advantage of environment

Environmental advantages

      Natural gas vehicles are of great advantage to the environment Firstly, natural gas car CO2 emissions are lower than oil and petrol, contributing less to global warming. Secondly, harmful nitrogen compound emissions ( Nox), are far below European limits.



  Lower CO2 emission CO2 is a greenhouse gas and the largest source of global warming among the human-made emissions. Among the fossil fuels, natural gas makes less CO2 per energy unit. CO2 emissions per kilometer also depend on engine efficiency or fuel consumption per kilometer.

A group of experts chosen by the European Commission analysed cars in the VW Golf category, focusing on the expected development in motor technology. The investigation is a well-to-wheels-study which analyses greenhouse gas emissions, energy efficiency, and costs of 75 different pathways — the whole process from the primary energy source to final use.

  The report concludes that in 2010, natural gas cars are expected to have 22% lower CO2 emissions than petrol cars, and 15% lower than diesel cars. It also concludes that this advantage can be increased by optimising motor technology, since natural gas holds a bigger efficiency potential than the diesel technology. Introducing hybrid cars will still have a great impact.

  Very low NOx emission Emissions are regulated by Euro norms for larger vehicles. The Euro 3 norm regulates current demands but will gradually tighten to Euro 5 norm by 2009. EEV is the Enhanced Environmental Vehicle standard and is the maximum emission for a vehicle if it is to be characterized as friendly to the environment. MAN E2866 DUH 03 is the bus which is used for the demo project, and an illustration of the bus is included as an example of the present standard of natural gas engines.

   Even though emission demands will tighten with Euro 4 and Euro 5, natural gas technology available today is already far below those future limits and also below the even more demanding EEV standard. Natural gas bus NOx emissions are less than 1/5 of the Euro 5 (and EEV) demands, and particle emissions are less than 1/4 of the Euro 5 limit. So despite tightening Euro norms, we can achieve considerable environmental improvements in the future by using natural gas vehicles.

As mentioned earlier, the relation between NO and NO2 is of great importance, and here natural gas busses provide us with an additional advantage, since the NO2 share is less than for diesel busses, both with and without particle filters.