Avista Rate Case

Washington Office of the Attorney General
Project completed 2018

Synapse’s Rachel Wilson provided analysis and testimony on an Avista Corporation rate case before the Washington Utilities & Transportation Commission. Ms. Wilson evaluated Avista’s production cost modeling, which used the AuroraXMP model, to determine if its requested increase in power costs was reasonable. She found that Avista’s modeling methodology led to a sustained overestimate of annual power supply costs, as evidenced by the compounding of credit deferral balances in its Energy Recovery Mechanism. Ms. Wilson recommended that Avista recalibrate its modeling to allow the Energy Recovery Mechanism to function as intended—to capture the variability between modeled and actual power supply costs. She further recommended that Avista more fully explore the possibility of joining the Western Energy Imbalance Market, which is a real-time wholesale energy market in which participants can buy and sell energy when needed.