This research evaluates the effectiveness of Project ReCharge, an energy efficiency, STEM curriculum designed for middle and high school students. The project includes a five-unit curriculum, and monthly professional development spanning a year. The project was implemented in ten schools over three years. Four areas were explored in the study including (1) changes to student content knowledge, (2) changes to student attitudes towards STEM subjects and careers, (3) changes to teacher self-efficacy and beliefs, and (4) changes to teacher content knowledge. A content test for teachers and students, the STEM Semantics Survey, and STEBI-A were used to collect data on 4123 students and 47 teachers. Data were collected in a quasi-experimental design utilizing parametric and nonparametric techniques. Analyses suggest student content knowledge increased significantly from pretest to posttest for all years (Pretest: M = 11.38, SD = 4.97, Posttest: M = 16.67, SD = 5.83, t = 45.05, p < 0.001, d = 0.98). Increases to student attitudes in STEM varied by year and grade, but overall increases were found in science (N = 2362, z = -2.618, p = 0.030, eta[superscript 2] = 0.002), and math attitudes (N = 2348, z = -2.280, p = 0.023, eta[superscript 2] = 0.002). High school students tended to show more increased attitudes in more subject areas than middle school students. No changes to teacher self-efficacy and beliefs were found, and increases to teacher content knowledge only occurred in the third year (N = 22, x[superscript 2] = 5.158; p = 0.076, eta[superscript 2] = 0.319). [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]