To strengthen energy conservation knowledge and behaviors in youth, the PowerSave Schools Program (PSP) instructs students using hands-on projects. However, there is a lack of empirical support for the PSP. The present study is the first to use a repeated measures design to assess its effectiveness in two school districts. In District 1, there was significant improvement in energy conservation knowledge and specific behaviors; however, there was no significant improvement in District 2. Reasons for this variability are discussed, emphasizing weaknesses in the current implementation of the PSP curriculum. The article concludes by discussing suggestions for improving efficacy of the PSP.