This study uses a multicriteria decision model to solve a problem of energy source selection in order to identify which type of renewable energy is the most viable for Brazilian ports to invest in. This research considers wind energy, photovoltaic energy, and wave energy from a multicriteria perspective. Twenty criteria were defined in a brainstorming process that relied on sustainability management principles, information presented in the literature, national standards, national energy policy legislation, and data from previous or ongoing renewable energy projects in ports. These criteria were then evaluated by the Brazilian Energy Research Office (EPE) on a five-point Likert scale. The multicriteria approach adopted herein is based on the flexible and interactive tradeoff (FITradeoff) method. This process allows for the implementation of a linear programming model to identify potentially optimal alternatives. The assessments performed herein found photovoltaic energy to be the most viable renewable energy source for Brazilian ports to invest.