Driving Quality of Life

Archive for March, 2012

One bus = 50 cars

Last week I visited Montreal. The week before a $73 million project on electro mobility was announced by Quebec Government and Nova Bus is one of the partners.  (read about it here)

This legendary Nova LFS bus announces that a load of proud bus riders are equal to 50 cars in environmental load!

It is very encouraging to see how authorities around the world takes increasing responsibility for the development of the emerging electric bus technology.

In spring time when I go jogging over the weekend I often take a detour to check the status of the blue Anemone that mostly is one of the first flowers that appear where I live in Sweden. And now, the time has come. The very first flower was observed already the 11th of March but the real burst out was last weekend.

Life cycle swamp

I have been warned by experienced colleagues not to get caught in the life cycle swamp. Still, analyzing well-to-wheel efficiency is very useful in order to understand how different energy sources are used most efficiently.
It works in both directions.

For example: For an energy user it is possible to calculate which energy provider gives the lowest environmental impact.
For an energy provider it is possible to find how the energy is best used.

Most often, it is found in the first round that we all should use hydro power. But the limited availability of the most environmentally friendly energy sources makes the task more complex. This means that we need to find different energy sources for different users.

This is when I mostly get stuck. However, we know that decreasing the energy use should always be right, independently of which energy source we use.

We know that the energy use of an average European city bus is:
Diesel: 5.00 kWh/km
Gas: 6.55 kWh/km
We calculate the electric bus energy use to be: 1.4 kWh/km.
No doubt, it is better to run a bus on sustainable electricity than on diesel or gas. But, this is no surprise.

Now lets turn the question around. If we start from biomass, which route gives the highest efficiency?
Biomass -> Gasification -> Biogas -> Gas Bus
Biomass -> Gasification -> Biogas -> Electricity -> Electric bus

According to my calculations the detour via electricity turns out to be more favorable.

But there are many uncertainties. I would therefore like to challenge anyone reading this blog to provide data or references for the well-to-wheel calculation for gas buses running on biogas from generic biomass, and for the corresponding electric bus running on electricity generated from generic biomass (preferably via gasification).

Biogas route
Well-to-tank efficiency is: 54%
Tank-to-wheel efficiency is: 17%

Biogas-electric route
Well-to-tank efficiency is: 39%
Tank-to-wheel efficiency is: 75%

Hybrids to Hamburg

Hamburg and affiliates have recently bought Volvo hybrid buses. When I visited the area recently there were by coincidence eight of the buses standing in the court of the Volvo workshop in Hamburg.

The transport authority, Hamburger Hochbahn, is probably the most reputed transport authority in Europe. The track record is impressive with increased attractiveness, an increasing share of public transport users and at the same time with enormous efficiency. A bit more than 50% of the daily users choose public transports. The cost coverage in 2011 was 88.7%.

No doubt both cost efficiency and attractiveness were important factors in the decision to purchase Volvo hybrid buses.

Image

Four of the Volvo Hybrids on their way to be delivered to Hamburger Hochbahn.

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