By AWS Solar, a licensed C-10 solar and electrical contractor serving Los Angeles and Ventura County since 2007
You just turned on your solar and Powerwall 3, and you have Permission to Operate (PTO). Now, the Tesla app asks you to choose an operational mode, export setting, and backup reserve. When you search for “the best settings,” you find lots of confident but conflicting advice.
To give you an idea of what this looks like in practice, here’s a quick setup example for a typical SCE homeowner:
– In the Tesla app, set your utility rate plan to match your SCE bill—let’s say TOU-D-4-9 PM.
– Choose Time-Based Control as your operational mode, which prioritizes saving power for the expensive evening hours.
– Set the permission to export option to “YES”.
– Set your backup reserve to 20% to balance outage protection with daily savings.
You can tweak these settings over time, but this basic approach works well for many homes and gets you started with confidence.
Most blogs won’t tell you this, but there isn’t one “best” setting. The right setup depends on your rate plan, interconnection date, system size compared to your usage, and your priorities—whether that’s saving money, staying powered during outages, or both. Anyone offering a universal answer is just guessing.
We can give you a framework. If you understand the four decisions below, you’ll be able to set up your own system and know what questions to ask your installer when needed.
The four settings that matter
- Your utility rate plan (set this first, or everything else is wrong)
- Your operational mode: Self-Powered or Time-Based Control
- Your backup reserve percentage
We’ll take them in order.
1. Set your rate plan correctly. This is the step most people skip.
Before you touch any mode, open the Tesla app and confirm your utility rate plan is set to your actual SCE schedule. This sounds obvious. It is the single most common mistake we see.
If you’re on TOU-D-PRIME, TOU-D-4-9 PM, TOU-D-5-8 PM, or another time-of-use plan, your Powerwall needs to know which plan you’re on. Time-Based Control uses the price difference between your peak and off-peak hours to make decisions. If the app thinks you’re on a different plan, or even a flat rate, it will use the wrong numbers, and you could lose money without realizing it.
Action: In the Tesla app, check your energy site settings and make sure the utility and rate plan match your latest SCE bill. If you’re not sure which plan you have, look at your bill or ask your installer to confirm.
2. Operational mode: Self-Powered vs. Time-Based Control
This is the decision people agonize over. Here’s how to actually think about it.
Self-Powered does what it sounds like: it tries to run your home on your own solar and battery as much as possible. Excess solar charges the battery during the day; the battery powers your house whenever solar isn’t enough. It does not take the time or your rate plan into account.
Time-Based Control (TBC) optimizes around your time-of-use rates. It holds the battery’s charge so it’s available during your expensive peak window (for most SCE customers, that’s roughly 4 p.m. to 9 p.m.), then discharges hard during those hours to keep you off the expensive grid.
The key difference: when the battery charges
This is the part most guides get wrong. The two modes don’t just discharge differently—they charge differently and on a completely different schedule.
Self-Powered charges earlier from solar. The moment your panels produce more than the house is using, that surplus goes straight into the battery. By late morning on a sunny day, the pack is often already full, and only then does the excess begin to flow to the grid. It banks the charge first and exports the leftovers.
Time-Based Control defers charging. Instead of filling the battery from your morning solar, TBC tends to export that early production to the grid and charge the battery later in the day — timing the pack to hit full right before your peak window starts. It’s making a forecast-based bet: “I’ll export now and count on enough afternoon sun to top off before 4 p.m.”
That difference matters for two real reasons:
- Export timing has dollar consequences under NBT. Because TBC exports your morning solar and Self-Powered exports your midday surplus, the two modes sell energy at different times, and under NBT, each hour has a different export value. Tesla’s algorithm doesn’t perfectly account for SCE’s actual value curve (more on that in the export section below), so which mode comes out ahead isn’t automatic.
- TBC’s forecast bet can be wrong. If the day turns cloudy after TBC has already exported your morning solar, the pack may not fully recharge before peak — leaving you to buy expensive grid power in the evening. Self-Powered doesn’t take that risk; it’s a bird in the hand. This is why TBC’s edge shows up most on short winter days and unpredictable weather — and also why, on those same days, it can occasionally backfire.
So which one?
For most SCE customers on a 4–9 p.m. peak plan, Time-Based Control is the reasonable default, because protecting the charge for the peak window is usually worth it. But it’s a genuine judgment call, not a slam dunk. Self-Powered’s “charge first, ask questions later” behavior is more conservative and more predictable, and some owners prefer it for exactly that reason. The right answer depends on your rate spread, how consistent your local weather is, and how much you value predictability over squeezing out the last few percent.
And no mode fixes a capacity problem: if your battery regularly runs dry before 9 p.m. because it’s simply too small for your evening load, that’s a sizing issue, not a settings issue. No mode setting can stretch a battery that doesn’t have the capacity.
3. Backup reserve: balancing safety and savings
Your backup reserve is the percentage of the Powerwall’s battery capacity yourit keeps in case the grid goes down. It’s a direct tradeoff:
- A higher reserve gives you more protection during an outage, but leaves less battery available for daily savings.
- A lower reserve means more battery capacity is used for daily savings, but you have less backup if the power goes out.
