London To Stop Buying ‘Dirtiest’ Diesel Buses And Switch To Zero Emission

DEC 22 2016 BY MARK KANE 26

New London Mayor, Sadiq Khan is continuing his city’s policy of making public transport cleaner.

With already more than 70 zero emission buses, London is preparing for another major shift with two goals:

  • No more new pure diesel double-deckers added to bus fleet from 2018
  • All new single-deckers for central London to be zero-emission
First pure electric double deck buses on streets of London

Pure electric double deck bus (BYD) on streets of London

In this case, zero emission means all-electric or hydrogen fuel cells.

As a point of interest, the world’s first double-decker hydrogen bus was recently unveiled by Wrightbus (and is pictured below).

“The new hydrogen double-decker is at the forefront of green technology and will be trialled on London’s roads next year.

It is made by leading UK bus manufacturer Wrightbus and forms part of the Mayor’s plan to transform the capital’s bus fleet by phasing out the oldest and most polluting diesel buses, and making the entire fleet ultra-low or zero emission.”

Wrightbus - zero-emission (hydrogen) double deck bus

Wrightbus – zero-emission (hydrogen) double deck bus

The Mayor of London, Sadiq Khan, said of the changes:

“I want London to become a world leader in hydrogen and electric bus technology. I’m implementing hard-hitting measures to clean-up London’s toxic air and it’s great that more cities are getting on board to phase out the procurement of pure diesel buses which sends a clear signal that only the cleanest technologies are wanted in our cities.

“Transforming London’s bus fleet by accelerating the introduction of zero-emission buses is important and I plan to work with bus manufacturers, other cities, the European Commission and the C40 Climate Change Leadership Group of Cities to move this agenda forward.”

Mike Brown MVO, London’s Transport Commissioner added:

“We’re determined to make our public transport system one of the cleanest in the world and phasing out diesel buses lies at the heart of this. Zero emission buses are the future, and my staff are working hard with manufacturers and bus companies to make them a reality in the Capital as quickly as possible.”


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26 Comments on "London To Stop Buying ‘Dirtiest’ Diesel Buses And Switch To Zero Emission"

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Would like to know where they get their hydrogen from. Congrats London.

Do you even need to ask? There’s only one cost-effective source of hydrogen and that’s petroleum (natural gas).

Natural gas from fracking is one of the cheapest energy sources in North America for everything – electricity, heat, whatever. Not so cheap in the UK, but may be acceptable sometimes.

Still, reforming nat. gas to produce hydrogen is relatively clean process, much cleaner and more efficient than burning the same gas in power plant.

Plain old electrolysis is also cost efficient with regular 50 kWh/kg electrolyzer and off-peak or non-dispatchable and useless for grid wind/solar electricity. Average wind PPA in US was around $0.02/kWh with subsidies or $0.04/kWh without subsidies, it means $1-$2/kg electricity for H2 production, and electrolyzer capital cost is not so significant. So nat. gas “cost-efficiency” is not so great, especially that for PEM fuel cell use you would need extra hydrogen filtering if you use methane reforming.

Off-peak solar? What is that?

And I’m not sure how you think transforming natural gas to hydrogen and then oxidizing it is any better than burning it directly. I guess you’re referring to NOxes? Because the rest of the process is less efficient and thus more polluting. Are you trying to claim you’re going to use CCS and make that cost-effective too?

I didn’t tell “off peak solar”. I mean any off-peak electricity, and solar/wind electricity in addition. “And I’m not sure how you think transforming natural gas to hydrogen and then oxidizing it is any better than burning it directly. I guess you’re referring to NOxes?” Yes, NOx. While natural gas combustion emissions are much lower than coal, they are not non-existent. “Because the rest of the process is less efficient and thus more polluting.” Average natural gas power plant in the US is some 30-40% efficient and is not replaced every few years with latest & greatest most expensive model. Plus you have losses in transmission and distribution lines. Fuel cells are 50-70% efficient. That is if primary source of energy is natural gas. If it is non-dispatchable wind/solar, you need to store much of the energy first before charging car battery, balance and maintain expensive electric grid, and it ruins all battery efficiency advantage. Electricity price increase from $0.04/kWh wind PPA to $0.13/kWh average residential illustrates it well. Vehicle manufacturing cost and ability to achieve required range is another factor that is more important than savings/losses on fuel that may be marginal in the whole TCO. “Are you trying… Read more »

I was stuck following a large diesel pick up truck up a two land mountain road, and that thing was emanating all kinds of odors, even dropping back about half a mile. Battery, hydrogen, even burning natural gas or gasoline would be preferable. Glad they’re making the switch. Anything but diesel!

