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Flux tariff for solar and battery storage

Octopus Flux is the pioneering electricity tariff in the UK that offers import and export rates in a single package. It answers a call for a tariff specially designed for homes with solar panels and home battery storage. This innovative time-of-use tariff enables customers to take control of their home energy needs, allowing for greater flexibility in managing their energy consumption.  (Battery storage isn’t a necessity but it helps!)

If you own solar panels and battery storage Octopus Flux is a plug-and-play tariff which combines import and export rates in one tariff. All you need to do is set the import and export times and ensure you make the most of cheap import rates to fill your battery and peak export times to get the most for your excess solar generation.

The benefits of Octopus Flux;

  • An attractive rate for exporting excess energy during peak times between 16.00 and 19.00.
  • Off-peak period for charging batteries when demand on the National Grid is traditionally lower between 02.00 and 05.00.

If you are passionate about green technology and are looking for an electricity tariff for solar and battery storage that will help you maximise your return take a look at Octopus Flux. It is a very attractive tariff, particularly during the spring and summer when the days are longer and there is more potential for exporting excess solar generation.

Octopus Flux Review 2024.

There are many variables to consider when finding the best energy tariffs to help reduce your home energy bills.  If you have invested in Solar PV and battery storage you will be keen to ensure you get the best rates possible especially for importing during an off-peak window to charge your battery and exporting when you can make the biggest return.

Having recently installed solar panels and battery storage, I have become slightly obsessed with constantly reading about export tariffs to ensure I am on the best rate to export excess energy. Thankfully, Octopus recognises the requirements of environmentally conscious customers and offers a range of tariffs tailored to your specific usage and consumption of home-generated power.

Octopus Flux offers a comprehensive package for customers interested in solar and battery storage solutions. While it is a great option, there are other tariffs available that may better suit your specific home energy requirements and preferences. It is important to consider all options before deciding to ensure maximum savings on your bills. 

To make Octopus Flux work for you, you’ll need to export more than you import during the peak period between 16.00 and 19.00 each day.

I WILL BE UPDATING THIS BLOG POST IN THE BEXT FEW DAYS AS THE TARIFF IS LESS ATTRACTIVE POST 1ST APRIL PRICE CHANGES.

How does Octopus Flux work?

Octopus Flux has 3 rate periods and one standing charge covering import and export, making it unique.

Octopus Flux isn’t a fixed tariff the rates will change when the Energy Price Cap is reviewed. The next price change will happen on the 1st of July 2024.

  1. Super cheap rates between 02:00 – 05:00 every day, when you can top up your battery with any extra energy you may need.
  2. A peak rate between 16:00 – 19:00, is the optimum time to discharge your battery and export surplus energy back to the grid.
  3. A flat day rate that covers all other times.

Rates will vary slightly throughout the country. You can get a quote by inputting your postcode.

You could also consider Octopus Agile, Cosy tariff and Octopus Economy 7. If you have an EV also look at Octopus Intelligent and Go.

What are the import and export rates on Octopus Flux?

These are the rates on Octopus Flux for South Wales, they may vary slightly geographically. They will also change on the 1st of July 2024 as the rates are flexible and follow the Energy Price Cap.

You could switch to Octopus Flux as a set-and-forget tariff for your home battery and solar export needs. It would work year-round if you programmed your battery and home smart devices to come on during the off-peak period. However, if you are happy to split your tariffs into summer and winter you could find over the year you’d make a bigger saving on your energy bill.

Third-party sites like Octopus Compare can help run some numbers but I think there’s a small app fee to use all the features.

Are 3 hours off-peak enough to charge a home battery?

The off-peak window on Octopus Flux is between 02.00 and 05.00 each day. If your charge rate is at least a third of the battery size you’ll be able to fully charge your home battery during the Octopus Flux off-peak period.

