This study, conducted with a large-scale randomized controlled trial involving 26,873 participants in the Netherlands, demonstrates that message framing significantly enhances customers' commitment to adopting solar panels. Four distinct messages were designed, emphasizing outcomes for oneself or the environment, and either cost savings or earnings. The framing that highlighted financial savings for oneself proved the most effective, resulting in a 40% higher commitment compared to the baseline and outperforming the other messages in promoting large-scale investments in green technologies.