Mapping the potential for a combined generation of electricity and industrial process heat in the northeast of Brazil - Case study: Bahia

Abstract

Industrial Process Heat represents a large part of the energy demands of industries. A parabolic trough solar plant with cogeneration can meet the thermal and electric demand of these industries, mainly at medium and low temperatures.In this work, a linear parabolic solar plant for generation of electricity (1 MWe) and industrial process heat (1 MWt) were simulated at a small industry situated in the State of Bahia. The levelized costs of heat (LCOH) for an evacuated tube solar plant resulted, for extensive regions west and north (Carinhanha (IGR 10, Guanambi), Barra (IGR 4, Feira de Santana), Bom Jesus da Lapa (IGR 10, Guanambi), Santa Rita de Cássia (IGR 8, Barreiras), Paulo Afonso (IGR 3, Paulo Afonso), Remanso (IGR 6, Juazeiro) and Correntina (IGR 8, Barreiras) of the State of Bahia, in the range of 2.85–2.97 ¢/kWh-t. When compared to the medium LCOH produced by the combustion of natural gas in the United States (2.8 ¢/kWh-t) and in European Union (between 3.5 and 5.9 ¢/kWh-t), have shown to be quite competitive. Even in the case of using non-evacuated tubes collectors, the region mentioned has a LCOH in the range of 3.93 ¢/kWh-t to 4.19 ¢US$/kWh-t and still competes with costs in Europe.The levelized costs of electricity (LCOE), considering a linear parabolic solar power plant with evacuated tube collectors and ORC cycle, resulted in minimum and maximum values of 0.225 US$/kWh-e and 0.591 US$/kWh-e for the State of Bahia. In 2019, commercial enterprises of CSP technology reached LCOE values in the range of 0.10 US$/kWh-e to 0.243 US$/kWh-e and, therefore, the LCOE for the most promising regions of Bahia (west and north) have shown to be competitive in the current market. The study also showed that is indifferent to the use of Organic Rankine Cycle (ORC) or Vapour Rankine Cycle (VRC) for the generation of solar energy in the promising regions identified in the State of Bahia. The explanation is that, although the ORC is more efficient than the VRC for operational temperatures of this power plant, its cost is still very high, both for still being under development and for its small scale of production. As consequence, the recommendation of this study is the use of VRC turbines, which are already manufactured in the country and are routinely used to convert biomass to electricity.