I recently wrote about how we use Intelligent Octopus Go import rates and Outgoing Octopus export to our advantage (how to increase your solar generation).
At the end I mentioned that I can't see this current oddity with Intelligent Octopus Go and Outgoing Octopus lasting forever. It just seems strange that I can export at a higher rate during the day and import at a lower rate overnight.
We initially started our solar journey on the Outgoing Octopus tariff in February 2023. At the time Outgoing Octopus export paid 15p/kWh and allowed us to combine it with the standard variable rate tariff. That had a daytime import rate of 35p/kWh (after the Energy Price Guarantee was applied).
Roll on 2 years and Outgoing Octopus export tariff was still 15p/kWh. That's amazing considering the standard variable is now 23% lower at 27.33p/kWh.
When we look at the export rate as a percent of the import rate the export rate had increase from 43% in March 2023 to 55% in May 2025, because the rate was still 15p/kWh.
When you look at the day and low period import rates of Intelligent Octopus Go tariff the day import rate is slightly higher than the standard variable import rate. This means the export rate as a percent of the day import rate it is 52%.
The export rate as a percent of low rate is an amazing 214%.
What can we learn from other tariffs?
Octopus Flux is another tariff for solar owners. Its has a combined import and export tariffs. The change in the unit rates from March 2023 to May 2025 is quite obvious. Whilst the peak period export rate is still around three quarters of the import, there has been a big drop in the export rate during the day from 69% to just 37%.
When you look at the low period import rate compared to the day period export rate you can see a big change from March 2023 to May 2025. The export rate is now much lower than import rate.
Export and Demand
When you look at the peak solar generation period between 11:00 and 13:00 it doesn't align with the peak electricity demand period that occurs between 18:00 and 22:00 in the evening.
Typical solar generation curve from our 3.6kWp system on a perfect solar day
Source: Imperial College London
Currently the higher export rate of Octopus Outgoing and lower import rate of Intelligent Octopus Go during the low period promotes charging your home battery during the low period and exporting solar generation during the day.
The future?
As more people install home solar and larger solar farms come online a single export rate throughout the day makes less sense as it doesn't manage generation and demand.
I can foresee a need to minimise solar export during the higher solar generation period which have but lower demand, and promote the storing of the solar generation to export later during the peak demand evening period.
A change to the Outgoing Octopus export tariff to bring oit more in alignment with Octopus Flux would likely make sense in the future as it would align export rate to maximum demand periods.
Having a lower export rate during the day and a higher export rate during the evening peak demand period would likely change users habits. We would likely minimise solar export during the day by diverting excess to home batteries or by charging an EV, and export the excess in our home batteries during the evening's higher export rate period.
This could also have an effect on the size of solar arrays and home batteries too. At present the larger your solar array the more you can generate and export making more in export. In the future I foresee home battery capacity needing to match the maximum daily generation. Larger solar arrays could become a hinderance if you couldn't use all of the solar generation yourself.
Our highest ever daily generation was 27kWh in June 2023. This would mean our home battery would need to be be 3-4 times its current 10kWh capacity to be able to store all solar of the solar and export it during the evening peak period.
In reality if the peak period was only 4 hrs long we couldn't export the full stored 27kWh in that time frame because our maximum output from our home battery is 3kW. This means in 4 hours we could export 12kWh of the 27kWh. We would therefore need to transfer some of the solar excess to an EV or use it within the home. Whether this was done by diverting the solar during the day to the EV or charging the EV later from the home battery we would need to change from our current habits.
Future technology improvements would likely automate this process just like how Intelligent Octopus Go manages over EV charging. Perhaps we may see an Intelligent Outgoing Octopus tariff in the future which aligns with Intelligent Octopus Go as the import tariff.
With the recent release of the Octopus Intelligent Drive Pack as a bolt tariff (single monthly price for EV Charging) I do wonder if the future will be different bolt on tariffs for different applications like the home, EV, heat pump, etc and with more emphasis of self use of solar generation rather than exporting. One thing we can be sure of is things will like change as the transition to renewables and EV's progresses.