For most of LA, Ventura, and Orange County, starting with a reserve of 20% to 30% is reasonable. If you live in a PSPS (Public Safety Power Shutoff) or wildfire-prone area, where long outages are possible, a higher reserve is worth the extra safety. Only you can decide how much an outage would affect you.
A common mistake is setting the reserve near zero to maximize savings, only to be unprepared during the first PSPS event of the fire season. Check your area’s outage history before choosing a very low reserve.
Virtual Power Plants (VPP): worth it, or not?
If you want to get paid for exporting energy, a Virtual Power Plant is the best passive return available — better per kWh than chasing the daily NBT export rate. Just don’t expect it to transform your bill. Here’s the honest picture, and then the case for and against.
In a VPP, Tesla and SCE pay you to let your Powerwall discharge to the grid during a handful of high-demand grid events. For the Tesla VPP with Southern California Edison, here’s how the program actually works today:
- Season: Events only happen between May 1 and October 31 — the high-demand summer/fall months.
- Window: Events fall between 4 p.m. and 9 p.m. (the same peak window we’ve been talking about all along) and last from 1 to 5 hours.
- Cap: Up to 60 hours of events per year.
- You stay in control: You can set a separate backup reserve just for VPP events, so you don’t have to compromise your everyday outage protection — and you can opt out of any individual event if you’d rather keep the charge that day.
What it actually pays
This is where most write-ups get vague or overhype it, so let’s be straight. Tesla’s in-app estimate for one real SCE system came out to roughly $224 for the year — about $32 per event across 7 events. Your number will differ based on your system size and your backup reserve settings, and actual compensation varies event to event.
So: a couple of hundred dollars a year, not a windfall. Whether that’s worth it comes down to one question: how much do you value uninterrupted control over your own battery?
The case for enrolling: It’s close to free money. You’re getting paid for energy during summer evenings when you’d often be exporting at low NBT value anyway. You keep your outage protection through a separate VPP backup reserve, and you can opt out of any individual event. If your battery would otherwise sit near full all summer doing nothing during those hours, there’s little reason not to collect the check.
The case for skipping it: A few hundred dollars a year may simply not clear your bar for letting the grid lean on your battery — even on a limited, opt-out basis. If you live in a PSPS or wildfire-prone area and value having every kWh under your own control heading into a summer evening, “no thanks” is a completely rational answer. The money is real but modest; resilience and control have value too, and only you can price that.
There’s no universally right call here. Set your expectations to the true number — not the hype — and decide based on what you actually care about. You can enroll, try it for a season, and leave anytime if it doesn’t sit right.
Check your eligibility in the Tesla app under the Virtual Power Plant section, and review the program facts before you enroll.
A note for LADWP customers
Everything above assumes you’re an SCE customer on NBT. If you’re in LADWP territory, the rules are different. LADWP is a municipal utility and does not use the Net Billing Tariff. Its net metering and export structures differ, so the export-setting logic changes completely. To get up-to-date and accurate advice, LADWP customers should refer to the official LADWP solar webpage, contact LADWP customer service directly, or talk with a local solar installer experienced with LADWP systems. Checking your most recent LADWP bill or program page can help you find the net metering program details specific to your situation.
If you’re an LADWP customer, don’t use NBT-based advice for your system. The mode and reserve tips still mostly apply, but the export economics are different. Check your specific program before making changes.
Common mistakes we see
- Never verify the rate plan in the app. The default may not match your actual SCE schedule. Check it.
- Assuming “Everything” always maximizes savings. Under NBT, it often doesn’t outside the summer evening windows.
- Setting backup reserve too low in the fire/PSPS country. Savings don’t matter much when you’re sitting in the dark.
- Leaving the installer’s settings and never checking them again. As your usage and seasons change, it’s worth spending 15 minutes twice a year to review your settings.
- Skipping VPP enrollment. It’s the best export return available, and most people don’t know it exists.
When to bring in your installer
If you’ve checked everything above and still aren’t sure whether Time-Based Control or Self-Powered saves you more, it’s time to talk with your installer. Don’t just ask what most people use; focus on your actual numbers. If your installer can’t answer your questions or help, your next step is to contact Tesla support directly through the app, website, or customer service line. You can also look for advice in local Powerwall owner groups and online forums, where other homeowners may have experience with similar setups and settings. Here are the questions to ask:
- What’s the exact TOU-D plan I’m on, and is it set correctly in the app?
- Given my system size and my real evening load, which mode comes out ahead, and why?
- Am I eligible for a VPP, and what does it pay?
A good installer can answer all four questions based on your situation. If they can’t, that’s important to know as well.
How AWS Solar approaches this
We’ve been installing solar, battery storage, and electrical systems across Los Angeles and Ventura Counties since 2007, always under the same C-10 license, using our own crews and no subcontractors. When we finish a system, setting up these options and explaining why they’re chosen is part of our job, not an afterthought. Your settings should align with your rate plan, home, and priorities, and you should understand the reasons well enough to adjust them yourself.
This guide is for general educational purposes and explains how time-of-use rates and the Net Billing Tariff work for SCE residential customers as of mid-2026. It is not financial or tax advice. Your actual savings depend on your rate plan, system size, usage, and interconnection date. Utility tariffs and program details can change, so check the latest information with SCE and your installer before making decisions.