Octopus Flux Tariff

Unit Rates

Octopus Flux is a time-of-use import and export tariff designed for homes with solar panels and battery storage.

• off-peak (02:00–05:00): Cheapest import rates - ideal for charging your battery overnight.
• Peak (16:00–19:00): Highest import and export rates - best time to discharge and export energy.
• Day rate (all other times): Standard rate for typical household usage.

This structure allows users to buy electricity cheaply overnight and sell or avoid importing during peak hours, maximising savings and export revenue.

Overview

Octopus Flux is a UK tariff designed for households with solar panels and battery storage. It combines both import and export pricing into a single structure, rewarding users who shift energy usage and export to peak times.

How BatteryWiz optimises Octopus Flux

BatteryWiz automatically optimises your battery for the Flux tariff without requiring manual scheduling:

• The solver charges the battery during the 02:00–05:00 off-peak window
• The charge level is dynamically computed based on:
  • household load forecast
  • solar generation forecast
• During peak hours (16:00–19:00), BatteryWiz prioritises:
  • reducing grid import
  • exporting excess energy when beneficial

This removes the need for manual scheduling typically required by Flux tariffs.

Why optimisation matters

Octopus Flux requires users to manually align charging and discharging with tariff windows to maximise savings.

Without optimisation:

• Batteries may charge too much or too little overnight
• Solar energy may be underutilised
• Export opportunities during peak hours may be missed

BatteryWiz solves this by continuously recalculating the optimal plan based on real conditions.

Octopus Flux rate reference

These are the typical Flux import and export rates. Always verify your specific rates with Octopus Energy before signing up — rates are subject to change and Flux is paused for new sign-ups at the time of this write-up.

Window	Hours	Import (p/kWh)	Export (p/kWh)
Off-peak	02:00–05:00	15.49	5.05
Day rate	All other times	25.80	10.24
Peak	16:00–19:00	36.13	29.79

Worked example: a typical BatteryWiz Flux day

Assumptions: 10 kWh usable battery, 90% round-trip efficiency, 5 kWh charged overnight, 5 kWh discharged during peak.

• Overnight charge cost: 5 kWh × 15.49p = 77p
• Peak import avoided (4.5 kWh usable at 90% RTE × 36.13p): ~£1.63
• Net daily saving vs charging at the day rate: ~86p/day (before battery wear cost)

BatteryWiz recalculates this every 30 minutes using your actual solar forecast and load prediction — so on a sunnier day it will reduce overnight charging or skip it entirely.