Estimating the global technical potential of building-integrated solar energy production using a high-resolution geospatial model

Abstract

The building sector is responsible for about one third of the global final energy consumption and CO2 emission, thus it is desired to limit and replace building-related fossil energy sources to meet climate goals. In this context, the utilization of building integrated solar technology has proven to be a reliable and increasingly affordable alternative, however, there is still an immense potential remained unexplored. This study thus uses, a highresolution, geospatial energy supply model to estimate the useable building rooftop areas across 11 regions of the World, and calculates the corresponding global and regional potential of energy production of state-of-the-art rooftop PV/T collectors over a 39-year period. Our results demonstrate that solar PV/T energy production on residential and commercial/public rooftops has enormous global potential (47.5 PWh), with the possibility of doubling by 2060. The current magnitude of potential implies that about 60% of the suitable building rooftops could be installed with PV/T collectors to offset most of the local energydemand. Regarding the future trends we found that beyond the extended building stock in large economies (e.g., China, USA and EU), the newly-built commercial buildings of developing regions (e.g., Latin America and South Asia) are modeled to have key role in realizing the estimated potential over the next decades. Our study also focuses on the geographical, temporal and building-level characteristics of energy production and concludes that rooftops in the Middle East, South and Pacific Asia have the most favorable geographical exposure for capturing solar (dominantly thermal) energy by PV/T collectors. It was found to be especially valid for months during the warm season. In regions dominated by temperate climate, the energy generation is characterized by a second maximum before the warm season, due to the peak of electricity production. At the time of the production peaks and in general annually, irrespective to regions, PV/T collectors installed on single-family roofs and retails were estimated to have the greatest potential to supply green energy for the entire building and thus likely to balance the in-situ energy consumption.