Regional variability in New Zealand's wind resource linked to synoptic-scale circulation: Implications for generation reliability

Abstract

Even in locations endowed with excellent wind resources, the intermittent nature of wind is perceived as a barrier to reliable generation. However, recent studies have demonstrated that electrically interconnecting wind farms in a meteorologically oriented network can reduce supply variability and the observed frequency of zero-generation conditions. In this study a 5-yr synthetic dataset of 15 wind farms is utilized to investigate the benefits to supply reliability from wind farm interconnection in New Zealand. An examination is carried out primarily through a synoptic climatology framework, hypothesizing that benefits to reliability are primarily related to the degree to which wind farms are influenced differently by the synoptic-scale circulation. Using a weather-typing approach and composite analysis, regionality is observed in the linkages between synoptic-scale circulation and wind resources, particularly between wind farms located in the far northern and far southern regions of the country. Subsequently, and as compared with all other possible combinations, supply reliability is observed to be optimized in a network that includes wind farms connected between far northern and far southern regions, under which the frequency of hours with zero generation is almost eliminated. It is likely that the frequency of hours with zero generation could be further reduced on the basis of a more extensive meteorologically based selection of wind data from a greater number of locations. It is suggested that these findings should be taken into consideration in future planning and site selection of wind farm projects in New Zealand.