The characterised results suggest that the operation of the CSP plant in solar-only mode produced the lowest environmental impact in almost every category. This was especially relevant in regards to climate change (26.9 kg CO2 eq), terrestrial acidification (168 g SO2 eq) and photochemical oxidant formation (160 g NMVOC) categories. Utilization of different auxiliary fuels had a determinant effect on the environmental performance of the plant. The coal scenario produced the highest scores in every category except for natural land transformation (whose highest score was found in the fuel oil scenario).
Fig. 1 shows the normalised profile for each case scenario. The represented values show the differences between the normalised results for each case and the corresponding solar-only value. The negative values for a natural gas scenario (in freshwater eutrophication and toxicity) indicate a better performance for that scenario than in a solar-only operation, due to the increase of electricity generation and the low impact of this life cycle fuel on those categories (as indicated in Corona et al. [22]).