This paper investigates the sustainability of the Spanish electricity system under four different scenarios for 2030 and 2050 published by a reputable think tank assessing the Spanish Government. The analysis was performed using a life cycle approach and evaluates five sustainability indicators: overall carbon footprint, carbon footprint per MWh, overall economic costs, LCOE and job creation. The results evidence that the most ambitious scenarios (100 % share of renewables) produced the best results in terms of environmental and socio-economic performance (10-fold reduction of GHG emissions and 15-fold increment in employment compared to 2015) but involved higher costs (15 €/ MWh more expensive).