The Rise of Demand Charges in California: What SCE and SDG&E Customers Need to Know

California's electricity pricing has always been complicated. But what SCE and SDG&E are doing right now is different — it's shifting cost risk onto homeowners in ways that don't show up obviously on your bill, even for those with solar and batteries.

If you're a Powerwall owner on the grid in Southern California, here's what's actually changing and why it matters more than your current bill might suggest.

SCE's TOU-D-PRIME: Energy Pricing That Behaves Like a Demand Charge

SCE's TOU-D-PRIME isn't technically a demand charge. There's no line on your bill that says "peak kW demand: $X." But the way it's structured, punishing you hard for energy pulled during a narrow peak window, creates almost the same financial pressure.

The peak window runs 4–9 PM, and during summer months (June through September), SCE's TOU-D-PRIME on-peak rate sits around $0.59/kWh as of spring 2026 — verify the current figure against SCE's approved rate schedule at sce.com before making financial decisions. Off-peak drops to roughly $0.24–0.26/kWh. That's more than a 2x multiplier. Run your dishwasher or charge your EV during those five hours and you're paying premium prices for every single kilowatt-hour.

Compare that to how Arizona demand charges work. On SRP's E-27 plan, you pay based on your highest 30-minute average kW draw during peak hours — one bad afternoon spike and you're paying $14.50 per kW for the entire month in summer (May–October), regardless of how disciplined you were the other 29 days. Winter demand rates drop to around $10.50/kW. It's brutal, but it's transparent. You know exactly what you're managing against.

TOU-D-PRIME is subtler. Instead of a single spike to avoid, you have a 5-hour window every weekday where every kWh costs double. If your Powerwall runs down by 6 PM and your HVAC kicks in at full load, you're paying peak rates for two or three hours of grid pull.

The Super Off-Peak Window Is the Flip Side

TOU-D-PRIME does give you something back: a super off-peak window during winter months (October through May, typically 8 AM to 4 PM on weekdays) where rates sit around $0.24/kWh (super off-peak window definitions have shifted in recent rate cases — confirm the current schedule at sce.com). That's a genuine charging opportunity for Powerwall owners, especially paired with solar production during those daytime hours. The rate structure is essentially asking you to shift consumption as aggressively as possible: charge batteries cheap, discharge during peak. The problem is doing that reliably, every day, while also reserving capacity for real-time household demand and the unexpected.

SDG&E's Fixed Fee: Around $24/Month for Standard Customers

SDG&E customers are dealing with something different: a mandatory fixed monthly connection fee implemented under California AB 205. For standard (non-CARE) customers, that fee runs approximately $24 per month ($0.79/day) — the same ballpark as PG&E and SCE under the same law. CARE and FERA customers pay significantly less under the income-graduated structure, so what you actually see on your bill depends on which program you're enrolled in.

That fixed charge hits before you've used a single kilowatt-hour.

Do the math on what your Powerwall needs to offset just to break even on that fee alone.

At SDG&E's off-peak rate of around $0.47–0.48/kWh, you'd need to displace roughly 50 kWh of grid consumption per month just to cover the fixed charge. That's before you see any net savings. A standard 13.5 kWh Powerwall cycling once per day gives you around 360–370 kWh of usable throughput monthly, accounting for roughly 90% round-trip efficiency. So in theory, you have room to cover it several times over — but only if that battery is actually discharging at the right times.

The fixed fee also changes the calculus on low-usage months. If you've got solar and batteries and your variable charges are already low, the fixed $24 becomes a larger percentage of your total bill. It can't be reduced by efficiency or solar production. It's just there. Which means the only way to offset it is to extract more value from your Powerwall during peak and mid-peak windows on the variable-rate side.

SDG&E's peak rates (typically 4–9 PM, weekdays) currently run around $0.62–0.70/kWh on their TOU plans. Every hour you keep your home off the grid during that window is real money, and it's the only lever you have against a fixed fee you can't eliminate.

