Abstract
Tall buildings use substantial energy but also offer extensive façades and elevated rooftops for on-site renewable electricity generation. Building-integrated photovoltaics (BIPV) and small urban wind turbines (SUWTs) may therefore utilise complementary solar and wind resources in dense urban environments. However, the life-cycle energy and greenhouse gas emissions (GHGe) performance of combined BIPV-SUWT systems in tall buildings has not been comprehensively evaluated through a parametric framework.
This paper develops a computational-analytical life-cycle assessment framework for BIPV-SUWT systems in tall buildings across Melbourne, Sydney, Brisbane, Adelaide and Perth. The framework integrates parametric building geometries, urban-context effects, monthly local renewable resources and regional electricity mixes with a hybrid life-cycle assessment approach over 25 years. Overall, 97200 scenarios are evaluated.
Key findings highlight that: (1) BIPV contributes more than 87% of total electricity generation and SUWTs less than 13% under optimised configurations; (2) Façade shaded length is the most influential geometric parameter. In Melbourne, Sydney, Brisbane and Perth, limiting shaded length to 20% enables a GHGe payback time below 8.3 years under gradual electricity-mix decarbonisation; (3) BIPV and SUWT outputs show partial seasonal complementarity, particularly in Melbourne and Sydney; (4) Life-cycle savings decline as electricity mixes decarbonise. In Adelaide, the cleaner electricity mix can increase the GHGe payback time beyond 25 years despite relatively high electricity output.
These findings demonstrate that the potential for tall buildings to operate as urban renewable electricity generation hubs depends jointly on local climate, urban shading conditions and the GHGe intensity of displaced grid electricity.