Electric car revolution would be fuelled by 'nudging' drivers to smart tariffs, UCL research finds

Electric vehicle owners can be successfully ‘nudged’ into choosing smarter, lower-carbon tariffs for charging their cars via simple email campaigns, new UCL research published in Nature Energy suggests.

Currently, most electric vehicles are charged by their owners at peak times – usually when they get home from work – when carbon-intensive sources like coal and gas are called upon to meet the high demand. For electric vehicles to live up to their green credentials, owners must charge them at off-peak hours – when less carbon-intensive energy sources are used to produce electricity.

But the research, led by the UCL Energy Institute’s Moira Nicolson, discovers that a simple, low-cost email to new vehicle owners is an effective way of encouraging owners to adopt off-peak tariffs.

Sales of electric vehicles have dramatically increased in the last four years – from 3,500 in 2013 to 100,000 by March 2017. But to meet carbon emission targets, it is vital to ensure that vehicles are charged at off-peak hours.

The study involved sending emails to 6,000 electric vehicle owners who received the UK Government's electric vehicle grant, encompassing roughly 10% of all electric vehicle owners in the UK.

The results show that nudging owners via email was significantly more effective shortly after they purchased their vehicles. Engagement was much lower after three months of ownership, suggesting government and industry must act swiftly in order to ensure owners adopt off-peak tariffs.

The results also showed that the way in which the information is framed to electric vehicle owners also makes a big difference. Email open rates were 15% higher and click-through rates to the tariff information 90% higher when the savings associated with switching tariff were expressed as a way of cutting the cost of charging their vehicles from home rather than cutting the cost of their energy bills.

These results have direct implications for national tariff switching campaigns. In the UK, tariff switching campaigns target the average energy bill payer and are launched in Autumn to coincide with the start of the heating season when energy bills tend to increase. This study suggests that we should not rely on these generic broadcast campaigns when it comes to ensuring electric vehicle owners transition onto off-peak tariffs. Rather the results show that it would be much more effective to use an electric vehicle specific campaign timed to coincide with the date that specific individual purchased their electric vehicle, with emails providing a cheap and effective method of delivering this message in the right way and at the right time. 

Moira Nicolson, lead author and PhD candidate at the UCL Energy Institute, said:

For electric cars to meet their green credentials it is vital that they are charged with less carbon-intensive energy sources. However this relies on electric vehicle owners adopting off-peak tariffs and avoiding charging their cars at peak times.

Most of the behavioural science research in the energy domain has been confined to testing whether people are more likely to reduce their home energy use when they see their own energy use compared to that of their (usually lower consuming) neighbours'. This type of 'social norms' messaging works really well if the behaviour you're trying to encourage is the social norm - but it doesn't work very well if the 'green' behaviour is the exception rather than the rule, which is so often the case in the energy area. 

My research found that a simple email to owners within the first three months of purchasing an electric car is effective in nudging owners to off-peak tariffs, particularly if the message frames the savings from switching tariff in terms reducing home electric vehicle charging costs rather than reducing the household energy bills. “For electric cars to meet their green credentials it is vital that they are charged with less carbon-intensive energy sources. The government and industry should take these findings as a basis for a low-cost, direct and effective way of ensuring the potential of electric vehicles is harnessed.”

Notes to editors:

1. View ‘Tailored emails prompt electric vehicle owners to engage with tariff switching information’, published in Nature Energy this month.
2. For media enquiries, please contact a.blackburn@ucl.ac.uk or 0203 108 9860.
3. For general research enquiries, please contact m.nicolson.11@ucl.ac.uk