A few weeks back I found myself writing a response to an article in the Times newspaper. Someone there had caught wind of the fact that you can now buy a mountain bike with an integrated electric motor, and decided that this was going to bring about the destruction of the British countryside. I said it was a very silly article, and the responses in internet-land were pretty much in universal agreement. However there were also some commenters out there who voiced concerns over the growth of e-bikes on environmental grounds. Taking a low-impact activity like cycling, and adding batteries, motors and electronics into the mix – that can’t be good for the planet, surely?

My disclaimer

Before we go any further, a bit of a disclaimer is required. There’s an assumption that if you work in the cycling media, you immediately lose your objectivity, as you have to stay matey with the bike industry and dutifully promote whatever they’ve decided to inflict on the unsuspecting public this year. This is not the case here. I haven’t had my palm crossed with free T-shirts or press trips. I don’t own an e-bike. And I’ve never been given one to test (as an occasional freelance contributor to this website, I’m way too far down the pecking order for that).

sram e-mtb bosch drivetrain environment green technology

My main occupation at the moment is studying for a Master’s degree in Transport Studies, so while I’m not claiming to be any sort of authority on the subject, I do have an interest. And e-bikes are a really interesting development – a mix of old and new technology that could be a game-changer for short-distance transport, but are viewed with some (justifiable) suspicion by the normally-aspirated cyclists out there.

Technology for transport

As someone who rides bikes for transport, I’m sceptical about complicating a simple, low-maintenance machine with a load of sensitive electronics. And I’ve face-palmed hard during a presentation by an e-bike manufacturer who described its products as “zero-carbon“. So I’ve tried to separate the facts from the hype and look at the evidence out there for what damage e-bikes do, or don’t do, to the planet.

environment battery green technology

Battery Farming

First of all, let’s look at the bad stuff, starting with arguably the worst bit of e-bikes: the battery. Current e-bikes use lithium ion batteries, the same technology which is in your phone, the lights that you go night riding with, your GPS device, and pretty much every electronic gizmo these days.

There are a huge number of Li-ion batteries out there – one report estimates that in Europe, the equivalent of 20 Li-ion batteries for every person are sold every year. And Li-ion batteries are starting to come under increasing scrutiny from an environmental perspective, because lithium extraction is, to put it kindly, a dirty business. It takes place in some of the most arid regions on earth, and involves pumping huge quantities of scarce water into salt flats, or crushing and processing tonnes of rock.

Li-ion batteries need virgin lithium, not recycled stuff, and the recycling rate for worn-out batteries is poor, with some estimates as low as 5%.

The figures don’t tell the whole story though. For starters, just 1% of a Li-ion battery is pure lithium, and when it comes to raw materials with ethical and environmental issues, lithium is by no means alone.

There are huge issues with the way many extractive industries are regulated, and that goes for aluminium, oil and gas too. These can only be addressed by closing loopholes and improving governance. There’s very little point in boycotting e-bikes, unless you’re also going to get rid of all those other items of tech which use Li-ion batteries too.

Low Recycling Rates

Many Li-ion batteries are small, and are built in to the devices they power, so it’s all too easy for them to end up as general waste. The large, removable battery that powers an e-bike has a lifespan of several years, and at the end of this, it’s arguably much more likely to be recycled.

Many e-bike brands are already running recycling schemes, and if you bought your e-bike in a country covered by the EU’s Battery Directive, such as the UK, the manufacturer is required by law to recycle the battery once it’s worn out.

low battery recycle green technology?

Turning to the rest of the bike, it’s obvious that building and charging an e-bike will have an additional environmental impact, as the e-bike is a much more complex machine, with all the same parts as a regular bicycle, plus the electronics and the motor. There are quite a few life cycle analyses of e-bikes out there, and while all these studies are based on some hefty assumptions, the process of manufacturing an e-bike seems to generate 2-3 times the emissions of a regular bike.

The energy used to charge an e-bike once it’s produced isn’t huge though, probably because it’s relatively light (by the standards of a vehicle, anyway) and it’s also partly powered by its rider. In fact one study found that the emissions an e-bike produces in daily use are only 1 gram of CO2 per km more than a normal bike.

Green Technology Transport Trends

Let’s zoom out a bit, away from cycling, and look at transport as a whole. As a society, we’re still massively dependent on vehicles which run on fossil fuels, and a lot of these vehicles are travelling around almost empty, except for the driver. This needs to change if we’re going to stop cooking the planet, but the most popular suggested solution – electric cars – comes with its own problems.

Batteries have a relatively poor energy density compared to a tank of petrol, so fully electric cars (battery electric vehicles, or BEVs, to give them their somewhat maternal industry acronym) are heavier than vehicles with internal combustion engines. This means they need more power to push them along. Electric vehicles are also very cheap to run, which means that they will probably be used more too. And as we head towards 2030, a date which probably seemed a very long way off back when we were setting greenhouse gas reduction targets, our ability to generate all this power in a carbon-neutral fashion is looking distinctly dubious.

If they started to replace cars as everyday personal transportation, e-bikes could reduce our energy consumption dramatically, and free up a load of space in our towns and cities, while still getting people to where they need to be. And there’s evidence that this could happen. Studies of e-bike users have generally found that unless they already have restrictions on car use (for example, students living on campus), they tend to drive less and ride more.

Most travel isn’t long-distance business trips – in the UK, two thirds of all our journeys are less than 5 miles. Swapping to an e-bike ought to be possible for some of these, even for people who wouldn’t think of themselves as cyclists. And if e-bikes became popular for everyday journeys, there could be knock-on benefits for all cycling, such as better infrastructure or more secure bike storage.

environment motor green technology brose

Electric Mountains

What about mountain biking though? Again, if you look at e-MTBs purely as a replacement for your normal mountain bike, they’re worse for the environment. But do you just ride your mountain bike from your door, or do you tend to drive somewhere with it first? If you answered yes to that second question, you’re not alone. At a trail centre or bike park the overwhelming majority of riders tend to arrive by car.

If you have an e-MTB which lets you get to decent trails without driving, that’s a win for your carbon footprint. Another interesting aspect of e-MTBs is that it’s currently very difficult to fly with one, as the batteries (those things again!) are prohibited items on pretty much all commercial flights. If e-bikes took over mountain biking, would we see more local trail development and fewer long-distance trips to exotic destinations? It’s difficult to say, but I’d be very surprised if we carried on riding in the same way as before.

e-MTB green technology

In a green-off with conventional bikes, e-bikes will always lose. But not by as much as you think. And to condemn them as bad for the environment ignores a lot of wider context. If you view them as a substitute for bikes, they’re not a good thing. But if you look at them as a substitute for cars – whether it’s for getting to work or avoiding a drive to a trail centre – the benefits are obvious.

E-bike use is growing at a phenomenal rate, and we still don’t know how this will affect cycling, but based on the available evidence, my guess is it’ll largely be positive. In the meantime, if anyone fancies funding a PhD on e-MTB use, let me know…