In 2016, after a typhoon hit the city, dozens of power poles were damaged and caused a blackout that lasted hours, she explained.
The blackout had led to congestion on some of the main roads, while several public services were paralyzed, Rismaharini added.
The city government planned to add more solar-powered traffic lights in Surabaya, the capital city of East Java Province, Rismaharini noted.
The cost of maintaining solar-powered traffic lights was less than the regular ones, the mayor stated.
It cost only Rp90 thousand for a monthly maintenance check of solar-powered traffic lights, as against Rp1 million per month for the regular traffic lights powered by the State electricity firm's cable network, she further explained.
Besides traffic lights, the Surabaya City government also used solar cells to power streetlights, water pumps at state schools, bus terminals, public offices, and public water pumps.