AURORA is a proprietary model[1] the Council uses for forecasting wholesale electricity prices and projecting the buildout of the western grid outside the region. The model is populated with a database that is supplemented from the generating resources database and WECC anchor dataset. The Council uses two primary functionalities from the AURORA software: Mixed Integer Programming Long Term Capacity Expansion and Commitment Optimization Logic.

The mixed integer programming long term capacity expansion primary function is to use a mixed integer programming logic to make resource build and retirement decisions. The Council uses the resource build decisions to represent a likely buildout for the western grid to ensure price simulations for future years represent a power system that is broadly adequate and meeting policies. The Council studies do not currently use the economic retirement logic.

The commitment optimization logic used a mixed integer linear program to determine hourly unit commitment for all the generators in the western grid. This logic co-optimizes the use of resources for energy dispatch and provision of ancillary services by clustering resources and demand in zones connected by an energy transfer capability.

Modifications to the default setup were discussed in detail in the System Analysis Advisory Committee during the buildup to the plan. 

[1] Licensed from Energy Exemplar