Arizona

APS has two TOU rate plan options available for homeowners installing solar. The TOU rates determine what you are charged for electricity you consume from the grid. The current Resource Comparison Proxy determines what export credit value you are credited for excess solar sent to the utility.

Export Credits

Solar will first power your home avoiding purchases from the utility at the retail energy rate ($/kWh). Solar production not immediately consumed in the home, or stored in a battery, is exported to the grid for a credit.

APS customers are locked into the export credit value for 10 years. The RCP export credit value changes for new applicants every year on September 1.

Time of Use Rates

A) The default & most common rate is Time of Use 4pm-7pm Weekdays (TOU-E)

B) The alternative rate option is Time of Use 4pm-7pm Weekdays with Demand Charge (R-3)

Both available rates have a TOU structure which charge more for energy used during on-peak periods (4-7pm on weekdays) and less during off-peak periods (overnight, weekends, etc). Homeowners will want to limit energy usage during on-peak hours to maximize savings. Palmetto Lightreach recommends a TOU plan without demand charges for a more predictable utility bill with solar.

APS automatically enrolls you in Time of Use 4pm-7pm Weekdays (TOU-E) once your interconnection application is approved. If you would like to change it, please contact APS or select it in your online APS account.

All of APS’s rates and policies described herein are effective as of 5-1-2025.

For current rates and more information, please review APS Solar Plans.

SRP utility customers have several rate options, or price plans, available for homeowners installing rooftop solar. The price plans determine what you are charged for electricity consumed from SRP, and the rate you are credited for excess solar production sent to the grid.

All available rates have a Time-of-Use (TOU) structure which charges more for energy used during on-peak periods and less during off-peak periods. Two of the price plans have demand charges. Learn about demand

Homeowners will want to limit energy usage during on-peak hours to maximize savings under all the options, and consider pairing the system with battery storage. Palmetto Lightreach recommends a TOU plan without demand charges for a more predictable utility bill with solar.

All of SRP’s rates and policies described above are effective as of 5-1-2025.

SRP has proposed to adjust rates in November 2025.

For more information, please review SRP Solar Price Plans.

SRP has excellent resources on How to Save on Solar and Demand Price Plans.

TEP utility customers have several rate plan options available for homeowners installing solar. The rate plans determine what you are charged for electricity consumed from TEP. The current Resource Comparison Proxy determines what export credit value you will be credited for excess solar sent to the utility.

Export Credits

Solar will first power your home avoiding purchases from the utility at the retail energy rate ($/kWh). Solar production not immediately consumed in the home, or stored in a battery, is exported to the grid for a credit.

TEP customers are locked into the export credit value for 10 years. The RCP export credit value changes for new applicants every year on October 1.

Time of Use Rates

All available rates have a TOU structure which charge more for energy used during on-peak periods. TEP's on-peak hours are 3-7pm on Summer weekdays May-September, and 6-9am & 6-9pm on Winter weekdays October-April.

Homeowners will want to limit energy usage during on-peak hours to maximize savings. Palmetto Lightreach recommends a TOU plan without demand charges for a more predictable utility bill with solar.

TEP automatically enrolls you in TRREST Time-of-Use (no demand charges) once your interconnection application is approved. If you would like to change it, please contact TEP or select it in your online TEP account.

All of TEP's rates and policies described herein are effective as of 5-1-2025.

For current rates and more information, please review TEP Pricing Plans.

A demand rate charges a household based on total kWh (kilowatt hours) used throughout the month measured as $ per kWh, and also based on the highest aggregate electric usage at one point in time measured as $ per kW (kilowatt).

For example, if you had your air conditioner, lights, EV charging, hot tub, and more on all at once, even if just for 15 minutes, that could become your peak usage measurement for the whole month. With a demand rate schedule, you do not want to 'tower your power' instead spread out your consumption throughout the day and night.

Your utility will track your demand usage over each day of the month and multiply your highest peak demand, on any single day, by the demand charge ($/kW). Typical demand usage in a residential home in Arizona is 1-3 kW in the winter and 3-6 kW in the summer. Luckily, in Arizona, demand is measured as the highest usage during on-peak hours only.

For example, if your peak usage is 4 kWh for 1 hour during 1 day in the month, then your power is 4 kW. The summer rate in APS is $19.5/kW * 4 kW = $78!

Solar without battery storage is unlikely to reduce demand charges as one cloudy/rainy afternoon or solar system outage could cause peak demand use to spike and be the measurement for the entire monthly billing period.

Solar with battery storage can likely reduce peak demand charges if settings are used to dispatch stored energy to the home to prevent demand spikes. Fortunately, in Arizona, peak demand is only measured during on-peak hours, which means you could still charge an EV overnight without causing a demand spike.