Firms buy renewable energy at premiums and report environmental concerns as motivation to do so. The bulk of the literature on environmental corporate social responsibility suggests that this type of behavior even results in higher profit. However, a product-differentiation framework with perfect competition predicts that renewable energy use has no effect on profit. This paper tests this prediction by investigating the relationship between firms' renewable energy use and profit on the basis of panel data for 920 firms over 2014–2018. We do not find evidence for an impact of renewable energy use on profit. Hence, a ‘win-win’ in the form of higher profit and a better environment does not seem to exist. In addition, the results appear to suggest that firms do not have a positive willingness to pay for renewable energy as contribution to the environment. This implies that firms are only willing to contribute to climate-change mitigation through buying renewable energy when this is aligned with the profit-maximization objective.