Best Powerwall settings for SCE TOU-D-PRIME
TOU-D-PRIME in plain English: SCE’s time-of-use rate for electrified homes — an EV, battery, or heat pump qualifies you.
PRIME rewards electrified homes with cheap daytime and overnight power — and punishes the 4–9 PM window every day of the year: 61¢ on summer weekdays, 45¢ all winter. Your battery’s whole job is to make evenings look like midday.
The plan at a glance
| Season | Period | Hours | Rate |
|---|---|---|---|
| Winter Oct 1 – May 31 | Mid-peak | 4:00–9:00 PM, every day | $0.45/kWh |
| Super off-peak | 8:00 AM–4:00 PM, every day | $0.24/kWh | |
| Off-peak | 9:00 PM–8:00 AM, every day | $0.30/kWh | |
| Summer Jun 1 – Sep 30 | On-peak | 4:00–9:00 PM, weekdays | $0.61/kWh |
| Mid-peak | 4:00–9:00 PM, weekends | $0.39/kWh | |
| Off-peak | All other hours | $0.26/kWh |
What changed for winter 2026–27 (from October 1, 2026): winter overnight (9 PM–8 AM) is no longer priced like midday — it is 30¢ against 24¢ for 8 AM–4 PM — and the evening 4–9 PM rate is 45¢, down from the 56¢ this guide listed in July. That shrinks the overnight-to-evening spread to 15¢ and makes the middle of the day the cheapest grid power of the winter. Also on this plan: a $0.79/day base charge, no baseline credit, and 4–9 PM is the most expensive window all year. Rates are SCE’s published TOU-D-PRIME prices for bundled customers as of October 2026 — always verify current numbers with your utility, and update the rate plan in the Tesla app too, since Savings mode (formerly Time-Based Control) only sees the prices you give it.
What this plan means for a Powerwall
The play is the same shape as PG&E’s EV plans: store cheap or solar energy, spend it 4–9 PM, and let the house ride through the peak without buying. The size of the prize moves with the season. In winter the spread is 21¢ against midday power (45 vs 24) and 15¢ against overnight (45 vs 30); on a summer weekday it is 35¢ (61 vs 26), and on a summer weekend only 13¢. Ten kWh shifted into every evening is on the order of $55–60/month in winter and $75–80 in summer of avoided peak cost after battery losses.
Charge the battery in the middle of the day, not overnight, in winter. With super off-peak at 24¢ from 8 AM to 4 PM, the cheapest time to top up from the grid on a cloudy week is now midday — and it sits right under your solar. Overnight grid charging still beats buying at 4–9 PM, but it costs 6¢ more per kWh than it needs to. The same logic applies to an EV: if you can plug in between 8 AM and 4 PM, do; if you have to charge overnight, keep it there rather than running it off the Powerwall — a 6¢ gap is not worth a battery cycle.
What changes the details is your export scheme. On NEM 2.0, exports still earn near retail — surplus solar is fine going to the grid. On the Net Billing Tariff (post-2023 solar), exports earn a fraction of retail, so the priority flips hard toward self-consumption: fill the battery first, run the house second, and export only what’s left. SolDial reads which scheme you’re on and values every kWh accordingly.
Settings: Savings mode, reserve 20–35%, grid charging on for cloudy-week resilience (with the three winter price levels entered in the Tesla app so it charges at 24¢, not 30¢) — and on NBT, make sure your battery isn’t exporting stored energy for pennies.
The automations worth having
Pre-peak top-up on solar; a hold that keeps the pack from draining before 4 PM; EV charging steered to super off-peak in winter (8 AM–4 PM) and kept out of 4–9 PM all year; storm watch override; and — on NBT — an export posture that ships only true surplus.
Does this apply to my exact situation?
Plans vary by zone, season, and enrollment vintage, and utilities revise rates. SolDial matches your account to the actual published schedule from ~50,000 tariffs and recomputes the strategy — and the honest savings math — from your windows, not a blog’s snapshot. If your plan differs from this page, the app follows your plan.