Usually the summer months are when our solar system should produce its highest generation of the year, but considering we've had such a great spring season it may not be the best season of the year this time.
Our Monthly Solar Performance
June 2025
Generation this month was a huge 553.7kWh, much higher than the estimated monthly solar generation of 443kWh. It was just 8.3kWh short of June 2023's record highest ever month generation of 562kWh and the third consecutive month of generation over 500kWh!
470kWh of solar electricity was exported this month, producing a SEG export payment of £70.50 via Outgoing Octopus at 15p/kWh.
Generation per day over the month of June was very good, especially the middle of the month.
There were only 1 day below 10kWh and 11 days over 20kWh. Our highest daily generation was 19th June with 24.3kWh. The lowest was 8.6kWh on 5th June.
July 2025
Unfortunately the consecutive +500kWH months ended in July. The month started brilliantly with 261kWh generation by 14th July (average of 18.6kWh per day). If it had carried on at that rate for the month we could have potentially reached 576kWh. Unfortunately we generated just 212kWh in the remaining 17 days (average of 12.5kWh per day) hence we ended with a total of 473kWh. That was still higher than the expected 452kWh estimated generation for July so it wasn't all bad.
Our self consumption this month was 11%, providing us with 79kWh of 'green' electricity for our home (note: we don't charge the EV off the solar generation).
We exported 390.9kWh of the solar generation to the national grid (82.6% of the overall solar generation).
Overall there were 4 days were under 10kWh and 6 days were over 20kWh. The highest being 25.5kWh on 8th July.
august 2025
August's generation was slightly below July's generation with 460kWh. It was higher than the estimated generation of August (actual generation was 115% of the estimated 400kWh). Overall is was our lowest generation in August compared to previous years (478kWh in 2024 & 472kWh in 2023).
The highest daily generation was 23.7kWh on 8th August. There were only 4 days under 10kWh generation, one of which was only 5.6kWh on 16th August.
Our self use consumption (11%) as a percentage of total consumption is still very low. This is because even during the summer months we charge the home battery overnight at 7p/kWh rather than store solar generation.
Generation Performance - edit red.
Generation performance in June was stunning and carried on the +500kWh months from spring.
July was 5% above the expected generation with 473kWh but didn't reach the height of 500+kWh like previous months.
August generation was still above estimated generation at 460.7kWh.
Overall our actual generation has performed better than the estimated expected generation for our 3.6kW system for six consecutive months.
For the year so far our actual generation is still ahead of the estimated generation by 469.7kWh. Thats 16% ahead of the estimated generation at this point of the year.
Summer generation was close to previous years but was our lowest summer generation in 3 years. For the year so far we are still ahead because of how good the spring months were.
Savings - edit this
We exported 1250.4kWh back to the national grid during the summer months. Self use consumption accounted for 237.3kWh.
Savings continued from spring into the summer month. Summer brought total savings of £311.66.
There was £187.56 revenue from the 1250.4kWh exported. Self use produced savings of £62.82. Home unit rate savings from charging the battery overnight gave savings of £58.24. Free electricity from Octopus' free electricity hours provided additional savings of £3.05.
Overall I'm impressive with a total savings so far this year of £767.71. If I included unit cost savings from electricity consumed by the EV overall savings would be around £1705.51 so far.
Summary
Key Statistics for summer:
* 1487.7kWh generated
* 1250.4kWh exported
* 237.3kWh self sufficiency from solar
* £311.66 saved
* Highest daily generation - 25.5kWh on 8th July 2025
Summer 2025 compared to previous years
Whilst 2025 has been a fantastic year for solar generation (the spring season was just amazing), the summer season has in comparison, surprisingly, been on par with previous years.
In summer of 2025 there wasn't any record high generation months.
June - 3rd (553.7kWh)
July - 2nd (473kWh)
August - 3rd (460.7kWh)
Summer 2025 saw a total generation of 1488kWh. This was actually the lowest summer generation in 3 years when compared to 1498kWh in 2023 and 1519kWh in 2024. Each of those years were all over the estimated summer generation of 1295kWh.
When we look at the estimated generation versus the actual generation figures we can see that April to August has performed above the expected generation consistently for 3 consecutive years.
We are only 342kWh from meeting the estimated annual generation for our 3.6kWh solar solar. We could nearly match the annual generation if we meet the estimated generation in September. It would be amazing if we can match the annual estimated generation in just 9 months.
