Improved Methodology for Typical Meteorological Year Month Selection Matching Annual Irradiance

Abstract

Long-term solar resource and weather data, and typical meteorological year (TMY) time series derived from long term observations, are key inputs for solar plant modeling and financing. In particular, PV plant analyses using single-year TMY data representing the 50th percentile (average) and 90th percentile are typically demanded by banks and other stakeholders. The standard methodology used to construct TMY series does not ensure that the selected months accurately match the annual resource values. This paper describes an improved month selection methodology to incorporate match to annual resource values as a criterion, resulting in improved overall fidelity of the TMY series in representing the underlying long-term data. This improved methodology has been applied to a satellite model dataset to produce 50th and 90th percentile data series throughout Saudi Arabia on a 0.1°x0.1° resolution grid to support solar industry stakeholders in the Kingdom.