I, my daughter and grandson have asthma (caused by air pollution) and have the same problem, I avoid driving on busy highways with trucks (and trains). The WHO published a report that 7,000,000 people die prematurely each year from air pollution – 80,000 in USA – 8,000 in Canada. Diesel and coal are the major contributors.

Against Asthma and many other things take high doses of Vitamin D3 plus Vitamin K2,
helps al lot!

More info on
and in the superb book of Kate Rhéaume-Bleue “Vitamin K2 and the Calcium Paradox”
and in many videos on Youtube.

One of the main slap-down arguments for EV naysayers in the UK has long been the (apparent) truism that the National Health Service of the UK spends several billions of £, annually, treating respiratory diseases caused (again, apparently) mainly by smog. If true, this would go a long way to explain the apparent disadvantage to UK PLC’s finances by the government encouraging the uptake of EVs (of whatever size) due to lost fuel tax income (currently about £26b pa).

I hate driving behind a diesel anything. My wife would say, but they are using the new clean diesel engines. I’d say, OK, but I can still smell the horrible odor. I wonder if the emissions cheating had anything to do with that or if “true” clean diesel doesn’t stink like the old smelly diesels.

There’s no such thing as “clean diesel” … due to their high compression engines (banned for gas cars decades ago) that emit Nitrogen Oxides (causes asthma, emphysema…) and particulate matter (soot – causes the equivalent of Asbestosis – lungs get scarred and can’t exchange oxygen).

“Clean Diesel”

It’s false and misleading advertising, which I can’t believe they got away with, and continue to get away with. It’s criminal!

Clean diesel and clean coal are both lies.

Maybe it’s a clean coal bus instead. 🙂
Seriously though, a modern diesel with an aftertreatment doesn’t smell worse than a gas vehicle with a catalytic converter–my experience as a bicycle commuter. The modern systems require urea to treat the NOx and the vehicle goes into limp-home mode when the urea runs out until it is replaced. They can greatly reduce the PM, but not eliminate it.

Diesel is not clean.. those who believe their is, news flash.. it isnt.
Do not breathe in Diesels exhaust if you can avoid it. Congrats to London, hope other cities will follow, and the quicker the better. Lived in the centre of Sydney for quite a few years, and got to know a guy who measured the air, tight outside my office – interesting discussions for sure about diesels.

I don’t think you can smell ultra-fine and PM2.5 particles at all, but they are the worst. In particular ultra fine particles that can penetrate blood-brain barrier and by some hypothesis may be related to Alzheimer’s. Sure modern diesels are much better in theory, but they are still far from fuel cells that just clean outside air, which is quite bad in places like London. In practice though you know, EU is planning to start on road diesel testing in 2017-2018, for well known reasons.

Run on High Performance Renewable diesel, HPR is a bio synthetic, no refinery residue.

It is great that if it is sustainable, but it doesn’t eliminate local emission problem in cities.

HPR is some kind of brand name. It’s better that you call it HVO (hydrotreated vegetable oil).

So that we know that we talk about the same thing no matter if it’s the HVO from Propel that they have branded HPR (which is just rebranded HVO from Nesté) or the HVO from Nesté that they have branded Nexbtl or the HVO from Preem that they have branded Evolution Diesel etc.

It’s a great fuel though, which we should use on all the diesel buses/trucks/cars that we have not replaced yet with electric versions.

In Sweden 25% of all diesel fuel is renewable and HVO100 (100% HVO) is getting increasingly popular.

GO LONDON GO…don’t become another toxic and poisoned Beijing.

At this present moment, with battery powered bus still far from economical, better to go with natural gas powered bus instead.

Economics is not everything. Clean air and the environment is more important.

But in a study made in Sweden battery electric buses were the cheapest option over three years ago already.
The gas bus was the most expensive option.

The situation in the UK is very similar when looking at the most important factors like fuel prices, electricity costs etc.

So it’s very likely that the TCO is lower for battery powered buses in the UK too. Especially when compared to a natural gas powered bus, which can’t even compete with diesel buses on economic grounds.


Albuquerque, NM is purchasing a fleet of BYD evs.