Impact of Distributed Generation on PV Variability: A Lanai Case Study

Variability in Photovoltaic (PV) generation resulting from variability in the solar field is an area of continuing concern for those involved with integrating renewables onto existing electrical grids. Islands such as Lanai, Hawaii are an extreme example of the challenges that will be faced by integrators due to the fact that it is a small standalone grid. Among the numerous ways to study this problem is to take high-resolution solar measurements in multiple locations and model simultaneous PV production for various sizes at those locations. The National Renewable Energy Laboratory (NREL) has collected high-resolution solar data at 4 locations on the island where PV will be potentially deployed in the near future (Figure 1). This dataset provides unique insight into how the solar field may vary between points that are proximal in distance but diverse in weather due to terrain impacts. Using information about the proposed capacity of the distributed PV output was created at high resolution. This output was then analyzed to understand power production ramps at individual locations and the effects of aggregating the production from all four locations. Hawaii is a unique environment with extremely variable events occurring on a daily basis. This study provides an excellent opportunity for understanding potential worst-case scenarios for PV ramping. This paper will provide an introduction to the datasets that have been collected over a year and a comprehensive analysis of PV variability in a distributed generation scenario.