THERE is one promise that Ismail Fahmi has not fulfilled to netizens, which is to provide a calculation for the cost of installing rooftop solar panels. Ismail is the founder of Drone Emprit, a system that monitors social media conversations. He was flooded with questions from Internet users when he installed rooftop solar power generator (PLTS) at his new house in South Jakarta in November 2022. Internet users were not only curious about the cos