Dominion Energy South Carolina's July 2026 rate case (South Carolina Public Service Commission Order 2026-374) took effect with the first billing cycle of July 2026, and it reshaped the Rate 7 time-of-use plan. If you're on Rate 7 — or thinking about switching — the changes move the windows your whole strategy is built around. Here's the plain-English read, straight from the updated tariff.
What changed
Three things stand out for residential customers:
- On-peak now applies every day. This is the big one. Before, on-peak only ran Monday–Friday, with weekends and holidays off-peak. The updated tariff defines on-peak as simply the hours 4–8 p.m. in summer (May–Sep) and 6–9 a.m. in winter (Oct–Apr) — with no weekday or holiday exception. So the expensive window now hits every day, weekends included. (The clock times themselves didn't change — only which days they apply.)
- A new winter midday super-off-peak window. There's always been a super-off-peak band overnight (1–5 a.m.) year-round. July 2026 adds a second super-off-peak stretch in winter: 12–3 p.m., October through April. That's a bonus block of the cheapest power in the colder months — ideal for topping off a battery or running heavy loads.
- Rates went up across the board. On-peak is now $0.17441/kWh, off-peak $0.10124/kWh, and super-off-peak $0.08841/kWh, plus a $10.90/kW on-peak demand charge. The overall bill rose too — about 7.6% for a typical home, on standard and time-of-use plans alike; see Dominion's July 2026 rate increase. Rates climb most years — one more reason the math favors getting on the right plan sooner rather than later.
What it means if you have a battery
The every-day change makes a properly sized battery more valuable, not less. Before, if you pulled heavy load on a Saturday afternoon it didn't matter — weekends were off-peak. Now that protection is gone, and covering the window seven days a week is part of the job. A battery that already carries your house through the weekday peak just extends the same behavior to weekends automatically. Manual load-shifting, on the other hand, gets harder — there's no weekend break from watching the clock.
The new winter midday super-off-peak window is also good news for battery owners: another cheap stretch to charge in during the months when on-peak shifts to the morning.
What to do now
- If you're on Rate 7, update any schedules built around the old weekday-only window — thermostat setbacks, battery discharge windows, and EV charging timers now need to account for weekends too.
- If you're about to switch to Rate 7, here's how to switch to Rate 7.
- If you're sizing a battery, size it to cover the window comfortably — the every-day change means there's less slack for a system that can only just cover the peak. More in what size battery you need.
The bottom line
The expensive window now applies every day, and rates went up. That doesn't change the core strategy — charge cheap, cover the peak — it just raises the bar on doing it consistently, which is what a battery is for. If anything, it strengthens the case in is a home battery worth it on Dominion Rate 7.