As an example, all of these batteries can be fully charged in 3 hours;

  • GivEnergy 9.5 kWh battery has a charge rate of 3.6 kW. (9.5 kWh % 3.6 kW = 2.6)
  • GivEnergy All-In-One 13.5 kWh battery has a charge rate of up to 6 kW. (13.5 kWh % 6 kW = 2.25)
  • Tesla Power Wall 13 kWh battery has a charge rate of 5 kW. (13 kWh % 5 = 2.6)

Charging your home battery will be a priority during the winter months when there is less sunshine and all of these batteries can be fully charged during the Octopus Flux off-peak period.

Octopus Flux tariff as a seasonal tariff.

  • For 18 hours hour of the day, the lowest price you will get for exporting your excess electricity is currently 15.08p per kWh.  This is higher than the Octopus Outgoing fixed rate of 15p per kWh but there isn’t much in it Octopus Outgoing Fixed and the Octopus Cosy export day rate.
  • The peak rate is higher for import but you should be able to avoid this in the spring and summer and you’ll get 24.93p per kWh exporting between 4 pm and 7 pm.

So for those without battery storage (it is not a necessity on Octopus Flux) as the days get longer this is quite attractive especially if you don’t have an Electric Vehicle to fill up or lots of home devices to run to absorb this excess energy and you can you know you’ll be exporting at peak times.

This EU sunshine database is a quick way of reviewing how output might change throughout the year. It is quite handy if you have a new solar PV system and are not sure.  I have attached an example below, it shows data based on solar PV in Cardiff.

Octopus Flux tariff

My consideration this summer for exporting my excess solar generation.

This will be my first summer with solar panels and battery storage and I am considering switching to Octopus Flux tariff just for the summer. The issue is I have an EV and I am home all day with children. The home usage won’t be an issue in the summer but the EV charging may be but it will depend on my mileage which is historically higher in the spring and summer months.

Octopus Agile is also on my radar for both import and export (read my review on Octopus Agile) but this may suit me more than Octopus Flux as I am happy to be more hands-on monitoring prices and the best times to export each day.

Now that Octopus has reduced the prices of the exports rates on 1st April 2024 I don’t know if Octopus Flux will continue to be as attractive as it was last summer. My guess is Octopus Agile will prove more attractive for several customers.

In the winter Octopus Intelligent Go wins hands down for me though because of the cheaper EV charging which can also be used to fill my home battery.

When is the best time to be on Octopus Flux?

Octopus Flux is a good option from April to mid-October when the days are longer and there is more sunlight.

You can usually get better off-peak rates for importing energy on Octopus Agile but these rates are quite unpredictable and require a more hands-on approach each day. However, depending on your home set-up home and energy needs in the spring and summer this isn’t so much of an issue.  You will probably have enough solar generation to power your home, fill your battery and export to the National Grid during these lighter months regardless of your import tariff.

When days longer days;

  • You will be less reliant on importing energy.
  • Your focus will be on earning the most for your excess solar generation.

Benefits of Octopus Flux;

  • The peak export rate is the same time every day of the week. 
  • You can program your home battery to export over the spring and summer at the same time each day.
  • Between 4 pm and 7 pm, it will still be daylight hours so timed export at peak times from your battery shouldn’t be too much of a problem. (From spring to early autumn.) You’ll still probably be getting some power from the sun.

Bring me sunshine and longer days!

This diagram should help you better understand the concept. This is my interpretation of the Octopus Flux Tariff and not an official image from the Octopus Energy website.

In the summer, the yellow solar line will extend further, providing you with a greater chance to export energy at the peak rate while keeping your battery charged with green electrons. 

Remember there are no exit fees with Octopus Flux or any Octopus tariffs so having seasonal tariffs may make sense.

Octopus Flux

In the summer, the yellow solar line will extend further, providing you with a greater chance to export energy at the peak rate while keeping your battery charged with green electrons.

During darker months it’s worth looking at other Octopus tariffs.

Am I eligible to switch to the Octopus Flux tariff?

To switch to Octopus Flux you will need to be an Octopus customer and have solar PV.  The solar panels don’t need to be installed by Octopus although they can do that too!

You’ll need to have:

  • A smart meter which provides Octopus with half-hourly readings.
  • A copy of the MCS document for your solar system.
  • Confirmation your local energy network was notified of your installation. *

* This will be a letter or email you got from your energy network after they were notified by your solar installer.

