Short answer: it depends entirely on one thing — do you have a battery (or some way to shift your usage)? Without one, Rate 8 usually wins and switching to Rate 7 can quietly cost you money. With a battery sized to cover the peak, Rate 7 wins by a wide margin. Most comparisons skip that fork in the road, so here's the honest version from someone running Rate 7 at his own house in Charleston.
The one-line difference
Rate 8 is Dominion's standard residential plan and what most South Carolina homes are on by default. It charges for energy by how much you use, not when — the time of day doesn't change the price.
Rate 7 is a time-of-use demand plan. Energy is cheap most of the day and overnight, expensive during a short on-peak window, and on top of that it adds a demand charge tied to your highest burst of on-peak usage. It rewards you for moving load off the peak — and penalizes you if you can't.
That demand charge is the whole game, and it's why the comparison isn't as simple as "TOU is cheaper."
Rate 7 without a battery often loses to Rate 8
This surprises people. If you switch to Rate 7 but keep living the same way — running AC, cooking, and laundry through the late-afternoon peak — you now pay the expensive on-peak energy rate and trigger the demand charge, with nothing offsetting either. For a typical household, that combination can land higher than just staying on flat-rate Rate 8.
So the move that looks like "switch to the cheaper plan" is only cheaper if you actually change your usage pattern. Doing it by hand — cutting AC and appliances every weekday afternoon — is possible but miserable, and one forgetful day undoes the savings. That's the problem a battery solves automatically.
With a battery, Rate 7 flips and wins
Here's where it pays off. You charge the battery overnight when power is cheapest, then run the house off stored energy during the expensive window — so you buy almost nothing at the on-peak rate and keep your on-peak demand low.
My own setup proves the gap. In June my house used 1,846 kWh. Priced on Rate 7 with the battery covering the peak, my electricity charges came to about $190. That identical 1,846 kWh on standard Rate 8 would have been about $311 — roughly $120 more for the exact same usage in the exact same house. The battery didn't create energy; it just moved my usage onto the cheap side of the rate and kept my peak demand down.
That's the real answer to "is a battery worth it" — and I break the full math down in is a home battery worth it on Dominion Rate 7.
Which rate is right for you
- Stay on Rate 8 if you have no battery and no realistic way to keep your weekday late-afternoon usage low. The flat structure protects you from the demand charge you'd otherwise eat.
- Move to Rate 7 if you have a battery sized to cover your peak — or you're seriously considering one. That's when the cheap overnight charging and low on-peak demand turn into real monthly savings.
The deciding factor is almost never the rate by itself. It's whether you can keep your on-peak demand low every day it applies. If you can, Rate 7 wins. If you can't, it doesn't. Understanding how Rate 7's demand charge actually works is what makes the difference make sense.
One more thing worth knowing: Dominion has proposed time-of-use changes that, if approved, take effect July 1, 2026 and would shift the rate periods and treat weekends and holidays like weekdays. I cover what's changing in Dominion's 2026 time-of-use rate changes — verify the current periods before you switch.