Panjaitan, Togar Wiliater Soaloon. 2005. “ASSESMENT OF RENEWABLE ENERGY TECHNOLOGIES (SOLAR THERMAL AND WINDMILS)”. Jurnal Teknik Industri: Jurnal Keilmuan Dan Aplikasi Teknik Industri 7 (1):31-40. https://doi.org/10.9744/jti.7.1.31-40.