Changes in the electric utility resource mix are being implemented at an accelerated pace. Increasing levels of Distributed Energy Resources (DER), including customer-owned solar, solar facilities, energy storage and wind are happening across the country. Planning in this environment is much more challenging, as both utility and customer resources are changing.
PSE’s planning process involves defining future scenarios with varying levels of specific types of resources. Evaluating the resource mix for each scenario provides an opportunity to see how well it provides for the overall resource need, and whether the resource mix would result in excess energy, or a shortfall of energy when addressing the central planning objective of meeting customer energy needs. Impacts on power supply costs, delivery system needs, transmission service costs, and rate design can all be included in the evaluation, depending on the depth of evaluation that is desired. The range of scenarios can also provide a “no regret” development path for any initiative that is considered a means of providing resources for a range of scenarios.