Presentation Description: Time-series energy modeling represents the next frontier of wind plant design and energy estimation. It has the advantage of generating more realistic plant losses based on time-varying environmental conditions than existing methods based on static frequency distributions. We’ve been using the newly developed API in Openwind to perform time-series energy modeling at approximately 60 operational wind farms in North America. Historical time series of wind power production and associated plant losses were generated for the 1980-2018 period. The long-term, hourly meteorological time series were created with the Weather Research and Forecasting (WRF) model initialized by the ERA-Interim reanalysis data set. The meteorological time series were then converted into wind power generation with the Openwind software, taking into account plant losses on an hourly basis. All plant losses were tracked separately and at the turbine level which corresponds to major improvements over previous approaches. New methods were developed inside the Openwind software to simulate the time-varying plant losses, e.g. wakes, availability, environmental, electrical, turbine underperformance. The hourly net power time series were compared against the actual power generation from operational wind farms. The validation of the modeled net power generation at the operational plants included the standard error metrics (bias, MAE and RMSE) in addition to a close look at the annual, monthly and diurnal profiles, ramp distribution, duration curve, etc. Strong agreement is observed between the actual and modeled net power generation, despite the added complexity of icing-related losses.