Year 2 7 Apr 2026 – 9 Nov 2026 Updated 8th November 2026
Total benefit
£1,727
Saved on bills
£1,156
Earned exporting
£571
Top solar day
72.0
kWh on 13 Jun 2026
Solar generated
8,226
kWh · 42% used at home
Battery discharged
2,373
kWh · £282 of the saving
Exported
4,759
kWh sold back to the grid
EV charging
£112
1,475 kWh · not counted as saving
Would have paid
£1,423
with no solar and no battery
Actually paid
£267
before export payments and standing charge
Household use
5,294
kWh · 59% not bought from the grid
Paid back
24%
£4,536 of £18,990 · 5.5 yrs to go
Heating
1,432
kWh · £72 of the bill
By month Apr → Nov
Solar Used Battery Exported Benefit (£) Cash flow (£)
1,791 0 kWh £326 0 −£51

This tool was built with Claude

Every line of it — the Octopus and AlphaESS clients, the settlement model, this screen — was written in conversation with Anthropic's Claude. Here is what that cost.

Tokens
110.8million
across 364 requests · measured
Electricity
2.3kWh
estimated · 0.7–8.3
Carbon
294g CO₂e
estimated · 83–1,039
Fresh water
2.5litres
cooling only · 0.7–9.0

Roughly 3.3% of what this roof made on its best day.

Only the token count is measured. Anthropic publishes no per-token energy figures, so the rest is inferred from Google's first-party measurements of its own models and from published per-token estimates — two methods that disagree by about ninety times, which is why these are ranges and not numbers. The water figure covers datacentre cooling only, not the water used to generate the electricity, so read it as a floor. Model training is excluded: it is shared across everyone who ever uses the model and cannot be fairly attributed to one project.

By month Apr → Nov
Solar 8,226kWh Used 5,294kWh Battery 2,373kWh Exported 4,759kWh Benefit (£) £1,727 Cash flow (£) £304
1,791 0 kWh £326 0 −£51
Apr May Jun Jul Aug Sep Oct Nov