Powerwall on Duke RETC: win the CPP days
RETC in plain English: Duke’s residential time-of-use rate whose real money is a handful of Critical Peak Pricing event days a year.
RETC’s everyday spread is respectable — but the plan’s real teeth are Critical Peak Pricing events, a handful of days when peak power costs multiples of normal. Those days are where a battery earns its keep.
The plan at a glance
| Period | Hours | Rate |
|---|---|---|
| Off-peak (winter) | Overnight & midday valleys | $0.075/kWh |
| Peak (winter) | Morning & evening ridges | $0.218/kWh |
| CPP events | Utility-called days | Multiples of normal peak |
Exports on the Bridge/NBT scheme earn ~4¢ — self-consumption dominates. Rates come from the published tariff as reflected in SolDial's rate database in mid-2026 — always verify current numbers with your utility.
What this plan means for a Powerwall
Two games run in parallel. The daily game: a ~14¢ winter spread worth shifting into every morning and evening ridge — modest but real, on the order of tens of dollars monthly. The event game: when Duke calls a CPP day, peak energy jumps to several times normal, and a full battery discharged through the event window can be worth more that single day than a week of routine shifting.
With exports earning only ~4¢, stored energy should never leave the house. Settings: Time-Based Control for the daily ridges; and on CPP notice, an override that fills the pack beforehand and rides the event on battery.
The automations worth having
CPP-event response (SolDial tracks your CPP rate and event dates); the daily pre-ridge holds; EV charging in the valleys; storm watch. The CPP override alone justifies automating this plan — it’s exactly the rare-but-expensive moment humans miss.
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.