Evaluating the Impact of Photovoltaics for Lifecycle Global Warming Potential of Buildings According to EN 15978 - A Danish Case Study

The EU energy performance of buildings directive (EPBD) has recently been updated to tighten energy performance regulations and is demanding solar solutions on all buildings, to be fully implemented by 2030 through national building codes. However, article 7 also states that life cycle global warming potential (GWP) must be calculated (according to EN 15978) with a reference study period of 50 years, and that national limit values on life cycle GWP must be introduced by 2030. Denmark has since 2023 enforced this methodology with national adaptions and parameters. This work evaluates the impact of PV on the GWP of buildings following Danish rules, using collected environmental product declarations of PV system components. The results show, that for almost all cases the addition of a PV system increases the GWP of buildings, owing to a combination of a high GWP load of PV materials compared to standard roofing materials, decreasing emission factors (based on political ambitions of climate neutrality), and high impact of component replacement. Tying the GWP benefits of PV to political ambitions of renewable energy generation decreases the value of PV in countries with high political ambitions and does not appropriately consider buildings as an active part of the energy system. Therefore article 7 in part counteracts the stated intentions of the EPBD and the authors recommend that PV should be excluded from the GWP assessment of buildings.