Back in March I wrote about Octopus Flux being a game changer for solar owners. Since getting an EV I've found it has been difficult to decide on a single tariff. This is because the EV and solar both compromise each other in respect to import and export.
Whilst the Octopus Flux tariff gives one of the highest SEG export rates, there is only a short 3 hour low cost 'flux' period at 18p per kWh. This 3 hour period was quite short for EV charging as I could only put round 21kWh in the EV during this time. That was enough for around 75 miles in our EV. This meant I needed to charge every night, and sometimes charge at the daytime rate if I needed more in the EV battery for the next days journeys.
Up to now Octopus Energy EV tariffs were only compatible with the standard 4.1p per kWh SEG rate. This meant whilst the cost of charging the EV was much lower at 9p per kWh on Octopus Go you lost out on the SEG export rate.
Octopus change EV tariff SEG rates
In September 2023 Octopus Energy changed the SEG export rates that were compatible with their EV tariff's. A new Octopus Outgoing Fixed Lite was created to work with the Octopus Go EV tariff. This increased the SEG export rate to 8p per kWh exported. That was nearly double the standard SEG export rate of 4.1p, but around a third of the SEG export rate that I averaged on Octopus Flux of 22p per kWh exported during the summer months.
Intelligent Octopus Go on the other hand was now compatible with the Outgoing Octopus Fixed SEG export tariff giving 15p per kWh exported. When combined with the Intelligent Octopus Go low cost import rate of 7.5p per kWh its easy to see you get the lowest cost unit rate of all electricity tariffs to charge your EV, but also a great SEG export rate of 15p per kWh exported.
If I compare the import cost and export revenue for our actual figures from May to September for the Octopus tariffs:
* Octopus Flux
* Octopus Go
* Intelligent Octopus Go
I've worked out the import cost and export revenue for each of these tariffs in the tables below.
You can clearly see in the tables above there isn't much between Octopus Flux and Octopus Go. Both tariffs would work out to be an overall cost of around £90 to £100 over the five months. This is because what you gain on export with Octopus Flux you lose on additional import cost, and vice versa of Octopus Go.
If you compare the import cost and export revenue over these five months of Intelligent Octopus Go there would actually have been a net gain of around £50 over those five months. This is because the export revenue is greater than the imported electricity cost. Whilst the export rate at 15p per kWh is lower than the Octopus Flux tariff's higher 22p per kWh export rate, the import rate is much lower at only 7.5p compared to 18.5p per kWh
If you have a home battery there is also another benefit to Intelligent Octopus Go. The important aspect to note is the export rate (15p per kWh) is double the low period cost rate (7.5p per kWh). This means you can charge the home battery during the low cost rate at 7.5p per kWh, which lowers your home electricity costs, but also means because you can import at such a low rate it makes more sense to full your home battery overnight. This means your home battery will need be full every morning so you can pretty much export all solar generation during the day at 15p per kWh. This should mean a high percentage of solar generation is exported.
What this means is solar diverters such the Myenergi Zappi don't make as much financial sense. This is because charging an EV during the day (15p per kWh) would cost more than charging overnight (7.5kWh). Where it does make sense is where you may need a little top up and cannot wait until the night. Charging off solar generation during the day is cheaper than charging off imported day time rate (31p per kWh).
EV and Zappi COMPATIBILITY for Intelligent Octopus Go tariff
Intelligent Octopus Go is unusual in that it either needs a compatible EV or EV charger for you to be eligible for the EV tariff. This is because of the way the tariff works. Rather than have a set low cost period each day where you schedule your EV charge charge within these time, you leave this to Octopus to create a smart charging schedule based on the amount of charge you need and when you need the EV. The reason for this is because they will schedule the EV charging to periods where it can benefit the national grid by balancing loads. By giving Octopus this ability they give you their lowest cost rate, so it win win for both parties.
Unfortunately when I chose the Hyundai Ioniq 5 as our EV I knew it wasn't compatible with Intelligent Octopus Go. I also knew the Myenergi Zappi charger wasn't compatible either. I could only hope at some point in the future either the Ioniq 5 or Zappi became compatible as there was talk of both being looked at by Octopus. Whilst I was happy to wait, this wasn't helped when Octopus changed the SEG rates in September 2023 and neither were still compatible.
Finally, the MyEnergi Zappi becomes compatible with Intelligent octopus Go
In October 2023 I received a surprise email from Alex at Octopus Energy inviting me to early access for Intelligent Octopus Go with Myenergi Zappi.
Straight away that evening I applied to change over to Intelligent Octopus Go. I have to say it was quite an easy process via the Octopus app.
Setting up my first Intelligent charge schedule was pretty easy. All you have to do it select the amount of charge you want to add (in x %) and the time by which you would like the EV to be ready by. Once this information is entered Octopus will map a smart charge schedule.
Will our Home Battery drain when the EV charges?
Our Zappi charger isn't hard wired in a way which will prevent the home battery from discharging. As discussed previously in 'we've added a home battery' there is a work around by setting the battery to charge during the EV charging period.
I've reset the home battery charge period to coincide with the normal 2330 to 0530 low cost period of Intelligent Octopus Go. Octopus will likely map the smart charge schedule within this period. I will have to monitor the smart charge mapping and adjust the home battery charge schedule to suit if the its schedules charges outside this period.
The change to Intelligent Octopus Go should be my last tariff change as it should suit both summer and winter. I feel it's currently the best compromise for both EV and solar users. There is the additonal benefit that it will help the national grid balance loads by allowing Octopus to schedule the charging of the EV. It allow us to export our solar generation which provides others with green electricity during the day and gives us extra income as we will likely export majority of monthly generation. Due to our home battery it lets us drop the cost of imported electricity for our home to an average of 8p per kWh, as our home battery can store sufficient electricity to cover our daily use. This is a huge saving on the standard unit rate that's currently around 28p per kWh.