Unveiling Fernando de Noronha Island's photovoltaic potential with unmanned aerial survey and irradiation modeling

Abstract

The universalization of electricity still presents significant obstacles to achieving the United Nations Sustainable Development Goals. There are still many remote areas, such as oceanic islands and isolated communities disconnected from the grid, that depend on fossil fuels to make it viable. Fernando de Noronha, a tropical oceanic island in Brazil, is a typical case where replacing the diesel-based power plant for renewable energy is imperative, therefore, it served as a testbed for this investigation. This paper presents the implementation and results of a low-cost framework for assessing the photovoltaic potential of rooftops. Using a real case study, the objective is to explore how effective rooftop photovoltaic systems could be on Fernando de Noronha Island by applying low-cost aerophotogrammetry, geospatial analysis and scenario creation. The first approach was mapping buildings, open spaces and solar obstacles using unmanned aerial photogrammetric survey that delivered high-quality digital elevation surface. The 3D rooftop surfaces fed the solar irradiation models and enabled to compute the photovoltaic potential of suitable rooftops. Findings show that 83.3% of the total building rooftop area was deemed economically viable for photovoltaic installations. Furthermore, 80.0% and 60.0% of the rooftops receive annual irradiation levels >1600 kWh/m2 and 2000 kWh/m2, respectively, indicating high potential for exploiting solar resources on decentralized, highly irradiated rooftops. The scenario with the highest photovoltaic potential is three times higher than the lowest. The results indicate that the suitability of rooftops for various photovoltaic system sizes offers the possibility of deploying a combination of smaller and larger urban photovoltaic installations. Furthermore, the decentralized photovoltaic rooftops can compensate for between 66 and 199% of the estimated annual consumption of 31 GWh in 2031. The method is highly transferrable and limited solely by the availability of sources of geospatial data and coordination with stakeholders. The investigation meets the needs of the Brazilian Ministry of Mines and Energy, therefore meeting the environmental needs of the energy sector by promoting renewable energy for the island which is a UNESCO Natural World Heritage Site and Brazilian National Marine Park and Environmental Protected Area. The investigation demonstrated that creating photovoltaic potential scenarios that nurture informed decision-making processes is a crucial initial step in urban renewable energy planning. The pioneering 2000-ha unmanned aerial photogrammetric survey proved to be a cost-efficient method for producing accurate data for modeling the irradiation and photovoltaic potential in urban areas. The investigation fills the literature gap on modeling photovoltaic potential for remote islands by blending unmanned aerial vehicles and geospatial tools.