Integrated lighting systems in building at 15° S latitude: Use of photovoltaic generation as a complement

Abstract

The objective of this article is to evaluate building energy and illumination performance considering situations of total sun protection and exposure of building openings. The specific objectives were: to estimate equal illuminance curves with measurements and computer simulations; to estimate the energy savings provided by a supplementary lighting system controlled by the user (Scenario 1 - real) and another system that ignores the contribution of natural lighting (Scenario 2 - simulated); to quantify photovoltaic panel areas to meet these artificial lighting scenarios (1 and 2) and to estimate the CO2 emissions avoided by the use of natural light. It was demonstrated that Scenario 1 presented average Contribution of Natural Lighting (CIN) values of 2% and saved 10.5% of total annual energy when compared to Scenario 2. The last CIN presented was up to 17 times higher than Scenario 1, which provided excessive illumination in the room studied. It would be necessary to cover 3% and 37% of the roof with photovoltaic panels to supply energy for Scenarios 1 and 2, respectively. The installation of a photovoltaic panel system would be economically unviable, with a payback period of 60 years, longer than its lifetime. However, it was possible to demonstrate its environmental benefits, the elimination of 689kg of CO2 emissions/year, which is equivalent to the neutralization provided by four arboreal units in the same period.