Toward an integrated assessment of the performance of photovoltaic power stations for electricity generation

In this paper a photovoltaic (PV) technologies for electricity generation accounting scheme is proposed and applied. The adopted scheme aims to overcome limitations of conventional indicators such as EROI (Energy Return on Investment) and EPBT (Energy Payback Time) and to present a more comprehensive description of energy and material transformations. The proposed methodology is based on the Multi-Scale Integrated Analysis of Societal and Ecosystem Metabolism (MuSIASEM) approach. In this work, four dimensions of sustainability which should be addressed for the purpose of identifying the limiting factors of photovoltaic systems for electricity production are presented: Energy and Material Accessibility; Environmental Health Desirability; Technological Achievability; and Socioeconomic Acceptability. In relation to these four dimensions, the direct and indirect requirements of flow and fund elements (silver, energy carriers and water as flows; human time and land as funds) in photovoltaic power stations based on crystalline silicon wafer cells are evaluated and the implications of the overall performance and limitations of the present PV systems are discussed. These parameters are also compared with other electricity production technologies as well as benchmarked against the performance of the energy and mining sector of a modern country (Spain). It is concluded that the availability of silver could constrain photovoltaic cell manufacturing. Furthermore, the low power density of photovoltaic installations could drive a remarkable land rush. Finally, the human labor allocated in the fund-making process could represent a serious constraint in respect to the requirements of the metabolism of modern societies.