Energy generation in Brazilian isolated systems: Challenges and proposals for increasing the share of renewables based on a multicriteria analysis.

Concentrated in the northern region of Brazil, the country's 250 isolated systems represent around 1% of the national energy consumption and have been historically supplied by diesel power plants, an expensive solution that relies on complicated logistics and is responsible for high GHG emissions. Although many publications indicate that renewables are already a cost-effective solution, especially for economies dependent on expensive fuels, the conventional generation is still the main source of electricity on isolated systems, even in recent projects. This paper presents suggestions of public policies to stimulate the use of environmentally friendly energy sources at off-grid places in Brazil and discusses the probable reasons why this transition has not been driven yet, including barriers related to subsidies, energy tariffs and tax rules. To evaluate these policies, a multicriteria decision model was developed using the AHP (Analytical Hierarchy Process) and TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) methods, combined with fuzzy logic. Eighteen criteria were assessed, and ten specialists were interviewed. The study concluded that pilot projects of hybrid power plants, combining diesel engines and renewable technologies, would be the most effective policy. Other relevant policies pointed as relevant were the simplification of environmental licensing for projects based on renewables and the adoption of a more mandatory energy planning. • Diesel is the main source for electricity generation in Brazilian isolated systems. • Many studies suggest that renewables are already cost effective in these systems. • Six public policies are proposed to promote renewables in isolated systems. • An MCDM model (AHP-fuzzy-TOPSIS) is developed to evaluate the policies. • The policies are ranked according to their contribution to the target. [ABSTRACT FROM AUTHOR]