Electric cars – are they really green?

Is a question the Electrifying team are frequently asked. So here are our thoughts. 

Tom Barnard

4.3.2020

Most of us agree that electric cars are better for the environment, right?

But on the other hand, we’ve all seen the reports that question this. Maybe asking if batteries are a good use of precious metals, or if the electricity they use is being generated in a responsible way.

So what’s the low down? Sadly there isn’t a simple answer. I know, irritating isn’t? I’m not a fan of sitting on the fence and I doubt you are either.

But the arguments around electric cars are complex and we’d encourage you to do your own research to help you understand the arguments. 

For starters look at the sources of information. Is the news article or post balanced and from a source you trust? If it quotes a report, who wrote it and how are they funded? 

There’s a lot of dis-information floating around in today’s connected world and checking out the sources of facts and opinions is a great habit to get into.

There are a great number of people and businesses who feel threatened by the growth in electric cars and they’re not necessarily offering the most objective view. While some environmental pressure groups can go too far the other way with unrealistic demands.

Whether you are looking to really understand how you can reduce your carbon footprint or just want to have an answer for the arguments you’ll hear in the pub, then we’re here to clear the air. 

The team at electrifying.com have been studying electric cars and the infrastructure that supports them for over a decade and like to think we can offer a balanced view. So read on, we hope it helps!

Are electric car batteries bad for the environment?

Making anything has an environmental impact, and an electric car battery isn’t made of compressed daisies and organic hemp. In fact, there are some precious metals in batteries which can only be extracted from deep in the ground, often in countries which have dubious records for environmental protection and health and safety. Add the fact that batteries are notoriously tricky to recycle and suddenly an electric car might not seem all that green after all. 

But the argument for the defence is pretty strong too. Firstly, extracting, refining and distributing oil to make petrol and diesel has a huge environmental cost, and that’s before the fuel has been burnt in the car. Also, car makers are aware of the issues around sourcing battery ‘ingredients’ and go to some lengths to ensure that their suppliers are ethical, big business wants to avoid bad PR at all costs!

As for recycling, car makers have other ideas about how to reuse batteries rather than tearing them apart and disposing of the parts. Which is what happens with a conventional engine at the end of its life. 

When an electric car’s power pack is no longer needed, the manufacturer will buy it back and use the whole unit or the individual cells to make other batteries for use in homes and businesses. These store power from renewable energy or charge up when the power is cheaper at night and release it when it’s more expensive or there is a power cut. Nissan is even creating small battery packs using old Leaf cells which can take the place of a petrol generator on a boat or in a caravan.

In the future, the pace of battery technology is moving fast as portable power is needed for everything these days from headphones to helicopters. Scientists are working hard to find ways of making batteries which won’t need as many precious metals, will be cheaper, lighter and will have an even longer life. If you need an indication of the pace of change, the first Nissan Leaf had a 24kWh battery in 2011. It’s now available with a 62kWh pack which is the same physical size. 

It’s also worth remembering that a conventional engine isn’t an easy thing to make either and will need maintenance such as oils and filters throughout its life. 

Can the national grid cope with the increase in electric cars?

The battery in a ‘normal’ electric car like a Kia e-Niro can hold enough energy to power a three-bedroom house for over a week. So it’s easy to see why some people are worried about the effect of all these electric car buyers suddenly wanting all this power at once. Drivers could come home, plug their car in and then turn on the oven for dinner, switch on the kettle and flick on Coronation Street all at the same time. Multiply that by an entire town and you can see the issue – there will be a ‘rush hour’ on the electricity supply.

To avoid blackouts, the boffins have been working on ways to manage supply so that electric cars can become part of the solution rather than the problem. The first way is to manage demand using pricing, which is one of the reasons that we are all getting smart meters installed in our houses. Instead of charging straight away when you arrive home, EV owners will use the built-in timers in their cars or on an app to switch on the flow when the energy rate is at its lowest, usually in the middle of the night. 

Electricity companies are very keen for this to happen as there is currently very little demand for power at night, but conventional electricity generating stations can’t just be shut down for a few hours and will continue producing power even if it’s not needed. At the same time, wind, wave and hydroelectric generation continues too and there is often a surplus of power created at night which electric cars can soak up neatly.

The next stage is the really clever part and is called vehicle to grid. When you plug your car in, the charging unit will be talking remotely to the energy supplier’s computer and working out the best time to charge. But it will also allow the energy which is already in your battery to flow back the other way into the grid to help support the local electricity supply in times of high demand or an emergency (such as a power cut).

By having this flexibility to smooth the peaks and troughs in demand for power on the grid, power stations can be made more efficient and we can make better use of renewables.

