The carbon intensity of integrated photovoltaics

To assess the meaningfulness of installing solar photovoltaics (PVs) in buildings and infrastructures, we consider a carbon intensity (CI) balance perspective and assess whether installing PV at different orientations acts as a net CO2 sink or source when compared with the same amount of carbon that would be emitted using the local electricity mix. The mean values obtained for the CI of PV in buildings in Europe correspond to 36 gCO2-eq/kWh for an optimally oriented rooftop PV installation. For facades, this corresponds to 51.4, 71, and 214 gCO2-eq/kWh, respectively, for S-, W-/E-, and N-facing facades. Notably, the potential to halve these figures by 2030 already exists. These figures are compared with CI mean values for national electricity mixes: 374.5 gCO2-eq/kWh. For most countries, the integration of PV in facades (often including N-facing PV facades) would not penalize—and conversely support—a transition toward a carbon-neutral electricity mix.