Octopus Flux is an import and export electricity tariff designed for households with solar panels and a home battery. It works by charging your battery from cheap overnight grid electricity, letting your solar panels power the home during the day, and then paying you a premium export rate when you sell surplus energy back to the grid during the evening peak.
For EV owners with solar and a battery, Flux adds another layer: the cheap overnight import window (2am–5am) is also the slot when you charge your EV from the grid at the lowest available rate.
An average solar household with a 4.9kWp installation and 5.2kWh battery saves approximately £937 per year on Octopus Flux, combining reduced import costs with premium export revenue.
What Is Octopus Flux?
Octopus Flux is a three-rate electricity tariff with separate import and export prices across three daily time bands:
- Off-peak (2am–5am): Cheap import rate — charge your battery and EV from the grid
- Standard (5am–4pm and 7pm–2am): Mid-rate import and export — normal daily usage and solar generation
- Peak (4pm–7pm): High export rate — sell your battery’s stored energy back to the grid at premium price
The tariff is designed so that energy flows in a deliberate daily cycle: grid energy in overnight, solar in during the day, stored energy out during the evening peak. Households that run this cycle consistently extract maximum value from both their solar investment and the tariff structure.
Rates vary by region. As an example, in London (April 2026):
- Off-peak import: approximately 15.89p/kWh
- Peak import: approximately 37.07p/kWh
- Peak export: approximately 28.6p/kWh
- Off-peak export: approximately 5.24p/kWh
These rates change periodically. Always verify current rates at octopus.energy.
Requirements for Octopus Flux
To qualify for Octopus Flux, you need:
- Solar panels — any brand, any size installation
- A home battery — any brand (Tesla Powerwall, GivEnergy, Fox ESS, Solaredge, Huawei, and others are all compatible)
- Both installed by an MCS or Flexi-Orb certified installer
- A compatible smart meter — SMETS2 or a Secure SMETS1 meter
An EV is not a requirement for Flux, but the cheap overnight import window makes it particularly valuable for households that also want to charge a car cheaply.
How Flux Works for EV Owners
Charging your EV overnight on Flux
During the off-peak window (2am–5am), you can charge both your home battery and your EV from the grid at the cheaper overnight import rate. You set a charging timer on your EV or charger app to start charging at 2am and complete before 5am, or use a compatible smart charger to schedule it automatically.
The three-hour window is shorter than the overnight windows on standard EV tariffs (Octopus Intelligent Go runs 11:30pm–5:30am; EDF GoElectric runs 11pm–6am). For most daily commuters who need a partial top-up, three hours at 7kW adds approximately 21kWh — around 65–75 miles of range — which covers the average UK daily commute several times over.
Drivers who need a larger overnight charge may also use part of the standard-rate period (which begins at 5am) at the standard import rate, which is still typically lower than peak-period pricing.
Solar generation during the day
Your solar panels generate electricity during daylight hours. Any surplus generation that your household does not consume can be exported at the standard export rate, or stored in your home battery for use during the peak period.
With Flux, the goal is to maximise the energy stored in the battery by solar before the 4pm peak window opens.
Exporting during the evening peak
Between 4pm and 7pm, the export rate reaches its daily high. Households discharge their home battery into the grid during this window, receiving the premium export rate in return. This daily arbitrage cycle — cheap overnight import, solar generation during the day, premium evening export — is what makes Flux financially compelling for solar + battery owners.
The Flux cycle for EV owners
If you have an EV, solar, and a battery, the daily Flux cycle looks like this:
- 2am–5am: Charge home battery and EV from the grid at the cheap import rate
- 5am–4pm: Solar panels power the home and (during peak generation) the EV if still plugged in; any surplus charges the battery
- 4pm–7pm: Discharge the home battery to the grid at the premium export rate; EV should be charged and disconnected by this point
- 7pm–2am: Normal standard-rate household consumption
The combination of cheap overnight imports, zero-cost daytime solar, and premium evening exports can make Flux dramatically cheaper than any standard domestic tariff.
Octopus Flux vs Intelligent Octopus Flux
Octopus offers two Flux variants:
Octopus Flux is the standard version. It provides the three-rate structure described above. You manage battery charging and EV scheduling yourself via timers and apps.
Intelligent Octopus Flux is the automated version. Octopus integrates directly with compatible battery systems and, for some EVs, with the vehicle directly. The system optimises charge and discharge cycles automatically based on forecast solar generation, grid prices, and your preferences. Intelligent Flux currently works with a more limited range of battery brands than standard Flux. Check compatibility at octopus.energy.
