Highway corridors represent an underutilized opportunity for distributed renewable energy generation. As transportation networks increasingly require power for lighting, signaling, and monitoring systems, researchers have examined whether vertical-axis wind turbines (VAWTs) can harvest both ambient winds and the slipstream created by moving vehicles to generate on-site electricity.
A comprehensive review of highway-integrated VAWT technology synthesizes findings from field measurements, computational fluid dynamics modeling, and deployment studies. Natural winds along highways typically range from 2 to 6 meters per second, with occasional gusts, while vehicle traffic at speeds of 38 to 107 kilometers per hour generates intermittent wake flows that can exceed turbine cut-in thresholds near the roadway.
Critical design factors emerged from field trials. Median placement of turbines generally outperforms shoulder mounting, producing higher rotor speeds and electrical output. Self-starting Savonius and hybrid Savonius-Darrieus rotor designs demonstrate superior tolerance to turbulent, bidirectional flows compared to conventional lift-type rotors, which often struggle to initiate rotation under chaotic highway conditions. CFD analysis explains these performance differences by correlating turbine behavior to wake structure and traffic patterns. Vehicle convoys moving in the same direction sustain more consistent inflow, whereas opposing flows may partially cancel beneficial wind effects.
While flow control devices and turbine arrays show theoretical promise for performance enhancement, real-world validation under actual highway conditions remains limited. Techno-economic assessments reveal that wind-only systems are economically viable only in niche, low-cost applications. Hybrid photovoltaic-wind and photovoltaic-LED configurations deliver more consistent returns and temporal reliability, making them more attractive for practical deployment.
The review identifies significant research gaps: insufficient long-duration field datasets with standardized measurement protocols, incomplete reporting of efficiency and system losses, and inadequate integration of aerodynamic, electrical, and structural modeling with safety, maintenance, and environmental constraints. Future work must address these gaps and establish scalable, safe implementations that respect right-of-way regulations.
