Policies that mandate the adoption of renewable energy innovations could ensure their widespread adoption. Yet, such policies may not be implemented if they face strong opposition from the public, especially when strong negative emotions are at the core of opposition. In a field experiment (N = 97), we investigated people's emotional responses to two policy options aimed at increasing the adoption of heat pumps in a neighbourhood in the city of Groningen: a campaign promoting the voluntary adoption of heat pumps versus a regulation that mandates the adoption of heat pumps. In line with reactance theory, the policy option mandating the adoption of heat pumps was perceived to threaten people's freedom more and, in turn, caused stronger negative and weaker positive emotions than the policy option promoting voluntary adoption. Yet, emotions towards the policy options were also related to people's values, providing partial support for the Value-Innovation-Congruence model of Emotional responses. Stronger egoistic values were related with stronger negative emotions, particularly towards the policy option mandating adoption, while stronger biospheric values were related with stronger positive emotions, but only towards the policy option promoting voluntary adoption. Emotions, in turn, were related with acceptability of the policy options. Our findings imply that measures aimed at increasing positive emotions and reducing negative emotions towards policies aimed at increasing the adoption of energy innovations could profit from considering people's core values.