Are electric cars the future?
Posted by NEF Gabby on 23 September 2016 at 12:06 pm
The electric car debate has been a long and contested road, with questions still remaining unanswered about the ability Electric Vehicles (EVs) have to reshape society and replace our gas guzzling needs. Aerospace engineer and Motorsport fan Lukas Willcocks has test driven a number of electric vehicles so we asked him for his views.
Despite suggested benefits, EVs still hold a minuscule share of the global car stock. However, in recent years the UK has experienced a significant rise in the popularity of electric cars. This may be partly a result of a greater level of choice for drivers, tax incentives and more manufacturers adding longer range electric models to their product ranges.
EVs are sold on their environmental benefits of running pollution-free – supposedly without emitting the harmful greenhouse gases that contribute to climate change. However, Lukas challenges their claim to be environmental saviours because of the energy needed to manufacture such vehicles, their excessive weight and the sometimes less than green sources of energy needed to power them.
Whilst renewable generation uptake has begun, the UK remains heavily reliant on fossil fuel imports to run the power stations delivering most of its electricity. Lukas explains that EVs require more energy to produce than existing cars such as the humble Ford Fiesta. More energy currently equals more burning of fossil fuels and therefore more greenhouse gases emitted to the atmosphere at the outset. To reduce this problem, car giant BMW has taken the steps in using renewable energy to power their i series factories, but this cannot be said for the majority of manufacturers.
Another drawback of today's EVs is their heavy battery packs. A Tesla Model S weighs well over 2 tonnes. Lukas says that the heavier the car the more energy is needed to get the vehicle moving. Even with the most advanced motors, EVs will continue to experience this challenge until lighter (more energy dense) batteries have been developed. In the meantime innovative use of carbon fibre and aluminium in vehicle body-shell design can offset some of the battery weight.
Size remains as important as weight from an efficiency point of view. The larger the car the more air it has to force out of the way. In slow city traffic drag is less of a factor but EV range is greatly reduced by drag when travelling at over 40 mph. On the other hand the larger the car the less space on congested streets. The lower the traffic flow rate the more pollution from conventional vehicles.
Lukas still contends that EVs may hold great importance in the future, particularly “in busy stop-start city traffic they can make a lot of sense”.
We're now seeing the potential of lithium based batteries for domestic renewable energy storage and the possibility of connecting your lithium battery EV to your self-generating eco home. It’s possible to imagine how a smarter grid could ‘park’ energy from wind, sun and wave for the time when it’s needed if a web of EV batteries were always sitting ready to take up the charge. Alternatively excess renewable energy could be used to make hydrogen which could then run a fuel cell EV or cater for overnight domestic electricity demands.
Now we’re really getting somewhere! With increased storage capacity, the case against renewables – that they are too intermittent – starts to fall apart.
If you want to go green why not start at home? Take a free tour of Lukas’ inspirational home in Nottingham on Sat 24 Sep 2016. A home viewing with a guided tour will allow you to quiz him and get frank feedback on what worked and anything that didn’t. Register your place in advance at www.superhomes.org.uk/192
Written by Matt Malcolm and Kaoutar Nahli
Need help with any Jargon?
If you have a question about anything in the above blog, please ask it in the comments section below.
5 comments - read them below or add one