A vehicle charger is a demand charge waiting to happen
SRP's Customer Generation price plan has a per-kilowatt demand charge based upon your usage of energy supplied by SRP, calculated on 30-minute intervals during on-peak hours. A home vehicle charger is one of the largest single loads a household has.
Plug in at 6 p.m. in January or 5 p.m. in July and you may set the demand charge for the entire month in a single half hour, regardless of how careful you are the rest of the time. That is the mechanism, and it catches people who are otherwise diligent about their usage.
On-peak hours are weekdays from 5 to 9 a.m. and 5 to 9 p.m. from November through April, and weekdays from 2 to 8 p.m. from May through October. Scheduling charging outside those windows is free, requires no equipment, and is the single highest-value habit available to an SRP customer with a car.
Most vehicles and most chargers can be scheduled. Set it once, verify it actually behaves as configured over a couple of billing periods, and check it again after any software update, because a charger that quietly reverts to charging on plug-in undoes the whole arrangement.
The same car is the best home for your production
Exported solar is credited below the retail rate, and on the Customer Generation plan excess energy is instantly exported and credited at a fixed price of 3.45 cents per kilowatt-hour. Electricity you consume as it is generated avoids a retail purchase instead, which is worth considerably more.
A vehicle is a large, flexible, schedulable load, which makes it close to the ideal way to soak up midday production that would otherwise leave the house for 3.45 cents. Charging while the sun is high converts low-value exports into avoided purchases.
That does need daytime access to the charger, which suits a household with someone home, a hybrid working pattern or a car that sits at home on weekdays. If the vehicle is away every day, the honest answer is that the opportunity is smaller, and a good installer will say so rather than model it anyway.
SRP also publishes an Electric Vehicle Export Price Plan for solar customers alongside its other solar plans. Ask SRP how it compares with the Customer Generation plan for a household like yours, since a car is exactly the circumstance that plan exists for.
Sizing a system around a car
A vehicle raises household consumption substantially, which usually justifies a larger array than the same home without one. But the benefit only materialises if the charging happens when the array is producing, so the sizing case and the charging schedule are the same decision.
Ask your installer to model two scenarios: charging on a daytime schedule and charging overnight. The difference between them is the real value of the flexibility, and seeing it as a number makes the habit much easier to keep.
If you are planning to buy a vehicle later rather than now, say so before the system is sized. It is easier to design for a load you know is coming than to expand afterwards, and expansion can carry consequences of its own depending on your utility and arrangement.
Confirm which utility serves your address before any of this, since SRP serves much of the area and boundaries can change block by block. Verify by entering your address rather than assuming from your city.
The state credit you claim yourself, and the federal one that ended
Arizona still has a state income tax credit of its own, claimed on Arizona Form 310, Credit for Solar Energy Devices. It is calculated by multiplying the cost of a solar energy device by 25 percent, capped at $1,000, and the form provides for tracking credit carryover across multiple years.
Ask a tax advisor how the cap and the carryover apply to your situation before you rely on a figure in a quote. A credit is only worth what you can actually use against tax owed, and an installer is not the right party to advise you on that.
Arizona also exempts solar equipment from state sales tax and excludes it from property tax, so the improvement does not raise your property tax bill the way a renovation of similar cost would. Neither arrives as a cheque, which is exactly why they get left out of people's own arithmetic.
The federal position has changed and much published material has not caught up. The 30 percent Residential Clean Energy Credit under Section 25D expired for property placed in service after December 31, 2025, so a cash or loan purchase now does not receive it. Section 48E survives at 30 percent for third-party owners under leases and power purchase agreements, so such a provider may claim it and reflect part of the value in the rate offered. Ask what they claim and what actually reaches you, and confirm with a tax advisor.