for each circuit over a five-year forecast horizon. The distribution deferral opportunity report represents the estimated range for system upgrade needs in the corresponding time horizons. Assessing the Contribution of DERs to Peak Load In late 2013, SCE launched the Preferred Resource Pilot (PRP) in the southern region of its territory to determine whether locally deployed DERs can reliably serve the forecasted load growth for 2022. The area where the PRP is implemented is served by two 230/66-kV substations, covers 13 cities, and provides approximately 250,000 customer accounts. The peak load is driven primarily by commercial and industrial customers. Portfolio Design The PRP implementation is illustrated in Figure 2, including the portfolio design process. This annual process determines the type and number of preferred resources that can most effectively meet the forecasted load needs subject to the figure 1. A snapshot of SCE's distribution resources plan's external portal, showing the grid needs assessment data for a real 12-kV circuit (highlighted in blue). Forecast Load Growth Measurement Cycle Repeats Based On New Data Development of Forecasted Hourly Load Shapes and Preferred Resources Attributes Determine Preferred Resources Selections for Portfolio Options Perform Market Potential Study for Preferred Resources Options PRP Portfolio Design Process figure 2. SCE's PRP implementation. 30 ieee power & energy magazine july/august 2021 Acquisition