Permitting best use of wind resource for small wind-turbines in rural New Zealand: A micro-scale CFD examination

To maximize uptake of micro renewable-energy generation, specifically small wind-turbines, it is crucial to permit for tower heights which allow maximum utilization of the available wind resource. Within New Zealand, municipal governments have authority to place limitations on the height of built structures in rural areas, including wind turbines. Numerical simulations using Computational Fluid Dynamics (CFD) are used to examine the effects of simple house shapes and heights on the characteristics of the air flow reaching wind turbines. Within New Zealand, municipal governments have authority to place limitations on the height of built structures in rural areas, including wind turbines. However at present they have insufficient information to understand which height limitations may decrease wind-resource utilisation by small wind-turbines installed in these areas. This research finds that current permitted structure heights are not sufficiently high, necessitating either lengthy planning consent processes or acceptance of sub-optimal turbine output. Municipal councils in New Zealand could reduce barriers to small wind-turbine installations by considering taller towers, in the 15–20 m range, acceptable. This 15–20 m range is transferrable to all rural areas, in other developed or developing countries, where a lone small turbine or small number of small wind-turbines are being considered for installation near dwellings.