TOU Battery Savings
Flip one setting. Save through September.
From June 1 through September 30, Georgia Power's on-peak rate is roughly 13× the overnight rate. If your battery is set to Savings / TOU Mode, it captures that spread automatically every weekday from 2 to 7 PM. If it's still on Self-Consumption, you're leaving money on the table.
On-Peak
M–F · 2–7 PM · Jun–Sep
Off-Peak
All other summer hours
Super Off-Peak
Every day · 11 PM–7 AM
Enphase Battery Setup
- Open the Enphase app
- Tap your system → Battery
- Choose Savings (or "Cost Savings")
- Set peak: Mon–Fri 2:00–7:00 PM
- Confirm reserve SoC for grid outage
Franklin Battery Setup
- Open the Franklin Home Power app
- Tap Settings → Operation Mode
- Choose Time of Use
- Configure peak: Mon–Fri 2:00–7:00 PM, Jun–Sep
- Set super off-peak charging window if enabled
How the math works
Calculations, assumptions, and Georgia Power tariff references
Savings come from the rate spread between Georgia Power's on-peak window and the overnight super off-peak window on the Overnight Advantage plan (formerly Plug-In EV). When your battery is in TOU mode, it reserves capacity through the day and dispatches into the expensive 2–7 PM window — and where permitted by your interconnection agreement, charges from the grid overnight at the cheapest rate.
Assumptions: one full peak-window dispatch per day, 90% round-trip efficiency (typical for Enphase IQ and Franklin aPower LFP chemistry), 87 weekday peak days from June 1 through September 30, 2026 (excludes Labor Day; July 4 falls on a Saturday this year).
What this doesn't include: the value of any solar production stored in the battery and dispatched at peak (additional upside), demand-charge avoidance (not applicable to residential Overnight Advantage), or backup-power value during outages. If your interconnection agreement prohibits grid-charging the battery, your savings come from solar-stored discharge against the peak rate — still substantial, roughly $0.20/kWh per peak day instead of $0.27.
*September shows 21 peak days after excluding Labor Day (Sep 7). Rates shown are base energy rates from the Overnight Advantage schedule and exclude riders, fuel cost recovery, and franchise fees, which apply equally regardless of dispatch timing and therefore don't affect the savings calculation.
- TOU-OA-14 · Time of Use – Overnight Advantage tariff (PDF) The schedule this calculator is built around. Defines on-peak, off-peak, and super off-peak windows and base energy rates.
- TOU-FCR-6 · Time of Use Fuel Cost Recovery schedule (PDF) Fuel cost adder applied to all TOU-OA kWh consumption (currently ~4.5¢/kWh). Applies equally to all dispatch timing.
- Overnight Advantage rate plan · Georgia Power Customer-facing overview, enrollment, and current pricing summary.
Turn this estimate into a real proposal.
We model your building load, solar production, carbon offsets, and financing options — and confirm the safe-harbor deposit needed before July 4, 2026 to lock in the 40% ITC.