Estimating the wind resource in an urban area: A case study of micro-wind generation potential in Dublin, Ireland

Abstract

The micro-turbine wind market in cities faces significant challenges due to the complexities associated with the urban terrain but, if a renewable solution to increasing energy demand is to be achieved, energy conversion systems where populations are concentrated, that is cities, must be considered. This research evaluates the urban wind resource by employing a physically-based empirical model to link wind observations at a conventional meteorological site to those acquired at urban sites. The approach is based on urban climate research that has examined the effects of varying surface roughness on the wind-field between and above buildings. Here, this is applied to link observations at Dublin Airport, outside the urban area, to those made at an urban and suburban site in Dublin where instruments were placed near roof-level and well above roof height. The log model to describe the vertical wind profile is tested against observations made over the course of a year. It is shown to have sufficient accuracy to assess the potential for micro-turbine energy generation in cities and illustrates that the urban wind resource can be evaluated from measurements made at a nearby site, adjusted for the urban site location. HighlightsThe article investigates if a viable wind resource, worth exploiting, exists at an accessible height above a city (Dublin, Ireland) Urban climatology and the simple logarithmic profile, are employed to successfully extrapolate the wind resource at the city Airport into an associated suburban and urban location, to a height between 1.5 and 2 times the respective average building height at both locations The analysis shows that in conjunction with urban surface roughness, the urban frictional velocity must also be considered for urban wind resource modelling Other models are utilised to investigate the nature of the wind resource below the recognised lower limit of the logarithmic profile, namely the power law and a methodology primarily developed for urban air pollution modelling The research is provided a renewable energy context by considering the productivity of a commercially available wind generator. The results show that the wind resource available at roughly twice the average building height at either an urban and suburban location is worth harnessing, but within a very short height reduction, the wind resource depletion renders the consideration economically unviable.

Small wind turbines in turbulent (urban) environments: A consideration of normal and Weibull distributions for power prediction

“…As a consequence of heat output from the city, urban climates tend to be more unstable than neutral [12]. However, as discussed in [13] for the sites considered in this research, it was ascertained that at Dublin Airport (circa 10km from Dublin city centre), 86% of data for the period November 2010 to December 2011…”

“…SUB1 has a more consistent building morphology and the anemometer is surrounded by a relatively lower average building height that consists mostly of two-storey residential buildings and vegetation which is also at similar heights. Figure 3, which is modified from [13], presents a context for both sites, where detailed analysis of the wind resource in an urban environment is considered . At both sites, high-resolution wind speed measurements are taken with a Campbell Scientific CSAT3 threedimensional sonic anemometer [35].…”

Linking urban climate classification with an urban energy and water budget model: Multi-site and multi-seasonal evaluation

“…The first site, Dublin Ireland -DUB -the flux observations are made on a mast located in a recently instrumented flat rooftop located on the grounds of a technical institute, just south of the centre of the urban area amidst a mix of dense commercial units and residential apartments (Sunderland et al, 2013;Keogh, 2015). The buildings surrounding the flux site are between 15 and 20 m tall, compact spacing with little vegetation.…”

The progressive development of turbulence statistics and its impact on wind power predictability

“…conditions where buoyancy, which is sensitive to temperature stratification, is less influential and cloudy skies and strong winds are prevalent [26]. Cloud reduces radiative heating in this regard and cooling of the surface with strong winds promoting mixing without strong temperature stratification turbulence in a neutrally buoyant climate tends to be predominantly influenced by wind negotiating real world objects thereby changing direction and wind speed.…”