Since moving in 25 Oct 2024 – 9 Nov 2026 Updated 8th November 2026
Total benefit
£4,536
Saved on bills
£2,951
Earned exporting
£1,584
Top solar day
72.0
kWh on 13 Jun 2026
Solar generated
17,677
kWh · 35% used at home
Battery discharged
8,747
kWh · £1,158 of the saving
Exported
11,560
kWh sold back to the grid
EV charging
£332
4,539 kWh · not counted as saving
Would have paid
£8,390
with no solar and no battery
Actually paid
£5,439
before export payments and standing charge
Household use
33,377
kWh · 15% not bought from the grid
Paid back
24%
£4,536 of £18,990 · 5.5 yrs to go
Heating
16,971
kWh · £3,252 of the bill
By month Oct → Nov
Solar Used Battery Exported Benefit (£) Cash flow (£)
2,960 0 kWh £333 0 −£741

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 Oct → Nov
Solar 17,677kWh Used 33,377kWh Battery 8,748kWh Exported 11,560kWh Benefit (£) £4,535 Cash flow (£) −£3,855
2,960 0 kWh £333 0 −£741
Oct Jan Apr Jul Oct Jan Apr Jul Oct Nov