Utility Plan Changes After Getting Solar – And How to Address Them

The Big Idea

When you go solar in Phoenix, your panels aren’t the only thing that changes.

For most homes:

• SRP moves solar homes onto a Customer Generation plan (E-27) with time-of-use pricing plus a demand charge. ¹
• APS pairs solar with time-of-use plans like Time-of-Use 4pm–7pm Weekdays with Demand Charge (R-3) or TOU without demand, plus a solar export rider (RCP). ²

That means your bill now depends on:

1. When you use power (off-peak vs on-peak hours)
2. How hard you hit the grid in your worst on-peak hour (your demand, in kW)
3. How much extra solar you export back to the grid (and what credit you get)

The goal of this post is to:

• Give a simple overview of how SRP and APS demand pricing in Phoenix work after you add solar
• Show where a Tesla Powerwall fits in
• Explain how Grid Getter can automate your Powerwall so you don’t have to think about it

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Quick Snapshot: What Changes After You Go Solar

Here’s the big picture, without drowning you in decimals:

Utility	After-solar plan type (typical)	On-peak window (weekdays)	What’s different from “old” flat plans
SRP	Customer Generation (E-27) – demand-based solar plan	Summer: 2–8 p.m.; Winter: 5–9 a.m. & 5–9 p.m. 3	Lower per-kWh prices, but new demand charge based on your highest 30-minute on-peak demand each month. 4
APS	Time-of-Use 4–7 p.m. Weekdays with Demand (R-3) or TOU without demand, plus RCP export rider	4–7 p.m. Mon–Fri; winter also has a 10 a.m.–3 p.m. “super off-peak” window. 2	Cheaper off-peak kWh, more expensive on-peak kWh, plus a demand charge based on your highest one-hour on-peak demand each month. 2

In both cases:

• Your off-peak kWh get cheaper than a flat plan
• Your on-peak kWh can be more expensive
• A demand charge now watches for your worst on-peak hour and bills you for that spike

That’s why people say:

“It’s not just how much energy you use anymore — it’s when and how spiky it is.”

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What This Means for a Typical Phoenix Home

The average Arizona home uses around 1,050–1,060 kWh per month, with an average bill around $165–$170 at roughly 15–16¢/kWh. ⁵

After going solar, two things usually happen:

1. You buy fewer kWh from SRP or APS
2. You move onto a demand-style plan

That creates three common stories.

1. “Solar + Good Habits = Nice Savings”

If you:

• Shift laundry, pool pump, and other big loads outside the on-peak window
• Avoid running everything at once during 4–7 p.m. (APS) or 2–8 p.m. (SRP summer)
• Let your solar and battery cover most afternoon usage

…then you:

• Use cheaper off-peak energy most of the time
• Keep your highest on-peak hour low, so demand charges stay reasonable
  • Still see lower bills than your old flat plan, even if export credits (what you get paid for extra solar) are only 3–7¢/kWh ⁶

2. “Solar + Normal Habits = Confusing”

If you:

• Add solar, but keep doing exactly what you always did
• Run AC, oven, dryer, and maybe EV charging at the same time in the peak window
• Don’t realize your plan now has a demand charge

…then you might see:

• Lower usage, but
• A stubborn or even higher bill because a single bad hour sets a big demand charge

This is where a lot of the “SRP/APS killed my solar savings” complaints come from.

3. “Solar + Time-Shift + Battery = Most Control”

If you:

• Shift flexible stuff (laundry, EV charging, pool) to off-peak or super off-peak
• Let a Tesla Powerwall handle most of your on-peak spikes
• Use something like Grid Getter to automate the whole thing

…then you:

• Buy fewer kWh and buy them mostly when they’re cheapest
• Keep your highest on-peak demand low and flat
• Turn demand pricing from a “gotcha” into something you can actually use to your advantage

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How a Tesla Powerwall Helps with SRP & APS Demand Pricing

A Powerwall is basically a rechargeable battery that:

• Stores solar you didn’t use immediately
• Can discharge during expensive hours
• Keeps your grid draw lower and smoother

Some Tesla specs:

Powerwall 2

• Usable capacity: ~13.5 kWh
• Continuous power: 5 kW (7 kW peak) ⁷

Powerwall 3

• Usable capacity: ~13.5 kWh
• Continuous power: 11.5 kW per unit ⁸

In plain English:

• A Powerwall 2 can hide a lot of your AC + cooking + dryer load from the grid during peak hours.
• A Powerwall 3 can often cover most of the home’s big loads at once through the 2–6 hour peak window.

So if your house is trying to pull:

• 10 kW total during a busy summer evening
• And your Powerwall 3 supplies 8–9 kW of that

Then the grid “sees” only 1–2 kW, which can dramatically reduce your SRP or APS demand charge.

