Assessment of wind energy potential of buildings by CFD simulation in dense urban environments - From Case Studies to a Dendrogram-Based Design Framework

Abstract

Building-integrated wind turbines (BIWT) remain under-deployed in dense European urban contexts despite their potential contribution to net-zero energy targets. This paper presents a measurement-validated computational fluid dynamics (CFD) framework to identify optimal locations for micro-wind turbines on the envelopes of dense Parisian Haussmannian blocks. The methodology couples a multi-month on-site anemometry campaign on two case-study buildings, a calibrated steady RANS digital twin using the realisable k-$ε$ turbulence model, and the introduction of an architecturally integrated accelerator wing -termed aerofoil -placed at the envelope edge to amplify and stabilise the local flow. Quantitative validation against year-long anemometer records yields a mean absolute percentage error (MAPE) of approximately 18 % and a hit-rate FAC2 above 0.85, meeting the COST 732 acceptance criteria for urban CFD models. On the {É}cole Nationale Sup{é}rieure d'Architecture Paris-Val-de-Seine (ENSAPVS) case study, the inter-tower configuration produces a directional speed-up factor of 3.4 (95 % CI 3.18-3.62) for the prevailing north-westerly sector at +70 m above ground; the addition of the aerofoil yields a further +13 % local speed-up, equivalent to +44 % in extractable power. A capacity-factor analysis based on the measured Weibull distribution and the Savonius rotor power curve estimates an annual yield of approximately 69 MWh, offsetting around 6 % of the building's annual electricity consumption -a substantially lower but more realistic figure than the cube-of-mean estimate. The findings are synthesised in a decision dendrogram that maps wind-rose typology, building plan, height and implantation onto recommended device families, providing architects and engineers with a transferable design-stage tool.