Carbon Footprint for buses

Nowadays, many cities and transport providers asks for carbon footprint data. By that they usually want to know which carbon dioxide emissions are emitted during operation. Often, the routs and the bus types are known and sometimes data is available for the real fuel consumption.

To make long story short, some examples that have been calculated from statistics from our customers and partners are:

	Average bus kg CO2 /100 km
Volvo 7700 Euro IV City 2	123
Volvo 8700 D7 Euro IV City 2	112
Volvo 9700 Euro IV Commuter 2	80
Volvo 9700 Euro IV Commuter 2 with I-shift*	71
Volvo 7500 Euro IV Biartic City 2	188
Volvo 7500 Euro IV Biartic BRT	122

* The Volvo I-shift gearbox.

When calculated per passenger km the following table is achieved:

Values in g CO2 per passenger km	Number of passengers
	10	25	50	80	120	160
Volvo 7700 Euro IV City 2	123	49	26	17
Volvo 8700 D7 Euro IV City 2	112	46	24	16
Volvo 9700 Euro IV Commuter 2	80	34	18
Volvo 9700 Euro IV Commuter 2 with I-shift	71	30	16
Volvo 7500 Euro IV Biartic City 2		75	40	26	19	15
Volvo 7500 Euro IV Biartic BRT		49	26	17	12	10

If you compare to an average European car with one passenger the CO2 emission is 170 kg/km. With 5 travellers the emission becomes 40 kg CO2 / km.

An environmental car in Europe emits 120 kg CO2 / km. They are mostly 4 seated and with a full car with 4 passengers the emission per traveller becomes 34 kg / km.

The bus stands out as a superior choice!

 

“Appendix”

Or, if you like to make calculations based on your own data it is easy to estimate the carbon footprint by carbon dioxide emissions (kg/km):

Fuel consumption (FC): litre per km

              By measurement of the fuel consumption of your rout.

             or

             By approximation

                        Bus type and Typical rout

                        For example by using the first table above.

Fuel type carbon content (CC):

               European diesel: 0.71 kg carbon per litre

               Environmental diesel MK1: 0.70 kg carbon per litre

               Biodiesel RME: 0.47 kg fossile carbon équivalents per litre (using the keys of the proposed EU energy directive)

The formula that you use is given by:

Carbon dioxide emissions (kg)km) = FC * CC * SF

SF is the stochiometric weight increase per carbon atom: (12+16+16)/(12) = 3.67

             12 g per mole carbon atoms

             16 g per mole oxygen atoms

Fuel consumption, heavy in Life cycle analysis

I frequently get questions from customers, authorities and students about life cycle data for our buses. Since some time we calculate LCA data for new models.
The Life cycle data is used to present an environmental product declaration (EPD):

http://www.volvo.com/vce/vebiz2webauthor/sharepoint/docfetch.aspx?docID=90&listID=a560d670-9b7a-40ff-845b-f34973fc7493&area=VolvoCom+Volvo+Group

Evidently, the fuel consumption of the bus is the single most important factor influencing the environmental load. With Euro IV the impact of emissions decreased considerably.

 

We feel that the EPD confirms that our strive to a market leading position in bus and coach fuel economy, also strengthen our core value environment.
 
In addition, Volvo Truck Corporation displays an efficient tool for calculating the environmental load for transportation of goods. It is also very usefull for understanding the factors influencing the environmental load:

http://www.volvo.com/trucks/global/en-gb/aboutus/environmental_care/Environmental_Product_Declaration/epd_calculator.htm
 

US Climate Security Act

The cost estimate of the proposed Climate Security Act was recently published.

http://www.cbo.gov/ftpdocs/91xx/doc9120/s2191.pdf

In brief, the proposal includes a cap and trade programmes. EPA sets yearly limits and the permits for CO2 emissions are auctioned. The programmes are proposed to be in effect over 40 years.

New Volvo BRT bus in Mexico

Recently, my environmental Volvo colleague in Mexico, Jorge Suarez, brought my attention to the following link.

http://www.portalautomotriz.com/content/2/module/news/op/displaystory/story_id/6510/format/html/

The Volvo 7300 now comes in two new versions; one articulated and one bi-articulated. The longer version of 25 meters has a passenger capacity of 270 people.

There are many advantages, such as high capacity and high throughput of people that match the highest demands for public transports, all categories.

Mexico’s 7300 BRT EU-IV meets the new Mexican Euro IV legislation and will be available within shortly. Environmentally it’s a hit. The simultaneous increase of capacity and improvement of the emission performance to Euro IV realise more than 70% improvement per passenger kilometre.