Powering Tomorrow · UK
Pay night prices for daytime power.
OffPeak Energy is the UK's independent guide to home battery storage. Charge overnight for around 8p a unit, use it in the day instead of paying 28p, and cut £400–£900 off your electricity bill a year — solar not required.
Off-peak
0p
per kWh overnight (Intelligent Octopus Go, mid-2026)
Peak
0p
per kWh daytime import (UK average, 2026)
VAT
0%
on home batteries until 31 March 2027
Real payback maths
Every number on this site uses current 2026 UK rates — no glossy installer projections.
MCS-certified installers only
Quotes go to vetted MCS-registered installers with proper G99 approvals and warranties.
Solar optional
Yes, a battery still pays back without solar if you're on a smart tariff like Intelligent Octopus Go.
How it works
Charge cheap. Use it later.
Step 1
Charge overnight
A smart tariff drops import to roughly a third of the daytime rate for 5-7 hours. The battery fills up cheap.
Step 2
Power your day
You draw from the battery instead of the grid, avoiding the 28p peak rate for kettle, oven, wash cycles and EV top-ups.
Step 3
Track the payback
Our calculator models 15-year net position with degradation and cycles factored in — no brochure fluff.
The core tool
Will a battery actually pay back for your home?
Enter your annual usage and tariff. We'll compare importing at peak rates versus charging overnight, and show your annual saving, payback years and 15-year net position. Every assumption is visible and editable.
Open the calculator£640
Typical annual saving, 10 kWh battery
7-9 yrs
Typical payback on Economy 7 / smart tariff
13.5 kWh
Sweet-spot size for a 3-4 bed home
+10%
Extra savings if you already have solar
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