Wednesday, April 22, 2009

Earth day: NOx, electric cars and diesel

I was listening to Robert Evans from Cenex, a company developping fuel-cell and "low carbon" (whatever that really means) technologies in this podcast on

He suggests electric cars are THE solution (he would says that, would he not?) as they cut pullution. The interviewer doesn't buy this and questions if it's not just moving the pollution to coal fired plants (in the UK between 60% and 33% of the electricity is generated from coal and the 74% from fossil (can't seem to cross-reference 2 sources), 49% of electricity is made burning coal in the US, while in France 78.1% comes from nuclear in 2006).

Evans answered that moving the CO2 emission from tailpipes up to a power station chimney reduces NOx emissions. Which brings the whole issue I've been raising about diesel.

The goverment has been focussing solely on CO2 emissions, via car tax bands linked to emissions for instance (note that airlines and ships are exempt of fuel duty), which had the effect to favour diesel cars: oil burners registrations have grown from 13.8% in 1999 to 43.6% in 2008!

The problem is while diesel engines emit less CO2 (about 20-30%), they emit much more NOx and particulates, about 24 times more according to this source. While CO2 is not an actual pollutant, NOX and particulates are and are harmful to anyone in the vincinity of traffic -in particular children in urban environments.

Just another proof that the government is using CO2 as an excuse to tax with no proven ecological reasons.

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