Calculation of CO2 reductions
The Alcosuisse calculation of CO2 reductions is based on:
- comparative emissions of essEnce5 and 95-octane petrol, carried out by EMPA in 2002 on a popular vehicle that had not been altered in any way, based on a recognised test cycle (NEDC, New European Driving Cycle)
- a life cycle assessment, carried out by the Laboratory of Energy Systems (LASEN) of the Federal Institution of Technology in Lausanne (EPFL), which takes account of all the stages, from production of feedstocks through to transportation of the bioethanol fuel to its blending site.
- the net volume calorific values of 32 MJ/litre for petrol and 21.285 MJ/litre for ethanol (anhydrous)
The main finding of the EMPA test with respect to CO2 emissions is the 1% reduction in fuel consumption for the same driving performance. This figure is confirmed by several other international measurement programmes.
The following table is based on the EMPA consumption measurement and the comparative life cycle assessment of the bioethanol chain:
- Comparison of greenhouse gas emissions from 95-octane petrol and essEnce5
Under identical conditions (100 km covered according to the NEDC), the test vehicle, overall, produced 3.9% less CO2 with essEnce5 than with 95-octane commercial petrol.
This 3.9% corresponds to a reduction of 0.821 kg CO2eq/100 km, i.e. with a fuel consumption of 7l/100 km, to 0.821 / 7 = 0.118 kg CO2eq per litre of essEnce5.
If all petrol used in Switzerland was essEnce5, i.e. 5,100 million litres, the reduction in CO2 emissions would be 0.118 kg CO2eq/l essEnce5 x 5,100 million litres of essEnce5 = 601,800 tonnes CO2eq.
