Studied and affirmed again, this time by MIT: 90% of commute trips short enough for an economy EV and at-home charging

Gas and charging station free living, and the end of ‘range anxiety’

17 Aug 2016, excerpt adapted from Business Green 

New research published this week by a group of scientists at the Massachusetts Institute of Technology (MIT) found 87 per cent of ‘vehicle days’ in the US could be completed with a modestly priced electric car on the market today, using a single battery charge.

The results suggest that even if an EV owner did not come across a charging point all day, they still would have enough battery to complete their day’s journeys and return home to charge at a domestic plug point in almost nine out of 10 use cases. The figure holds across a diverse range of US cities, even when per capita consumption of petrol or diesel varies significantly.

The MIT group estimate that if 90 per cent of US personal vehicles were in fact replaced with EV alternatives, the carbon reduction impact would be impressive – a 30 per cent cut in emissions from transportation, which could rise significantly if power plants decarbonised to increase the proportion of vehicles running on low-carbon electricity.

And crucially, the researchers found that at today’s prices, switching from internal combustion engines to EVs would be cost-neutral for drivers.

The four-year project involved the integration of two huge datasets mapping millions of driver miles across the US: one a detailed log of second-by-second driving behaviour based on GPS data gathered across four US states, the other a national data set based on travel surveys. The resulting analysis takes into account not only the distance driven, but also the ambient temperature, time spent idling, intensity of acceleration and other factors, all of which affect the performance of an EV battery.  Holidays, long-distance road trips, and days when a lot of energy is needed to heat or cool a car’s interior, are cited as examples of when an EV may not be able to meet the needs of the day on a single charge.

At home charging is still an issue for many households, though some cities are dealing with this by requiring it in new construction.  According to an August 2016 report from the International Renewable Energy Agency (IRENA), only 56 per cent of vehicles in the US have access to a dedicated off-street parking space, and many of these are not near a power outlet.

There is a similar issue in the UK, where in urban areas houses or flats with dedicated off-street parking are scarce. Therefore more investment is needed to roll out on-street parking along residential roads – a point made by Richard Turnbull, head of infrastructure at London black cab maker LTC, in response to the report. “Building on street, rapid charging will still be essential in tackling urban air quality issues and low carbon transport targets,” he noted in a statement.

But Jessica Trancik, the study’s lead author, believes the research is a significant step towards convincing people that for the vast majority of car owners, EVs will be able to slot seamlessly into their existing lifestyles. “Developing the concepts and mathematical models required for a testable, quantitative analysis is helpful in these situations, where so much is at stake,” she said in a statement.

And importantly, the analysis is based on the range and performance of relatively low-cost EVs on the market today, such as the Ford Focus Electric or the 2013 Nissan Leaf, which have a range of between 70 and 90 miles. If average driver journeys are compared to premium EVs such as Teslas, which have a driving range of around 300 miles, the 87 per cent figure would edge much closer towards 100 per cent.

The MIT study may have delivered the data, but it won’t yet have convinced everyone. But as charging networks grow, and battery performance continues to improve, EVs will be able to replace a larger proportion of car days – and provide drivers with a more robust ‘safety blanket’ of nearby charge points and excess charge facilities. Add in effective car rental services for days when longer trips are unavoidable and the case for EVs looks more compelling than ever.

Range anxiety may not yet have disappeared completely, but it is firmly in the rearview mirror.