January Solar Generation and Export Numbers
Here is the overview for January 2025. Agile Octopus pricing was high once again in Janaury, on some days it was close to its cap of £1 kWh. Of course the batteries saved us from these prices. Saying that one day I should have topped up the batteries even though the rate was high. This led us to being on the grid during the 99p slots.
We had three Saving Sessions this month. These earned us 1544 Octopoints worth £1.93. Last year that would have been worth a lot more. The Demand Flexibility Service (DFS) in 2025 is a disaster and should be reviewed by NESO. For those on the price cap, the until rate when up to £0.25575 per kWh for electricity and £0.0626 for gas
Saying all that, our average Agile Octopus cost was 19.13p per kWh. Last January it was just 12.34p. That is still 6p under the price cap. I would still rather be on Agile Octopus.
The heat pump is working well. We had some very cold days at the start of the month, well below freezing. The house was still lovely and warm. In fact my wife is saying it is too hot. We now have the heating come on at 5am at 20c until 7pm when it goes off. That does not mean it is running all day, but it does keep the house a nice constant temperature.
As you can see below this month the heat pump was more expensive than gas this time last year. That is due to the Agile pricing mentioned above.
Heat Pump v Gas
| Month | Difference | Gas (2024) | Electricity (2024) | Gas (2025) | Electricity (2025) | |
|---|---|---|---|---|---|---|
| January | +£69.48 | £86.26 | £61.05 | £9.79 | £207.00 |
You can see the heat pump numbers here.
The worst generation day was the 1st with only 0.60 kWh. The best was the 25th when 6.50 kWh was generated.
The best export day was the 26th with 2.60 kWh. This was a force discharge from the battery during a Saving Session. The best solar export day was the 1st with 0.30 kWh.
As solar panels output declines over the years I have added the 2023 generation to the table at the bottom. Of course weather comes into it as well, but I thought it would be interesting to track. I have now added this post that shows each year as a graph.
This year we have had 0 days where we generated more solar than we consumed, and 0 days more solar was generated than we imported from the grid.
January 2025 Octopus Energy bill
Octopus Watch Tariff Comparison Report. This does not include exporting
Best Solar Generation
| Date | kWh | |
|---|---|---|
| Generation | 26th May 2023 | 32.90 |
| Front generation | 14th June 2023 | 19.80 |
| Back generation | 7th June 2023 | 14.70 |
| Worst generation | 12th December 2022 | 0.20 |
Solar Generation January 2025
| Date | kWh | |
|---|---|---|
| Best generation | 25th | 6.50 |
| Best front generation | 30th | 5.00 |
| Best back generation | 11th | 1.70 |
| Worst generation | 1st | 0.60 |
| Worst front generation | 1st | 0.30 |
| Worst back generation | 1st | 0.30 |
Best Solar Export and Profit
| Date | kWh | Profit | |
|---|---|---|---|
| Exported kWh | 15th June 2024 | 22.20 | |
| Exported profit | 15th June 2024 | 22.20 | £3.15 (15p kWh) |
| Profit day | 14th April 2024 | 18.20 | £2.67 |
Solar/Battery Export and Profit January 2025
| Date | kWh | Income/Cost | |
|---|---|---|---|
| Best kWh export - Battery & Solar | 26th | 2.60 | |
| Best kWh export - Solar Only | 1st | 0.30 | |
| Best export profit | 26th | 2.60 | £0.39 (15p kWh) |
| Cheapest Day | 6th | £2.84 |
The graph below shows the generation for both front and back panels
The graph shows the generation for both front and back panels
Showing generation, battery discharge, battery charging, export, import to use and consumption for 2025
Generation
Overview for Janaury
The graph below shows the generation for each day
Graph showing production for the month
The graphs below show the generation split between the front and back panels
Graph showing production for the front facing panels
Graph showing production for the back facing panels
The graphs below show the yearly generation split across both the back and front panels
Front panel generation for for 2025
Back panel generation for 2025
Octopus Agile
The costs shown here do include the standing charge. Any comparisons are compared to the unit cost if we were not on Octopus Agile, which is £0.25575 kWh. This is the new unit cost after the price cap took affect. The standing charge was 0.48788p
As mentioned above we are still using overnight slots due to my new export strategy. The average slot price was quite high this month.
December Grid Information
| Standard Tariff | 25.575p | ||
| Standing Charge | 48.788 | ||
| Cost from the grid | £194.18(Agile) | £259.59 (Standard) | |
| Savings including export | £69.46 | ||
| Exported | 27 kWh | £4.05 @ 15p kWh | |
| Agile slots used | 351 | ||
| Agile plunge slots used | 10 | ||
| Average Agile slot price | 19.13 | ||
| Cheapest slot | -1.43p | ||
| Most expensive slot | 48.51p | ||
| House consumed | 974.90 kWh | ||
| Solar generated 2025/2024 | 83.50 kWh | 97.60 kWh | |
| Percentage generated by solar | 9% | ||
| Self Sustained Days 2025 (More solar than consumed) | 0 | ||
| Self Sustained Days 2025 (More solar than we imported) | 0 | ||
Here is the Octopus Watch report summary
Octopus Watch summary
Featured posts
Solar panel performance declines over the years. I thought it might be interesting to see how mine compares. Of course weather comes into it, but hopefully this will be a useful guide.