Generally, producing used oil from households to be bio-diesel fuel is a way to conserve the energy because used oil that seems to be useless can generate enormous values and benefits like what we call bio-diesel fuel production.
In spite of bringing used oil from households to produce bio-diesel, it is not satisfying because the electrical power is still needed. Hence, this is taken to be an idea and becomes a successful research afterwards. That is the production of bio-diesel by solar energy invented by Assoc. Prof. Anoot Jumlongkoon from the Faculty of Engineering of Rajamangala University of Technology Thanyaburi (RMUTT).