Octopus Flux

Octopus Flux is an electricity tariff with varying import and export prices.

When used with a battery, it allows you to earn income by selling your electricity at peak times.

What is Octopus Flux?

Octopus Flux is a time-of-day (ToD) electricity tariff from award winning energy supplier Octopus Energy.  Instead of paying a flat rate for the electricity you purchase, the price varies by the time of day.  The tariff reflects the wider wholesale electricity market, so you pay more at peak times in the evening and less at night when demand is low.

The Octopus Flux Tariff is unique in that both the electricity import and the electricity export rate vary in this way.  With Octopus Energy Flux the import price for electricity in the middle of the night is actually lower than the price paid for export in the evening peak.  So if you have a battery, you can charge and discharge to take advantage of this, earning you money in the process!

That’s obviously good for your pocket, as it maximises the utilisation of your battery every day and improves the economics. However, it’s also good for the wider UK electricity system as we won’t need so many fossil-fueled power stations running at peak time.  And that’s good for the planet too – With the Octopus Flux tariff it really is a win/win.

Import prices vary with time of day

Export prices vary with time of day

Export prices in the evening are higher than import prices at night

  So you can earn extra income

Also works alongside solar

How does Octopus Flux work?

The Octopus Flux tariff is split into three price bands:

  • 02:00-05:00 Super cheap rates
  • 05:00-16:00 Standard rates
  • 16:00-19:00 Peak rate
  • 19:00-02:00 Standard rate again

The prices for this tariff do change, so check out the latest prices here.  We’ve shown graphically here – note how the export price is higher at peak than the import price during super-cheap rates.

Octopus Flux, pricing, tariff

In order to qualify for the Octopus Energy Flux tariff, you will need solar panels installed.  You will also need to be signed up to Octopus Energy Smart Export Guarantee (Octopus SEG) – that is to say that Octopus Energy are the designated authority for paying you for your exported electricity.

Octopus Flux and the Tesla Powerwall

The Octopus Energy Flux tariff works particularly well with the Tesla Powerwall, due to the smart algorithms it uses to control charging and discharging.  These combine weather forecasts at your location, with inputted Octopus Flux tariff prices, to determine the best charge/discharge regime for the battery over the day.

Compared to the conventional way of using a home battery, an  economically optimised way of operating your battery with Octopus Flux looks like this:

Starting at midday:

  • Solar energy production will power any loads in the home, with any excess filling up the battery.
  • By the time the peak electricity tariff starts at 16:00, the battery should be virtually full. Between 16:00 and 19:00, the battery discharges to the home, and also exports to the grid to take advantage of the high electricity export tariff.
  • The battery doesn’t fully discharge, however. Instead it leaves enough energy in the battery to run the home through the evening and early night until 02:00.  (It will also leave a reserve for power cut ride through.
  • At 02:00 the battery will charge from the grid at the super cheap night time rate. However, it won’t fully charge the battery.  Although super cheap electricity is great, it’s not as good as free electricity from your solar roof!  So, the Tesla Powerwall leaves space for tomorrow’s expected solar generation.  If it expects it to be sunny, it may not top up at all, to leave as much space as possible.  If it’s expected to be cloudy then it will top up more. This smart algorithm is based on weather forecast data in your location and it’s knowledge of your typical loads.

Talk to our designers about how Octopus Flux could work with your chosen battery system

Using Octopus Flux with other batteries

Octopus Flux can also be used with other batteries, but these don’t have Tesla’s smart forecasting of tomorrows expected generation.  Instead a degree of manual programming will be needed.  In fact, some people prefer having the control themselves, rather than relying on the technology to manage this on their behalf.

You will need to set discharge times and limits for the battery to tell it to discharge at peak times and import when electricity is in the super-cheap rate.  You will want to adjust this seasonally, so that you don’t end up overfilling the battery overnight in summer.

Although this might seem crude, it’s actually not a disaster if this isn’t set up perfectly.  The export price paid in the middle of the day is still higher than the import price in the middle of the night.  So even if you do end up spilling some electricity back to the grid during the day, you’ll still make money!

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Using Octopus Flux with Solar

It is possible to use Octopus Energy’s Flux tariff with just solar, but it works much more favourably for you if you have a battery.

When using with solar, you will see a standard export tariff paid during the day, but a higher export rate paid between 16:00 and 19:00.  This is obviously beneficial in summer when you can generate into the evening (especially if you turn the oven off and have salads and a BBQ instead!).

However, you should also be aware of the reverse situation if you are using Octopus Flux without a battery.  Winter generation won’t exist in the evening period, leaving you exposed to higher import prices.

Using Octopus Flux with just solar will also favour homes with a more westerly facing array which will maximise generation at peak times.

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