Welcome to our final blog post on electric cars, in which we’ll be dealing with a couple of questions over the general sustainability of the vehicles, as well as getting the rest of your questions answered that we haven’t managed to get into previous weeks.
Next week, we’ll be bringing you a list of questions that we’re preparing for our next topic, Retrofitting Sustainability, and you’ll then have time until a couple of weeks after Easter to give us your questions to add to the list.
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This week, we’ve again spent time with Professor Phil Blythe, along with members of his research team, PhD student Andrew Robinson and Research Associate Graeme Hill, and put our last few questions to them.
Dr Sarah Sweeney, Theme Administrator, NIReS: So, this is our last session in this series, and I want to start off by thanking all of you again for taking the time each week to sit with us and share your knowledge and expertise: it’s been really invaluable.
Phil: You’re very welcome Sarah.
Sarah: So to kick off this session, we’d like to address a couple of questions on the overall sustainability of electric cars compared to conventional petrol/diesel vehicles. Firstly, a question that we’ve heard being raised a few times – isn’t it a ‘false’ sustainability to use electric cars at the moment, when the electricity used is derived from fossil fuels?
Phil: That’s a very good question, and one that I’m not surprised people are wondering about. Obviously, if we had a source of electricity which wasn’t derived from fossil fuels then the benefit of using electric vehicles would be far clearer. But even once the source of the electricity has been taken into account, the carbon dioxide emissions per mile for an electric vehicle are less than even the ‘greenest’ petrol car. However, the main benefit of electric cars in terms of sustainability is that they produce no harmful emissions at the tailpipe, whereas petrol and diesel cars produce particulates, volatile organic compounds, hydrocarbons, carbon monoxide, ozone, lead and various oxides of nitrogen. Electric cars can therefore contribute to making the air in cities much cleaner, and this is their main environmental benefit. Their overall environmental impact will depend on the source of the electricity used to recharge their batteries. A study made in the UK in 2008 concluded that electric vehicles had the potential to cut down carbon dioxide and greenhouse gas emissions by at least 40%, even taking into account the emissions due to current electricity generation in the UK and emissions relating to the production and disposal of electric vehicles (and more information on this is fairly widely available online).
Sarah: And what about the production of the cars in the first place? How sustainable are the production processes and materials used in EV production compared to that of conventional cars?
Graeme: Generally, unfortunately, the production processes for electric cars are no more sustainable than those used to produce conventional cars.
Sarah: And our last question, again from Steve is about our most recent blog post. He asks: ‘in one of Andrew’s answers he said that “Using fast-charging points will significantly reduce the battery life”. However, Professor Blythe said recently that:”Fast charging does not seem to reduce life of battery as much as previously feared.”. Is that the same answer expressed in different ways or is there a difference of opinion here? Either way, how much does each fast charge take off the battery’s life?’
Andrew: I think we’re just talking about a difference in context between the two statements. Phil was answering a question about the length of time to charge up a car versus the impact on battery life, and had mentioned that fast charging doesn’t seem to reduce battery life as much as had at first been suspected which is certainly the case. Manufacturers, for example Mitsubishi, state that one fast charge a day will not impact significantly on the battery life and there is no evidence to suggest that drivers are using fast charges more than once a day. Under these conditions the battery life of the vehicles was not affected as much as feared. However, and I think this is what I was highlighting, manufacturers have not said that exclusively using fast chargers multiple times a day will not damage the battery so over-reliance on fast charging may well have an impact.
Sarah: Fantastic, thank you all. Once again, many thanks for taking so much time and effort to answer all of our questions – I think you’ve really shed some light on what it would really be like to own and drive an electric car, and hopefully our readers are now better informed on the subject.