Brazil (UFF) Renewable energy generation for isolated territories of the country

Located 1,200 kilometers off the coast of the city of Vitória, capital of Espírito Santo, Trindade Island is part of a small archipelago located in the Atlantic Ocean formed by two main islands: Trindade and Martim Vaz. The territory corresponds to an important strategic point for national defense, in addition to being the cradle for several species of Brazilian fauna and flora, some only found in the region.

The island is the focus of the article “Feasibility of integrating renewable energy in isolated systems in Brazil – A case study on Trindade Island (Espírito Santo, Brazil)”, published in February this year. The result of the master’s thesis in Biosystems Engineering by student Andrey Dias, from the Fluminense Federal University (UFF), in collaboration with the Brazilian Navy, the work explores the possibility of using renewable energy matrices for isolated locations in the country.

“We can think about the adoption of renewable alternatives under several aspects, such as reducing the cost of buying and transporting diesel, as renewable energy uses local resources; the reduction of local and national impacts, since we would not have the burning of fuel or the consumption of fuel itself to take this material from the mainland to the island and the increase in the self-sufficiency of the territory, because, with renewable sources, in the event of a failure in the supply of diesel, the base would still have electricity to continue its activities”, explains the professor of the Department of Agricultural and Environmental Engineering at UFF, Marcos Alexandre Teixeira, one of the authors of the study and co-supervisor of the dissertation.

The study focuses on how to have an electricity supply totally based on renewable sources (hydroelectricity, wind and solar generation) for activities on Trindade Island. “We seek to answer if it is possible, with what technologies, if we have equipment for this available in the Brazilian market, what data and information we need and where to find them to be able to make this dimensioning”, exemplifies the researcher.

Isolated systems

Isolated systems are places that do not have poles to take electricity from the generating units to homes. This is the case of Trindade Island, an important military and meteorological base region that produces data to understand the climate and predict extreme events, as well as a fundamental territory for marine biology studies.

Aerial view of the Oceanographic Post of Trindade Island, located in the state of Espírito Santo / Photo: Marine News Agency (Disclosure)
#ParaTodosVerem The image shows an aerial view of the Oceanographic Post of Trindade Island, surrounded by trees and spaced buildings

For isolated territories such as Trindade Island, the first challenge is transport logistics, as everything that goes to the site and from there returns to the mainland must be transported by Navy ships and unloaded via boat, since the island does not have a port for mooring. Thus, the solution involves the maintenance of a set of diesel generators, which requires the shipment of fuel and parts from the mainland.

Wind energy is more efficient

During the study, four energy generation options were evaluated: wind associated with diesel; solar with batteries; wind power with a water storage system; and photovoltaic (a system that converts solar energy into electricity) associated with diesel. In view of the cost-benefit criteria, the research considered wind generation associated with diesel as the best option to meet the island’s electricity demands. According to the professor, several factors were considered to analyze the alternatives, mainly the difficulty and costs of installation, the possibility of meeting all the demand of the island and the impacts on the biodiversity of the territory.

Table with the costs for implementing renewable energy systems. Respectively: wind associated with diesel, solar with batteries and wind with water storage. Source: article “Feasibility of integrating renewable energy in isolated systems in Brazil – A case study on Trindade Island (Espírito Santo, Brazil)”

“Based on these parameters, the implementation of wind energy in parallel with the generation of existing diesel presents the possibility of being progressive, with one wind turbine at a time, facilitating the installation operations of wind turbines in this remote location. This model allows us to safely assess whether the wind and generation predicted for the wind turbine are correct, ensuring a better adjustment as the project evolves”, highlights Teixeira.

The study indicates small and medium-sized wind turbines – initially of 10 kilowatts (kW) – that would be installed on the land part of the island. Another preponderant factor for the adoption of the wind model is the generation of energy also at night and for longer throughout the day, which reduces battery costs. As a safety factor for such an isolated location, the research indicates the maintenance of diesel generators as a subsidiary source of energy in cases of emergency.

10 kW wind turbine model equivalent to those indicated in the study. / Credit: Windup.pt

In addition to highlighting the feasibility of a renewable energy system, the research brings a methodology that can be reproduced in other isolated spaces. “This method used to assess the potential can be replicated to other places, as data sources available for anyone to be able to reproduce it in any other location in the national territory were used. Once learned, the Navy itself, with its engineering corps, can reproduce this type of study in other locations,” Teixeira concludes.

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Marcos Alexandre Teixeira is a professor in the Department of Agricultural and Environmental Engineering at the Fluminense Federal University (UFF). He holds a bachelor’s and master’s degree in Agricultural Engineering and a PhD in Mechanical Engineering from the State University of Campinas (UNICAMP), with experience in the development of EPC Turnkey Projects, developed during his work in industrial project companies in Brazil. During her postdoctoral studies, from 2004 to 2008, she worked on international cooperation and research projects in the areas of renewable energy systems, poverty alleviation and CDM projects in countries in Africa, Europe, Brazil and China and Indonesia.