Water and energy consumption in schools: case studies in Brazil

Over the past decade, rising water and energy consumption in educational institutions has become a topic of increasing attention among the scientific and policy communities. This work assesses the potential for water and energy savings in 100 public schools in southern Brazil. There was great variation in the water consumption (0.81-35.43 l/student/day) and also great variation in the energy consumption (0.31-66.47 kWh/student/month). Two schools were selected for assessing the implementation of a rainwater harvesting system and improvements in the artificial lighting system. One of the schools has high water and energy consumption, while the other has low consumption. In the school with high consumption, the potential for potable water savings by using rainwater varied from 2996 to 5431 l/day; and the payback period ranged from 20 to 36 months. The potential for energy savings by improving the artificial lighting system was 62%; and the payback period was just five months. In the school with low consumption, the potential for potable water savings by using rainwater ranged from 542 to 1574 l/day; and the payback period ranged from 46 to 83 months. As for the improvements in the artificial lighting system, there was an increase of 13% in the monthly energy consumption due to the current low illuminance levels in the classrooms. The results show the importance of choosing strategies for decreasing water and energy consumption in schools. Such strategies are usually economically and environmentally feasible, bringing significant reduction to the consumption of water and energy.