Renewable and non-renewable exergy cost and specific CO2 emission of electricity generation: The Brazilian case

The average unit exergy cost and CO2 emissions of the electricity generated in Brazil are evaluated using the national electricity mix and considering the representative profiles of the electricity generation routes. The Brazilian installed capacity is composed of hydropower plants, natural gas, fuel oil and coal fired thermoelectric plants, biomass cogeneration plants, nuclear plants and wind farms. By using exergoeconomy to distribute exergy costs and CO2 emissions in multiproduct processes and by weighting the CO2 emissions and the renewable and non-renewable exergy consumption of each type of plant, it is possible to obtain the average unit exergy costs and specific CO2 emission for the whole electricity generated. An iterative calculation procedure is used to take into account cyclic interactions of the processed fuels and electricity generated. The renewable and non-renewable exergy costs together with the CO2 emissions provide a reasonable way to compare the electricity and its final applications with other energy sources.