Environmental and energetic behavior of a Beam-down linear Fresnel solar field for low-grade thermal energy applications
E. Batuecas, Sebastián Taramona, Jesús Gómez-Hernández, Javier Villa Briongos
Abstract
Solar concentrators can be used to provide low-grade thermal energy in industry for improving overall efficiency and targeting the emissions reduction goals. In this context, to develop an effective Concentrated Solar Technology for utilizing low-grade thermal energy, different configurations of a beam-down Fresnel solar field are analyzed in terms of thermal energy production and environmental impacts as Global Warming Potential (GWP), Ozone Depletion Potential (ODP) and Particulate Matter (PM). Once the geometry of the solar field is defined, the yearly incoming energy at the solar receiver is obtained. Subsequently, the GWP, ODP and PM are calculated with the Life Cycle Assessment methodology for construction and operation phase. Those environmentally lighter designs in the construction phase are not those that obtain lower results when the energy they provide is analyzed. The GWP and ODP results showed that producing low grade thermal energy with all but two of those beam-down configurations obtained better results than the conventional heat from natural gas. The case study with lowest carbon footprint represents 34.2 % reduction compared to natural gas and 41 % reduction in ODP. However, PM obtained better results for conventional heat than for the proposed solar fields. Configurations with C = 24 as solar concentration ratio achieved the optimal configuration with a good balance between energy production and the analyzed environmental impacts.