There is no longer a limit on the invertor. At launch, the AC was limited to 9kW. This limit has now been removed.

If you receive Feed-in-Tariff payments from Octopus or another supplier, they’ll also need a copy of your (Microgeneration Certificate Scheme) MCS certificate.

@sarah_go_green Get paid for excess solar with the @Octopus Energy flux tariff. #octopusflux #octopusfluxtariff #fluxtariff #solarpanels #smarttariffs ♬ Here Comes the Sun – Relaxing Instrumental Music

You can export as much excess solar as you want there is no restriction and you can own an electric vehicle and charge that on the Octopus Flux tariff too.

Why do I need an MCS certificate to switch to Octopus Flux?

The Microgeneration Certification Scheme (MCS) is a standards organisation. They certify low-carbon energy technologies and contractors – including heat pumps, solar, biomass, wind and battery storage. MCS is considered a mark of quality in the industry.

An MCS certificate is not a mandatory or legal requirement for system installation BUT Octopus have have decided to make it a part of its terms in all of their Octopus export tariffs.


If you want a copy of your MCS certificate or you want to check if one has been registered for your property you can contact MCS at 0333 103 8130, or email: hello@mcscertified.com. You can also check if an installer is listed as MCS certified.

You will need to show Octopus your MCS certificate if you want to be paid for exporting your excess electricity.

When Octopus receives your MCS certificate they will apply to the Distribution Network Operator (DNO) for an export Meter Point Administration Number (MPAN ) for your smart meter. Once the MPAN is registered by the DNO Octopus can then start paying you for your exported electricity. If you export without this you won’t get paid and Octopus will not backdate any payments.

Can I get paid for my solar export without an MCS Certificate?

Octopus Energy is launching a trial where no MCS Certificate is required for solar export but this is separate from this tariff where an MCS Certificate is still required.

I double-checked with Octopus on Twitter and here is their response.

How do I switch to the Octopus Flux tariff?

The Octopus Flux tariff is now live. ☀️🪫

If you are an existing customer switch to Octopus by completing the online form and Octopus will take care of the rest.

New customers wishing to switch to Octopus Energy on the standard Octopus Flexible tariff first but as soon as your account is live and the switch has been completed you can ask to move to the Octopus Flux tariff.

As a new customer if you try to complete the Flux online form it will just direct you to the standard sign-up page. By using the linked page below to sign up you’ll get £50 credit after your first direct debit payment.  (I’ll also get £50 so a big thank you if you use my link)

Contacting Octopus Energy

If you are super keen once you have signed up as a new customer email hello@octopus.energy or DM Octopus on Twitter quoting your account number and ask to be moved to the Octopus Flux tariff as soon as possible as the switch is complete.  You can also phone them on 0808 164 1088.

My preferred method is to contact Octopus via Twitter they are really quick to reply but if you choose to call Octopus after signing up you can even select your on-hold music from your Octopus dashboard. They think of everything! Just ask if once your switch is complete they can automatically transfer you onto the tracker tariff. I’ve switched tariffs lots of times via Twitter.

Can I still receive Feed in Tariff (FiT) payments if I switch to Octopus Flux?

Feed In Tariff (FiT) closed to new applications in March 2019. If you are on the FiT you either signed up for 20 or 25 years depending on when you signed up.

On FiT you will be receiving a payment for;

  1. Energy generated
  2. Energy exported.

If you switch to Octopus Flux you can still receive FiT payments for energy generated but not energy exported. Octopus can cancel your FiT export payment if it’s registered with them. Alternatively, they will tell you when to contact the supplier your FiT is registered with to cancel it. Octopus Flux will then take over as your export tariff.

Once you cancel FiT export there is no going back. If you decide Octopus Flux isn’t for you you’ll need to claim the Smart Energy Guarantee (SEG) or another export tariff of your choice in order to be paid for your excess solar.

