Comparative analysis of solar power technologies through Life Cycle Assessment approach

Through the Life Cycle Assessment (LCA) approach, a comparative environmental analysis was carried out to evaluate both photovoltaic (PV) and concentrated solar power (CSP) technologies. The analysis was performed on the basis of the same key parameters (location, solar radiation, etc.), considering three different power plants: a PV plant with polycrystalline Silicon modules, a Parabolic Through CSP plant (PT-CSP) and a Central Tower CSP plant (CT-CSP). All the plants are equipped with solar tracking systems. Manufacturing processes of materials and components of the power plants, their transportation, the operation and the end of life of the power plants themselves are considered, while construction activities, maintenance and dismantling activities are omitted. The functional unit chosen is 1 kWh of electricity produced by the plant and the following key indicators were calculated to make the comparison: Greenhouse Gases (GHG) emissions over a 100 years time horizon and Energy Payback Time (EPT). The analysis shows an overall impact of the PV plant significantly higher than both CSP plants: GHG emissions for PV plant are equal to 34.4 gCO2eq/kWh, while for PT-CSP and CT-CSP the values are, respectively, 20.6 gCO2eq/kWh and 14.2 gCO2eq/kWh. The trend in results is the same for EPT, in fact it results 2.1 years for PV, 1.2 years for PT-CSP and 0.7 for CT-CSP. The results are also in agreement with the data reported in literature.