Energy literacy is a key factor in ensuring the protection of the natural environment. Numerous studies on energy literacy have demonstrated the development of instructional methods to promote the willingness to save energy as a critical research subject. Through a project-based activity, this research explored how hands on activities improve the energy literacy of students. A quasi-experimental design was adopted, namely a pre-test and posttest nonequivalent control group design. In total, 77 senior high school students participated in a 6-week teaching experiment. A single-factor analysis of covariance (ANCOVA) and multiple regression analyses were employed to analyze the collected data. The main findings were as follows: (1) Project-based hands-on activities helped improve the energy literacy of senior high school students; however, the effect was not statistically significant in both experimental and control groups. (2) The key factor influencing the energy conservation behavior of senior high school students was energy-related attitudes following the project-based learning process.