By 2030 Austria aims to meet 100 % of its electricity demand from domestic renewable sources, predominantly from wind and solar energy. While wind power reduces CO 2emissions, it is also connected to negative impacts at the local level, such as interference with landscape aesthetics. Yet, wind power comes at lower system integration cost than solar power, so that it e ectively re- duces system cost. We quantify the opportunity cost of replacing wind turbines with solar power, using the power system model medea . Our ﬁndings suggest that these cost of undisturbed land- scapes are considerable, particularly when PV is not entirely rolled out as utility-scale, open-space installations. The opportunity cost is likely high enough to allow for signiﬁcant compensation of the ones a ected by local wind turbine externalities. Keywords: externalities, wind power, system design, policy JEL: L98, Q42, C61 Corresponding author Email addresses: sebastian.wehrle@boku.ac.at (Sebastian Wehrle), johannes.schmidt@boku.ac.at (Johannes Schmidt), christian.mikovits@boku.ac.at (Christian Mikovits) 1. Introduction "Holding the increase in the global average temperature [. . . ] well below 2C above pre- industrial levels and pursuing e orts to limit the temperature increase to 1 :5C above pre-industrial levels" [52] requires rapid and substantial reductions in greenhouse gas emissions worldwide [37]. Increasing the share of electricity generated from renewable sources consequently is amongst the United Nations’s sustainable development goals (indicator 7. 2. 1) and a prominent goal of many climate and energy strategies. The European Union, for example, aims to meet at least 32 :5 % of its ﬁnal energy consumption from renewable sources [17]. Against this background, Austria aims to generate 100 % of its electricity consumption from domestic renewable sources on an- nual balance by 20301. According to government estimates, additional electricity generation of 27 TW h from renewable sources is required to meet policy goals. Out of this total increase in renewable electricity generation, 1 TW h is thought to be sourced from biomass, and 5 TW h from new hydropower generation, according to the government’s climate and energy strategy [18]. The comparatively small projected increase in electricity generation from these sources results from the perception of biomass being ecologically [15] and economically unsustainable, while further development of Austria’s hydropower potentials was considered ‘challenging’ [56] even before the projected increase in hydro generation by 5 TW h was factored in. As Austrians banned the use of nuclear power in a referendum in 1978 [42], wind and solar power are the only remaining options for a large-scale expansion of low-carbon power generation in the country. While wind power mitigates negative external e ects at the global (CO 2emissions) and the regional (air pollutants from fossil thermal power generation) level, it also imposes negative exter- nal e ects at the local level. Wind turbines are found to negatively impact wildlife [36, 54, 58], to emit noise [57], and to interfere negatively with landscape aesthetics [29, 39]. The latter is found to be the dominant negative external e ect of wind turbines [38]. Accordingly, several strands of literature seek to quantify the negative impact of wind turbines, for example through their impact on property prices within a revealed p