You might not like the idea of the grid ‘stealing’ the power from your battery, but the systems will learn when you are likely to want your car to be charged (for example, it will know you leave for work at 7.30am and will ensure the battery is full for that time). There will also be other incentives, such as very cheap or even free power for anyone who takes part. Pilot schemes are already in place using Nissan Leafs.

What about hydrogen?

As an alternative to battery electric vehicles, some car makers are backing fuel cells instead. This tech has been used for many years, most notably in spacecraft, while I first drove a fuel cell powered Honda back in 2003. A hydrogen car still uses an electric motor, but instead of being powered by a battery it makes it’s electricity by harnessing the energy created in the chemical reaction when hydrogen and oxygen are mixed.

The really good part is that the only exhaust emission is pure water and the fuel tank can be refilled in a matter of minutes, so it takes barely longer than filling up with petrol or diesel as we’re used to.  The range is about the same and as they don’t need a heavy battery, the car itself is lighter than a conventional electric car.

The downsides (of course, there are always those!) are that fuel cell cars like the Hyundai Nexo and Toyota Mirai are rare and expensive, and there are currently only about 10 refuelling stations in the country.  The actual fuel itself has to be manufactured too. In some countries (notably South Korea) there’s lots of hydrogen which is created naturally as a by-product of other industry and so it is essentially a ‘free’ fuel. It then has to be transported to the UK though, usually in large specialist ships. 

The alternative is to produce the hydrogen locally by passing electricity through water – essentially a reverse of the chemical reaction which takes place in a fuel cell car. This process can be done using renewable energy and can therefore be considered ‘green’, however it’s not terribly efficient as almost half of the electric energy is lost in the process of changing electricity to hydrogen and then back again.

The real opportunity for fuel cells is with large, heavy vehicles like trucks, buses and trains. These can have dedicated refuelling facilities at a depot and also have more space to house the storage tanks which are needed to store hydrogen safely at high pressure.

What about the electricity itself?

It’s a common complaint that electric cars simply transfer the pollution from the exhaust pipe to a power station chimney. Even if that was true, it wouldn’t be a bad thing, as power stations tend to be in less-populated areas. Emissions are never good, but they are slightly more acceptable when they are not concentrated into urban areas which are full of people. Even a die-hard petrol head would have to admit that they’d rather an electric car was passing their children’s school than an old diesel.

But the reality is that the electricity supply is cleaner than you might expect and is changing rapidly. The mix varies according to the season and factors like how windy (or sunny) it is, but official figures show that only around 0.3% of our power comes from coal these days. Burning gas is creating about a third of our electricity with nuclear coming in at about 12% on average. Wind and solar are currently about 20% and bioenergy (burning wood) is another 8%. We also import about 5% from abroad, typically from France, Holland or Ireland. The French have a pretty green grid, with only about 4.4% of their power coming from non-renewables. The Dutch and Irish aren’t so green, sadly.

Various studies have calculated a CO2 grams per kilometre emissions figure for electric cars based on the amount of carbon dioxide emitted by the power stations and the distance a unit of electricity will move a car. These are almost all lower than the equivalent petrol or diesel figure and they don’t even consider the electricity and other fuels which are used to refine and distribute gasoline products before you pour them into your car’s tank.

There’s more good news for electric cars. The UK mix of electricity generation is changing rapidly, and is becoming greener all the time. So using an electric car will become more environmentally friendly as the car gets older, while a petrol or diesel car will always pollute the same amount.

What about other emissions from tyres and brakes?

This is a really interesting one, because when the exhaust emissions from internal combustion engines have been removed from urban areas there will be another focus on improving air quality by removing the dust (called particulates) from tyres and brakes. That black coating which appears on your wheels is only part of the story, most of the dust is released into the air where it coats buildings and is inhaled by unfortunate passers-by. 

All vehicles create this, but there has been some speculation that electric cars may create more particulates from brakes and tyres as they tend to be heavier than conventional models. 

This is partly true, but any electric car owner will tell you that their brakes wear very slowly because almost all have regenerative braking, where the energy when you slow down is harnessed to put power back into the battery. This means the traditional pads and discs are used rarely and so aren’t producing any dust.

Tyres are trickier, as in our experience they do wear faster on electric cars. It’s partially because of the car’s weight, but also because they produce all of their power from a standstill, which can mean the rubber has trouble gripping for a few moments until the electronics reign them in.  You can be sure the tyre makers are working hard to make sure there is an answer to this particulate problem; until then, we can only suggest that you take it easy on your tyres when you are in a populated area.

As you can see, there isn’t an easy answer to the question ‘are electric cars really green’. But if you’d really like us to get off the fence, then we believe they are. They aren’t the silver bullet to solve the World’s climate crisis but if you’re able to switch to one, be that a hybrid-electric or full battery-electric then it will have a positive impact on reducing your carbon footprint. And that’s a good thing.

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