Watt is the problem?
From the woman on the Brixton omnibus
With the London Mayoral election in sight, we are hearing a lot about policies to deal with air pollution. We’re not a political blog* - that would get us into the air pollution equivalent of hot water! But it does help to see the issues being aired more than usual.
For instance, the current Mayor, Sadiq Khan (whose book we covered here) has been writing about things he and his team has done while in office. We were happy to see reference to Breathe London, without which we would not be doing this work. But one element we particularly picked up on was the electrification agenda. Our Brixton monitoring node has been showing shocking levels of nitrogen dioxide for months, breaching World Health Organisation limits almost every day. This may be contributing to Louise’s breathing problems - so this is personal.
Hoarse power (cough, cough)
We’ve talked about private electric vehicles before in this blog, but not yet covered electrification of buses. According to Khan’s update, Transport for London has delivered over 1,300 electric buses, making it the largest zero-emission bus fleet in western Europe (here our air pollution pedantry steps in: as our esteemed readers will know, electric vehicles are heavier and so give off more particulate matter pollution, not to mention all forms of pollution used in their manufacture; what they don’t have is exhaust pipe emissions, since they don’t have an exhaust pipe). Khan is quoting C40 cities here - an initiative of which he is chair - which also mentions the decision for all new buses in London to be “zero-emission” and the aim of a completely “zero-emission” fleet by 2034, if not before.
So how are Londoners to tell if this is good enough? The C40 article also states that one in seven buses in London are “zero-emission” - when you put it that way, it doesn’t seem that good, even if it is best in class in western Europe. It’s quite hard to find comparative data (and the C40 article notes that other cities in that network have reported their electric bus levels confidentially so they cannot be quoted). We found a nice article by Sustainable Bus that mentioned the six European countries where electric buses make up over 25% of the network, including the UK. Netherlands is powering ahead of the pack with 81%. The same article also shows that diesel is still shockingly prevalent - around 65% in the UK and comparable countries such as Finland, Denmark and Norway. We spotted that, outside Europe, Shenzhen has electrified its entire fleet, so it is possible.
Why does it seem so hard to electrify bus fleets? One understandable ‘excuse’ is that it probably doesn’t make environmental (let alone economic) sense to scrap existing, functioning buses - so the process will be one of replacement over time. Electric buses are expensive so have to be planned for carefully (however, they are generally cheaper to run). There are a number of companies including KleanDrive which retrofit existing fleets and offer a financing plan.
Much is made of charging infrastructure for private electric vehicles: since buses typically have a specific place where they “go to sleep”, overnight charging should be relatively straightforward (albeit require upfront investment). But this might not be enough for the bus to complete many routes through the day (especially as the battery degrades), so some use wireless technology for quick top ups. This technology could be inserted in roads (say at traffic lights) but we have seen very few examples of this taking hold globally.
Not quite the joule of the crown
It seems that none of the routes going through Brixton are (yet) electric. So aside from electricity, are there any other clean and viable power sources to keep our cities moving?
Hydrogen fuel cells have been around for a while and 20 buses in London are hydrogen powered, but have yet to make a big impact. This article is an excellent review of the state of hydrogen as a way of powering urban bus fleets. The main challenge it identifies is the cost of generating hydrogen and developing the hydrogen distribution network. The World Economic Forum certainly thinks it’s a good, green alternative.
France, Spain and Sweden stand out for the deployment of compressed natural gas buses in city public transport. Louise remembers Delhi showing the way in the early 2000s but it clearly hasn’t led to good air quality. It is seen as a clean alternative but spoiler alert - it’s not.
And finally biogases such as biomethane? Biogas is made when biomass, such as organic waste, manure, food waste, and agricultural residue, is fermented or put through anaerobic digestion. Capturing biomethane generated from waste food prevents the release of greenhouse gases and its production doesn’t involve finding new oil and gas sources. But ultimately it still involves burning hydrocarbons. The Clean Air Coalition says: As an alternative to burning polluting wood, dung, or fossil fuels for household energy, biogas could help slow climate change, improve global health, reduce agricultural losses, increase energy access, and improve people’s lives and businesses.
*As we are not a political blog, we probably don’t need to review everything the other candidates have been saying. We’re looking forward to their manifestos to find out more about their clean air policies, particularly our friend Rob Blackie whom avid readers may have spotted in one of our early blogs. If you want to influence the candidates’ policies, Mums for Lungs has a campaign.