RESOLVE is a resource investment model that identifies optimal long-term generation and transmission investments in an electric system, subject to reliability, technical, and policy constraints. Designed in 2014 to assess the investment needs of systems seeking to integrate large quantities of variable renewable resources, RESOLVE adds capacity expansion logic to a simplified production simulation model to estimate an optimal investment plan, accounting for both the capital costs of new resources and the variable costs of reliably operating the grid.
In an environment in which most new investments in the electric system have fixed costs significantly larger than their variable operating costs, this type of model provides a strong foundation for identifying the benefits associated with alternative investment plans. Multiple studies have used or are currently using this model.
- For Hawaiian Electric Company’s Power Supply Improvement Plan, E3 used RESOLVE to explore which investments would allow the islands of Hawai‘i, Maui, and Oahu to meet 100 percent renewable goals by 2045.
- In ongoing integrated resource planning, the California Public Utilities Commission is using RESOLVE to develop a system plan to meet state policy goals and GHG emissions reduction targets through the optimization of the renewable portfolio and integration solutions.
The California ISO’s study for Senate Bill 350 used RESOLVE to identify how expansion of the ISO footprint would provide ratepayer benefits through savings on the fixed costs of new investments in renewables, transmission, and energy storage.