State Senior High School (SMAN) 96 is the first high school in Jakarta to be officially designated as a net-zero school with a Greenship Certificate by the Green Building Council Indonesia. In contrast, State Vocational High School (SMKN) 73 is not a net-zero school. The two schools are 100 m apart, located in Cengkareng District, West Jakarta. The purpose of this study is to analyze the application of CO2 emission reduction technology in the two schools. This study used a quantitative method. Because the school setting is in the urban area, it is not easy to find so-called indigenous technology. This study will look at the best available low carbon technologies implemented in both schools. The results show that SMAN 96 has electricity consumption and CO2 emissions lower than SMKN 73 because SMAN 96 already using the energy-efficient devices/appliances and minimizing the usage of AC and refrigerator which can increase the CO2 emissions. To reducing CO2 emissions, the two schools already implementing the use of solar panels. Furthermore, by using the solar panels it can save the electricity consumption and also solar panels produces emissions smaller than total electricity usage.