Economic evaluation of any proposed commercial wind farm requires understanding its sub annual production and revenue risk profile. Merchant and hedge contracts account for roughly one third of contracted financial structures enabling wind farm installations with the rest being contracted under power purchase agreements (PPAs). While PPAs are still the preferred means of transacting generation, PPAs have become more complex as the pool of off takers and their respective commercial needs have become more diverse exposing wind farm projects to commercial risks such as basis risk. These facts underlie the importance of accurately modeling wind farm generation on a sub annual, time series basis. Standard wind resource assessment methodology is generally performed on a time series basis except when modeling spatial wind resource and energy efficiencies at wind turbine locations. Time series energy efficiency modeling methods are largely peripheral, relative analyses that provide energy efficiency estimates as inputs to a calibrated, bin-wise modeling methodology. In this session we will hear industry experts discuss time series energy modeling methods they have developed and validated in attempt to make time series energy analysis less of a peripheral tool and more of a primary means of conducting standard wind resource assessments.