SRP Updates E-27 Solar Rate Plan: New Demand Charges and Strategies to Maximize Savings

Salt River Project has issued updated rates for its E-27 solar plan effective April 1, 2026, the primary rate schedule for SRP residential customers with rooftop solar. The revised plan retains SRP's controversial demand charge structure but adjusts the demand measurement window: demand charges will now be assessed on the highest 15-minute interval of import from the grid between 5 PM and 9 PM on weekdays rather than the previous 30-minute window, making peak demand spikes more costly. The base demand charge remains at $18.87 per kW per month of peak demand. Export compensation under E-27 is set at $0.029 per kWh, unchanged. A homeowner who imports even briefly at 3 kW during the evening peak pays $56.61 in demand charges that month regardless of total solar generation. Strategies to minimize demand charges include: sizing battery storage to fully cover the 5–9 PM peak window, setting EV charging to off-peak overnight hours, pre-cooling homes before the peak window using solar power, and using smart thermostats and load controllers that respond to grid signals. SRP serves approximately 1.1 million customers in the greater Phoenix area and operates outside Arizona Corporation Commission rate-setting authority as a political subdivision, meaning customers cannot appeal its rate structures to state regulators. Customers dissatisfied with E-27 may switch to APS service territory only if they relocate.