Appeals to act pro-socially are becoming an increasingly popular way for utilities and authorities to encourage environmental-friendly behavior because of lower financial costs than if price incentives were used. However, recent research suggests that these measures might be emotionally taxing for utility consumers. In this article, we present the results from a randomized field experiment conducted on a sample of 1967 customers serviced by a Danish electricity company. Our results support the suggestion that socially motivated appeals are significantly more emotionally taxing than monetary incentives. We find that this difference disappears when the pro-social appeal is supplemented with a monetary incentive. Finally, we suggest a strategy for reducing emotional ‘costs’ of pro-social appeals without increasing financial costs or reducing the effectiveness of the appeal.