Photovoltaics (PVs) provide clean and affordable energy contributing to the decarbonisation of the energy sector. High surface temperature of the PV modules reduces their efficiency and the corresponding energy production and increases the sensible heat released to the atmosphere contributing to urban overheating. For roof mounted PVs, increase of the roof albedo helps to decrease the surrounding ambient temperature, raises the efficiency of the PVs and increases the reflected solar radiation received by the modules. Numerous studies have assessed the impact of increased roof albedo on the energy yield of the monofacial and bifacial PVs for given installation characteristics and specific climatic conditions. There is a serious need to collect, analyse, compare, and parameterize the existing information in order to provide more global and holistic knowledge to the PVs industry. We have analysed 13 and 57 case studies reporting the impact of modified roof albedo on the energy yield of monofacial and bifacial PV modules, respectively. It is concluded that, on average, increasing the roof albedo by 0.1 contributes to enhance the energy production of monofacial and bifacial PV modules by 0.7% and 4.55% respectively while delivering important co-benefits to urban heat mitigation. Parametric relations between the potential increase of the roof albedo and the increase of the annual energy yield are proposed for both monofacial and bifacial PV modules. The impact of the geographic and installation parameters on the energy production of the modules is analysed and discussed. The results of such a study could help to identify the optimal roof albedo for maximizing energy performance and reducing energy costs.

A. Synnefa (School of Built Environment, Faculty of Arts, Design and Architecture, University of New South Wales), M. Santamouris (School of Built Environment, Faculty of Arts, Design and Architecture, University of New South Wales)

K. Vasilakopoulou, G. Ulpiani, A. Khan, A. Synnefa, M. Santamouris,
Cool roofs boost the energy production of photovoltaics: Investigating the impact of roof albedo on the energy performance of monofacial and bifacial photovoltaic modules, Solar Energy, Volume 265, 2023,
111948, ISSN 0038-092X, https://doi.org/10.1016/j.solener.2023.111948.