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Where Grid Getter Fits In

A Powerwall is powerful hardware, but it doesn't consider strategy:

• It doesn't consider where you are your on-peak period
• When it's active it drains, even during off-peak periods (consider a cloudy day)
• It'll discharge until it hits your set limit, regardless of additional peak need
• It leaves you in the dark of it's status and charge level

That’s where Grid Getter shines especially for SRP and APS demand pricing in Phoenix:

1. Understands Your Entire Peak Period

   • It monitors throughout your set peak peroid
     • Syncs with your utility’s billing interval (30- or 60-minute) so your system targets the right timeframe. 

2. Coaches your Tesla Powerwall

   • You set and forget automations for your Powerwall settings
   • Intelligently portions out energy from the grid and battery to minimize your demand price, not just randomly shave load

3. Keeps you Informed (Open Beta)

• Using our companion notification apps (iOS and Android), you stay notified about your system:
  • Automation run notifications
  • Battery level alerts
  • Battery anomaly alerts (if your charge is abnormal for the time of day)

So instead of you staring at the Tesla app and SRP/APS rate sheets every afternoon, Grid Getter + Powerwall act like your personal energy autopilot.

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Try Us Out

If you’re:

• Already on an SRP or APS solar plan and wondering why your bill feels weird, or
• Planning solar and want to understand the impact of demand pricing before you sign anything, or
• Adding a Tesla Powerwall and want it to do more than just sit there as backup…

Then this is exactly what Grid Getter is built for.

👉 See the savings for yourself — create a free Grid Getter account to view a personalized estimate.

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Appendix: SRP & APS Rate Details (For Number Nerds)

You don’t need these numbers to use Grid Getter, but they help explain what’s going on under the hood.

A. SRP “Customer Generation” (E-27) – Energy Rates

SRP’s own solar plan comparison shows Customer Generation energy prices roughly like this: ⁹

Energy charge only, cents per kWh (rounded)

Season	Time period	Approx. price (¢/kWh)
Winter (Nov–Apr)	On-peak	6.74¢
	Off-peak	6.34¢
Summer (May/Jun/Sep/Oct)	On-peak	6.62¢
	Off-peak	5.60¢
Summer Peak (Jul–Aug)	On-peak	8.23¢
	Off-peak	6.13¢

On-peak windows for solar plans:

• Summer: 2–8 p.m. weekdays
• Winter: 5–9 a.m. and 5–9 p.m. weekdays ³

SRP’s Customer Generation also has a demand charge based on your highest 30-minute on-peak demand each month. Prices step up in tiers (first few kW at one price, the rest higher). ⁴

SRP’s separate TOU Export plan (no demand charge) credits exports at about 3.45¢/kWh. ⁶

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B. APS TOU 4–7 Weekdays with Demand Charge (R-3)

APS’s R-3 plan is a common pairing with rooftop solar and the RCP export rider. Its time periods: ²

• On-Peak: 4–7 p.m. Mon–Fri
• Super Off-Peak (winter only): 10 a.m.–3 p.m. Mon–Fri (Nov–Apr)
• Off-Peak: All other hours + designated holidays

Independent analyses of the R-3 tariff show approximate energy charges like: ¹⁰

Energy charge, cents per kWh (rounded)

Season	Period	Approx. price (¢/kWh)
Summer	On-peak	14.23¢
	Off-peak	5.94¢
Winter	On-peak	9.93¢
	Off-peak	5.94¢
	Super off-peak	3.50¢

Demand charges on this plan: ²

• Summer demand charge: $19.585 per kW
• Winter demand charge: $13.747 per kW
• Billed on your highest one-hour average during any on-peak hour in the month

APS’s RCP export rate (what you earn for extra solar you send to the grid) is currently about 6–7¢/kWh for new customers, with one example at $0.06857/kWh in 2025. ¹¹

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C. Why Demand + TOU + Export Credits Feel So Weird

When you put it all together:

• Off-peak energy can be roughly 6¢/kWh
• On-peak energy might be 10–16¢/kWh
• Export credits are 3–7¢/kWh
• Demand charges can add $20 per kW in summer for APS, and multi-tiered $/kW charges for SRP ¹²

So your bill outcome depends on:

1. How many kWh you still buy
2. When you buy them
3. Whether your worst on-peak hour is 2 kW, 5 kW, or 10+ kW
4. How much of your solar you self-consume vs export

That’s exactly the problem Grid Getter is built to solve:
turning SRP and APS demand pricing in Phoenix into something your Tesla Powerwall + automations can manage automatically, so you don’t have to think in cents per kWh or dollars per kW at all.

Sources

¹: SRP — Customer Generation plan (E-27)
²: APS — R-3 Time-of-Use with Demand (PDF)
³: Solar Topps — SRP solar rate plans overview
⁴: SRP — E-27 Ratebook (PDF)
⁵: Jackery — What is the average electric bill in Arizona
⁶: SRP — TOU Export plan (credits)
⁷: Tesla — Powerwall 2 datasheet (PDF)
⁸: Tesla — Powerwall product page
⁹: SRP — Compare solar plans
¹⁰: Inergy Systems — APS R-3 analysis
¹¹: Sun Valley Solar Solutions — Going solar with APS
¹²: APS — Service Plans FAQ