Virtual Power Plants: Real Money, But Real Tradeoffs

Both SCE and SDG&E run Virtual Power Plant programs, where your battery exports power back to support the local grid during high-demand periods. SCE's Emergency Load Reduction Program (ELRP) and SDG&E's ELRP A.4 and Demand Side Grid Support (DSGS) programs can pay out meaningful credits: typically around $2 per kWh exported during events for ELRP, though rates are program-specific, seasonal, and subject to change — confirm current terms at sce.com and sdge.com before enrolling.

The catch is timing. VPP events are called during high-grid-stress periods, almost always summer afternoons between 4 and 9 PM — the exact window when you most need your battery for your own peak-hour defense.

If Grid Getter dispatches your full battery into a VPP event at 4 PM and the event runs two hours, you might earn $20–27 in grid credits. But if your home draws 3–4 kW for the remaining three hours of the peak window from the grid at $0.59/kWh, you've spent $5–7 on grid energy. Still a net win, but not if you didn't account for it.

Grid Getter tracks VPP event eligibility and pre-positions your battery accordingly. If an event is signaled, the system checks your current state of charge and whether recent consumption patterns make participation worthwhile before committing. The goal isn't to always say yes to VPP; it's to say yes when it's actually the right call and hold reserve when it isn't.

That's not something you can manage manually at 4:03 PM on a Tuesday.

Why Manual Management Breaks Down Here

Arizona SRP customers managing E-27 demand charges have a cleaner problem: identify your peak 30-minute window, keep kW draw low, done. That's hard to do manually, but at least it's one number to optimize.

California is different. SCE TOU-D-PRIME has energy rates that shift across four pricing tiers depending on time of day, month, and weather. SDG&E layered a fixed fee on top of a TOU structure that itself has multiple tiers. VPP events add another variable. Seasonal rate changes happen twice a year. And your solar production changes every day based on sun hours, cloud cover, and whether your panels are dirty.

On any given day, your Powerwall might need to hold reserve for the evening peak window and export into VPP if an event triggers — while somehow also recharging during the super off-peak window. No static app setting handles that well. You'd need to re-optimize constantly.

Grid Getter's utility-aware scheduling pulls your specific rate plan (TOU-D-PRIME, TOU-D-4-9PM, DR-SES, whatever you're on), maps your peak windows, and schedules Powerwall charge/discharge cycles around the actual rates you're paying. The DemandGuard feature monitors real-time consumption during your peak window and can reduce Powerwall backup reserve thresholds dynamically when grid conditions make it safe, so you're not leaving stored energy sitting unused while paying peak rates to run your fridge.

The dashboard shows you what you're actually saving against each fee structure, including the fixed connection charge offset. You can see month-to-date savings against your baseline, peak-hour avoidance totals, and VPP event earnings in one place, so it's easier to tell whether your setup is working or something needs adjustment.

Getting Started

If you're on SCE and haven't confirmed whether you're on TOU-D-PRIME or a legacy rate plan, log into your SCE account and look for "Rate Plan" under your account summary. If you're on an older non-TOU plan, SCE has been migrating customers automatically. You may have been switched already.

For SDG&E customers, find your current fixed charge on your bill under "Basic Service Fee" or "Customer Charge." Standard (non-CARE) customers are likely seeing around $24 per month under AB 205. CARE and FERA customers will see a lower graduated amount. If you're not seeing a fixed charge yet, it's likely coming in your next billing cycle.

Grid Getter has a free tier that covers utility-aware scheduling and basic peak avoidance for both SCE and SDG&E customers. If you want the dashboard tracking and VPP integration, paid tiers start after you've had a chance to see what the free version does. Sign up at gridgetter.com/free/.

The one thing to check today: Pull up your last bill and find your peak-hour energy consumption. On SDG&E that's usually broken out by TOU period. On SCE, look for the on-peak kWh line. That number, whatever you pulled from the grid between 4 and 9 PM, is your baseline. That's what your Powerwall should be eliminating, and it's the clearest measure of whether your current setup is actually working.