced, because when our former CEO Leif Johansson in 2005 promoted the decision to industrialize the hybrid technology, very few suppliers were ready to support the development and we were hence left to do most of the work in-house. A motivated team of coworkers at Volvo Buses and Volvo Powertrain in Göteborg and in Lyon, did not hesitate to take on the challenges that realized the award winning technology that now is our technology base.

 

About volvobuses

Adjunct Professor of Catalysis at Chalmers University of Technology. Lives in Gothenburg, Sweden, with my wife and three daughters born in 1991, 1994 and 1997. Is a passionate runner with a half marathon personal best of 1.24.
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