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.