Contents lists available at ScienceDirectSolar Energyjournal homepage: www.elsevier.com/locate/solenerEstimating the environmental footprint of a grid-connected 20 MWpphotovoltaic systemArtúr Szilágyi ? , Gyula GrófDepartment of Energy Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, 3-5 M?egyetem rkp., Budapest 1111, HungaryA R T I C L E I N F OKeywords:Life cycle assessmentPhotovoltaicsEnvironmental footprintA B S T R A C TBalance-of-system components represent a growing share of environmental impacts in photovoltaic utility-scalesolar energy systems. There are, however, no ef f ective methods to carry out screening type life-cycle assessmentduring the planning phase of the power plant to minimize these impacts. This paper uses the EuropeanCommission’s novel product environmental footprint methodology to explore the life-cycle impacts of a casestudy in Hungary and applies two life-cycle models with dif f erent system boundaries and assumptions. The f i rstmodel represents a full-f l edged assessment with a detailed inventory, while the other, simplif i ed model can bedirectly linked to the main plant design parameters. Our results show that: a) the production of photovoltaicmodules account for around half of the total aggregated environmental impacts, b) compared to the Hungariangrid mix, the new power plant reduces the environmental footprint by 75%. It is also shown that the simplif i edmodel captures the overwhelming majority of impacts, thus, it is applicable during the eco-design of similarsystems.1. IntroductionFighting climate change and air pollution requires alternatives toconventional fossil-based energy generation options. This need forcleaner energy technologies created a market for photovoltaic (PV)power, which has seen spectacular growth and continuous improve-ment in manufacturing and cell ef f i ciency in the last two decades. This,coupled with a ten-year decrease of 75% in prices, led to a quicklyexpanding PV stock, almost doubling in every four years and well ex-ceeding 500GW total installed capacity in 2018 (Jäger-Waldau, 2019).The market is expected to follow this trend in the next decade withestimates ranging from a “mere” doubling to a more than tenfold in-crease in installed capacity by 2030 (Jäger-Waldau, 2019).Scientif i c interest in the environmental performance of silicon-basedPV systems started long ago (e.g. Huber and Kolb 1995). Later,Fthenakis and Kim (2007) were among the f i rst researchers to de-termine the greenhouse gas (GHG) emissions associated with themanufacturing, installation, operation and, disposal of utility-scalesolar energy (USSE) systems using life cycle assessment (LCA). Theirresults showed that PV module manufacturing was clearly the largestcontributor to climate impacts dwarf i ng other life cycle stages andequipment by far (Fthenakis and Kim, 2011, 2007). In a case study of agrid-connected 3.5 MWp capacity PV facility, they examined the LCA ofthe balance of system (BOS) in detail (Mason et al., 2006). They foundthe share of concrete production, plant construction, and the disposal ofcomponents negligible both in terms of GHG emissions and energy use.Based on their experience, they also provided guidance on the LCA ofPV systems (Fthenakis et al., 2011). Later studies conf i rmed their re-sults, e. g. Desideri et al. (2012) conducted an LCA of a 1.8 MWpground-mounted grid-connected PV plant underpinning the importanceof PV modules, support structure, electrical cables and inverters overfencing, land preparation and electric substations.Others extended the scope of their study to include wood supportstructure and sun-tracking systems, f i nding that both reduce GHGemissions when compared to metal support and no tracking (Beylotet al., 2014). The authors also called for more detailed evaluation be-cause, according to their f i ndings, environmental impacts are not in adirect linear correlation with the installed capacity.Another study looked specif i cally at large scale ground-mountedsystems considering dif f erent module types and geographical locationsfor manufacturing and installation (Leccisi et al., 2016). In line withtheir results, climate impact variations of such PV systems can be lar-gely explained by the energy mix used during the manufacturing of PVcells, the type of module (e.g. CdTe, mono- or multi-crystalline Si wafermodules) and the annual irradiation at the installation site.The environmental optimization of these systems also is becoming ahttps://doi.org/10.1016/j.solener.2020.01.028Received 26 October 2019; Received in revised form 8 January 2020; Accepted 11 January 2020? Corresponding author.E-mail address: szilagyi@energia.bme.hu (A. Szilágyi).Solar Energy 197 (2020) 491–497Available online 20 January 20200038-092X/ © 2020 International Solar Energy Society. Published by Elsevier Ltd. All rights reserved.T