For most households, standard Flux delivers the core benefit. Intelligent Flux adds hands-off automation if your battery brand is supported.
Octopus Flux vs Octopus Intelligent Go for EV Owners
If you have solar and a battery, Flux is designed specifically for your situation. The three-rate structure maximises the value of both your hardware and your EV charging.
If you do not have a battery, Flux is not available to you (a battery is a prerequisite). In that case, Octopus Intelligent Go offers a simple 8p/kWh overnight rate with automated EV scheduling, and may work alongside a solar export tariff such as Octopus Outgoing.
For a full comparison of all EV tariff options, including those for solar households without batteries, see our EV smart tariff guide.
Which Home Chargers Work Well with Octopus Flux?
Any smart charger that allows you to set a charging schedule — a start time and an end time — works with Octopus Flux. You need the charger to start within the 2am–5am window and complete charging before 5am (or accept a partial charge from the standard-rate period).
Zappi (myenergi) is particularly well-suited to Flux households. It integrates with solar generation, prioritising solar input when available and delaying grid charging to the off-peak window automatically. The Zappi’s Solar Boost and ECO modes align well with Flux’s daytime solar profile.
Hypervolt Home 3 Pro supports scheduled charging and works alongside Flux’s overnight window via timer-based scheduling.
Ohme Home Pro can integrate with tariff pricing and offers smart scheduling compatible with Flux’s overnight import window.
Is Octopus Flux Worth It?
For households with solar and a home battery who are already paying a standard tariff or a basic export rate, Flux typically offers a significant upgrade.
The estimated £937 annual saving for an average solar household (4.9kWp, 5.2kWh battery, 3,400kWh annual consumption) assumes consistent use of the overnight import window and regular export during the evening peak. Households with larger batteries, more solar capacity, or higher energy consumption tend to see proportionally greater savings.
Households with very small batteries (under 5kWh) may find the export revenue modest, but still benefit from cheap overnight imports for the home and EV.
The tariff is most effective when:
- You adjust battery charge settings to fill from the grid during the 2am–5am window
- Your solar panels generate enough daytime surplus to approach a full battery by 4pm
- You are willing to adjust high-consumption habits (EV charging, heavy appliances) to overnight and solar periods
Frequently Asked Questions
Can I join Octopus Flux if I have an EV but no battery? No. Octopus Flux requires both solar panels and a home battery. If you have solar but no battery, Octopus Outgoing (a simple export tariff) combined with Octopus Intelligent Go for EV charging is a practical alternative.
What is the off-peak import rate on Octopus Flux? Rates vary by region and change periodically. In London (April 2026), the off-peak import rate is approximately 15.89p/kWh. This is higher than the overnight rate on Octopus Intelligent Go (8p/kWh), but Flux users offset this through premium export revenue (approximately 28.6p/kWh during the peak window). Verify current regional rates at octopus.energy.
How long is the cheap import window on Octopus Flux? The off-peak import window runs from 2am to 5am — a three-hour window. This is shorter than most standard EV tariffs. Charging a 7kW home charger for three hours adds approximately 21kWh, which is sufficient for most daily commute top-ups.
Does Octopus Flux work with all home batteries? Standard Flux works with all solar and battery combinations installed by an MCS or Flexi-Orb certified installer. Intelligent Flux (the automated variant) has a more limited battery compatibility list — check octopus.energy for the current list.
Is Octopus Flux still available to new customers? As of our last research update (April 2026), Octopus Flux is available to eligible customers with qualifying solar and battery installations. Availability can change — verify directly with Octopus before making investment decisions based on tariff access.
Key Takeaways
- Octopus Flux is a three-rate import/export tariff for solar + battery households, with cheap overnight import (2am–5am), standard daytime rates, and premium evening export (4pm–7pm).
- EV owners on Flux charge their car during the overnight off-peak window alongside the home battery, adding approximately 21kWh (65–75 miles) in three hours on a 7kW charger.
- An average solar household (4.9kWp, 5.2kWh battery) saves approximately £937 per year on Octopus Flux by combining reduced import costs with premium export revenue.
- You need solar panels and a home battery installed by an MCS or Flexi-Orb certified installer to qualify.
- The Zappi charger is particularly well-suited to Flux households due to its solar-prioritisation modes.
Useful Resources
Octopus Energy — Flux tariff
https://octopus.energy/smart/flux/
sunsave.energy — Octopus Flux review (April 2026)
https://www.sunsave.energy/solar-panels-advice/exporting-to-the-grid/octopus-flux
Energy Saving Trust — Smart charging for EVs
https://energysavingtrust.org.uk/advice/smart-charging-electric-vehicles/