As the Green Party support this technology yet obviously shouldn't, I've been having correspondence with them about it. First up was MEP Caroline Lucas.
London's about to have a new larger hydrogen vehicle trial, so I've had exchanges with Darren Johnson and Jenny Jones, the Green members of the London Assembly, as they are supporting this high-carbon technology. So the second exchange was with London Assembly member Darren Johnson
After that, the other Green London AM Jenny Jones, who table some questions to the Mayor, Boris Johnson.
Darren Johnson (no relation, you've gotta hope) has forwarded the answers.
Please find below the response from Boris Johnson, The Mayor of London to the questions that Darren Johnson, Green Party Member of the London Assembly raised on your behalf at the September 2008 London Assembly’s Mayors Question Time.
Hydrogen Buses, Question No: 1694/2008
Darren Johnson’s questions:
Will the mayor respond to the following questions from a member of the public:
- With the planned expansion of the trial of hydrogen buses going ahead this year, will you ensure the hydrogen is from renewable sources?
- What is the target for improving on the well to wheel calculation of CO2 emissions obtained from the previous CUTE [Clean Urban Transport for Europe, the pilot project that ended in 2006] trial?
- With the expansion of the existing scheme to encourage local authorities to install charge points for electric vehicles, what efforts are being made to ensure that this energy is from renewable sources?
- Will you carry out an assessment on the full potential for sewage in London to be used as a fuel for Combined Heat and Power generation, or for the bus fleet?
Boris Johnson’s response:
The new hydrogen buses will be on London’s roads by 2010. The hydrogen used will be produced by steam methane reforming. TfL [Transport for London] and Air Products (the refuelling supplier) are committed to putting in place measures that minimise the emissions from this method over the life of the projects as further advancements in abatement technology become available. In the future, TfL will look to procure hydrogen from the greenest sources and harness renewable technologies when they become available and are viable.
No well-to-wheel statistics were produced for the CUTE trial. TfL expects the new generation of buses to produce significantly lower emissions with the fuel-cell buses estimated to produce 50% less CO2 than a diesel bus on a well-to-wheel basis. These figures can be improved further when greener sources of hydrogen are developed.
TfL and GLA officers are in discussions with local authorities and energy suppliers to investigate the possibility of obtaining electricity from renewable sources.
In terms of building facilities, TfL have introduced combined heat-power generation to their newest building. This technology can be adapted to run on gases other than mains natural gas, should potential alternatives such as sewage become available. In terms of buses, current hybrid technology being trialled in the bus fleet offers immediately realisable CO2 benefits in London.
'No well-to-wheel statistics were produced for the CUTE trial'? Come with me to page 79 of CUTE's own report on their trial, where we find this chart.
The baseline is the impact of a normal diesel Mercedes Citaro bus, the same model that the hydrogen bus trial adapted.
To decode, the three groups are:
FC H2 St.ref. - fuel cell bus, powered by hydrogen from steam reforming (ie natural gas)
FC NEBUS, H2 St.ref. - the NEBUS, the hydrogen Citaro's predecssor, powered by a fuel cell with hydrogen from natural gas.
FC, H2 Hydro - fuel cell bus powered by hydrogen made from electricity from hydroelectric dams.
The four bars on the graph are:
PE (n.ren) - Primary energy from non-renewable resources
GWP100 - global warming potential (taking all climate impacts into account, not just CO2)
POCP - Summer smog formation potential
AP - Acidification potential
It clearly shows that the energy and climate impacts are substantially worse with the hydrogen bus when powered from natural gas.
Incidentally, as I said in my original piece, the hydroelectric thing is a red herring. Firstly, there's the way that hydroelectricity is seen a climate-neutral whereas it emits huge quantities of methane (a greenhouse gas 25 times as potent as CO2).
Beyond that, there is - as with all the 'hydrogen from renewable sources' stuff - the fact that it displaces electricity from fossil sources. I know I've said it before, but it seems that either I'm missing summat or else people are refusing to hear me.
If we earmark our renewables for this new electricity demand, they no longer feed the grid. So more fossils get burnt to make up the shortfall. It only works if the grid is entirely powered by renewables with capacity for all our present uses and our vehicles too.
Full marks to the Greens for their tenacity and responsiveness, it really does set them apart from the lower fob-off threshold of politicians in other parties. But they clearly haven't grasped the point of my writing to them, despite reiterations, citing sources and a couple of simple handy metaphors.
Answers that miss the point of questions that, in turn, missed the point are not really going to mean much, are they?
I'm following it up but, as with all the exchanges in this, I'm letting it run until the exchange has ended before I publish so that it's fairer and clearer for all concerned.