September Electricity
I managed to maintain a 2.62% Peak/Off-Peak ratio, compared to 17.6% in 2025.
A pretty sunny month, way more so than last year.
Electricity costs for the month of September: £106.34 for 2026, £149.85 for 2025.
Electricity demand for the month of September: 1469kWh for 2026, 1709kWh for 2025 (2026 does not include EcoFlow figure – see below).
The off-peak/peak/SC values for July were £0.069/0.30269/0.53892 for 2026 vs £0.07/£0.28959/0.47606 for 2025, same as last month.
This can also be seen in the month on month usage vs cost graphs where my usage is about the same, however my costs have gone down each year:
Ecoflow Batteries:
The graphs show a total of 450kWh (333 + 117) of usage, 114kWh (71 +43) of which came from the batteries and 333kWh (261 + 72) came from the ‘grid’ after the batteries were exhausted.
This means that I have moved an additional 114kWh of usage from peak to off-peak or £26.64 (114 * (0.30269 – 0.069)) of additional savings not captured elsewhere, this should be added to the demand figure above, taking it to from 1469kWh to 1583kWh
September Solar:
Actual production for September significantly exceeded the forecast.
The various arrays produced the following levels of energy: Garage 216.2kWh, Office 174.09kWh, East 117.73kWh, West 143.65kWh for a total of 651kWh, this compares to 645kWh for September 2025, so slightly up on last year.
I produced more than last year and also managed to export 326kWh compared to 130kWh in 2025, for a total saving of £49.01, around 250% more than last year’s figure of £19.57.
This is largely due to the extra batteries, allowing me to make it through most days without drawing any peak electricity and thereby allowing me to export more solar and also empty my Enphase batteries at the end of the day.
The import costs of £106.34 less the export savings of £49.01 means my net cost for September was £57.33for 1583kWh of demand making my average rate £.0036/kWh.
September Gas:
Heating was turned off for the entirety of this month.
Quite a warm September my cost was slightly up on last year, £44.07 vs £30.56, despite my usage being down, 371kWh vs 468kWh, the average cost per kWh was up at 0.0922 as compared to 0.0464 in 2025, war in the Middle East, is still having an adverse effect on the gas prices.
Gas costs:
There were eight Saver Sessions this month, my Home Assistant automation signed me up automatically
I received notification about these sessions via emails sent round midday of the day in question.
1st September between 18:00 and 19:00, offering 68 Octopoints (8.50p) per kWh saved and 1 free weekend ‘happy hour’ (for 2 successful sessions).
2nd September between 20:00 and 21:00, offering 56 Octopoints (7.00p) per kWh saved and 1 free weekend ‘happy hour’ (for 2 successful sessions).
3rd September between 18:00 and 19:00, offering 61 Octopoints (7.625p) per kWh saved and 1 free weekend ‘happy hour’ (for 2 successful sessions).
7th September between 18:00 and 19:00, offering 61 Octopoints (7.625p) per kWh saved and 1 free weekend ‘happy hour’ (for 2 successful sessions).
10th September between 19:00 and 20:00, offering 76 Octopoints (9.05p) per kWh saved and 1 free weekend ‘happy hour’ (for 2 successful sessions).
11th September between 19:00 and 20:00, offering 1 free weekend ‘happy hour’ (for 2 successful sessions).
14th September between 18:00 and 19:00, offering 85 Octopoints (10.625p) per kWh saved and 1 free weekend ‘happy hour’ (for 2 successful sessions).
15th September between 18:00 and 19:00, offering 72 Octopoints (9.00p) per kWh saved and 1 free weekend ‘happy hour’ (for 2 successful sessions).
16th September between 18:00 and 19:00, offering 82 Octopoints (10.25p) per kWh saved and 1 free weekend ‘happy hour’ (for 2 successful sessions).
17th September between 18:00 and 19:00, offering 68 Octopoints (8.50p) per kWh saved and 1 free weekend ‘happy hour’ (for 2 successful sessions).
21st September between 18:00 and 19:00, offering 75 Octopoints (9.375p) per kWh saved and 1 free weekend ‘happy hour’ (for 2 successful sessions).
22nd September between 18:00 and 19:00, offering 79 Octopoints (9.875p) per kWh saved and 1 free weekend ‘happy hour’ (for 2 successful sessions).
24th September between 18:00 and 19:00, offering 68 Octopoints (8.50p) per kWh saved and 1 free weekend ‘happy hour’ (for 2 successful sessions).
25th September between 18:00 and 19:00, offering 75 Octopoints (9.375p) per kWh saved and 1 free weekend ‘happy hour’ (for 2 successful sessions).
28th September between 18:00 and 19:00, offering 75 Octopoints (9.375p) per kWh saved and 1 free weekend ‘happy hour’ (for 2 successful sessions).
30th September between 18:00 and 19:00, offering 64 Octopoints (8.50p) per kWh saved and 1 free weekend ‘happy hour’ (for 2 successful sessions).
Since they were all were offering less than my export guarantee and way less than the peak rate (30.269p/kWh), I made no effort to charge the batteries beforehand, or discharge them during the sessions.
The savings are calculated against the previous 10 days usage during the same period, and since my usage is usually at, or near zero during these times, I would need to be discharging my batteries to make any difference.
My house draws from the grid when I am force discharging the batteries, which can have a significant impact on any potential savings – hence why I discharge my batteries each night at the start of the off-peak window.
As a result my savings during these sessions were somewhat low:
I saved 0.24kWh on the 1st, which netted me 16 Octopints (£0.02) and the first half of a free hour.
I saved 0.29kWh on the 2nd, which netted me 16 Octopints (£0.02) and the first half of a free hour.
I saved 0.26kWh on the 3rd, which netted me 16 Octopints (£0.02) and the first half of a free hour.
I saved 0.26kWh on the 7th, which netted me 16 Octopints (£0.02) and the first half of a free hour.
I saved 0.21kWh on the 10th, which netted me 16 Octopints (£0.02) and the first half of a free hour.
I saved 0.21kWh on the 11th, which netted me 16 Octopints (£0.02) and the first half of a free hour.
I saved 0.19kWh on the 14th, which netted me 16 Octopints (£0.02) and the first half of a free hour.
I saved 0kWh on the 15th, which netted me 0 Octopints (£0.00).
I saved 0.20kWh on the 16th, which netted me 16 Octopints (£0.02) and the first half of a free hour.
I saved 0.24kWh on the 17th, which netted me 16 Octopints (£0.02) and the first half of a free hour.
I saved 0kWh on the 21st, which netted me 0 Octopints (£0.00).
I saved 0.20kWh on the 22nd, which netted me 16 Octopints (£0.02) and the first half of a free hour.
I saved 0kWh on the 24th, which netted me 0 Octopints (£0.00).
I saved 0kWh on the 25th, which netted me 0 Octopints (£0.00).
I saved 0kWh on the 28th, which netted me 0 Octopints (£0.00).
I saved 0.25kWh on the 30th, which netted me 16 Octopints (£0.02) and the first half of a free hour.
A total saving of £0.22 – absolutely not worth the effort to even bother doing anything regarding these sessions, however I have earned 5 and a half free hours of free electricity that I can use on a Sunday, which is most certainly worth having.
I now have 9 free hours to use, although I can only use one on any given Sunday, these could be very useful in the winter for charging up my batteries