Just remember that deemed export is 50% of your generated energy. It doesn’t matter if you use all your solar and have nothing to export you still get the 50% payment on FiT. This is a good deal so you need to get your calculator out to see if you can beat it on Octopus Flux.  Deemed export is currently paid at the rate of 7.5p per kWh on FiT.

Octopus Flux tariff v Cosy Octopus tariff.

If you are one of the green pioneers who has lots of green solutions for your home, such as a heat pump, solar PV and battery storage Octopus Energy will have a tariff to meet your needs. There have been two new smart tariffs launched so far in late December 2022 and February 2023, Octopus Cosy and Octopus Flux. Finding which one suits your needs will take a little consideration as everyone’s home needs are different.

Octopus Intelligent Tariff v Octopus Flux when you own an Electric Vehicle. 

Octopus Flux is not designed for EV owners. If you have an Electric Vehicle Octopus has two dedicated tariffs just for you, they are Octopus Go and Intelligent Octopus tariffs. That being said if you have excess solar you could benefit from much higher export rates on the Octopus Flux tariff.

  • Intelligent Octopus Go export rates – You can choose any export tariff. Octopus Outgoing fixed, as an example, is 15p per kWh.
  • Octopus Go – You are limited to Octopus Outgoing Lite which is 8p per kWh for export.

You can read a full review of Octopus Export tariffs in my recent review.

If you own an EV, solar PV and battery storage here are some quick questions you could ask yourself if you want to stick your figure in the air to see if Octopus Flux is right for you.

  1. How many miles do you drive a week? A low mileage could be a good indication that Flux may well be worth a shot, especially from March to October.
  2. Could you charge your EV from solar during the day if you have a slightly higher mileage?
  3. What does your export/import balance look like? Do you regularly need to top up large amounts from the grid? You may find in the summer you have vastly different answers. Don’t be scared to have a spring/summer tariff and a winter tariff. It’s easy to switch between the two!
  4. How much control do you have over your battery? The daytime export rates on Flux are already good, but that peak rate is extra juicy! Being able to schedule a forced discharge and export in the peak means being paid even more for your solar by time-shifting it. Just remember the days are longer in spring/summer so you may be automatically exporting in any event as your batteries are full.
  5.  Are you happy to just have a go? – You are not locked into tariffs with Octopus, so if it doesn’t add up for you switch to another tariff.  If you switch away from say, Intelligent Octopus to Octopus Flux you’ll have to wait 30 days to switch back to that tariff but you can always choose another smart tariff or even a regular standard tariff. (Although there are so many smart tariffs you’d find a better solution)

Finger in the air v spreadsheets – Octopus Flux Tariff.

The finger-in-the-air approach may appeal to you if you want a quick general idea of Octopus Flux would be best for you. I get lots of questions about the viability of Octopus Flux if you own an EV but the answer depends on your circumstances. There are serval spreadsheet enthusiasts out there who share their figures and even let you input yours. You’d get a definite answer one way or another that way but spreadsheets make me come out in a cold sweat. 😀 If you want figures you could also look at the Octopus Compare app which I understand also includes a Flux comparison.

Tomorrow is another day and the sun will always come up!

Don’t worry if you’re unsure which Octopus tariff is right for you. There are plenty of options to choose from and you can easily switch between them at any point in your journey – there’s no need to make a permanent decision as there are currently no exit fees on any Octopus Energy tariffs.

Octopus Energy is pushing the boundaries of what customers can expect from their energy provider.  As an Octopus customer, you benefit from the company’s investment in technology and smart energy solutions, giving you more options than ever before!  The sun will always rise, and with it, new possibilities thanks to Octopus!

Read more on Octopus seasonal tariffs if you have a home battery.

You can read about alternative Octopus battery storage tariffs in my recent blog. This will prove helpful if you are looking for seasonal tariffs and don’t plan to stay on Octopus Flux all year.

Octopus Business Tariffs if you have solar panels.

If you have a business with solar panels added to your premises take a look at Octopus Panel Power Tariff. 

There is also a new time-of-use tariff for businesses called Octopus Shape Shifters which is a smart time-of-use tariff. (No solar PV required)