Mar 2026 1 Mar 2026 – 31 Mar 2026 Updated 8th November 2026
Total benefit
£298
Saved on bills
£275
Earned exporting
£24
Top solar day
43.7
kWh on 26 Mar 2026
Solar generated
782
kWh · 75% used at home
Battery discharged
672
kWh · £107 of the saving
Exported
197
kWh sold back to the grid
EV charging
£18
257 kWh · not counted as saving
Would have paid
£444
with no solar and no battery
Actually paid
£169
before export payments and standing charge
Household use
1,738
kWh · 32% not bought from the grid
Paid back
24%
£4,536 of £18,990 · 5.5 yrs to go
Heating
976
kWh · £74 of the bill
By day 1 Mar → 31 Mar
Solar Used Battery Exported Benefit (£) Cash flow (£)
76 0 kWh £14 0 −£10

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 5.4% 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 day 1 Mar → 31 Mar
Solar 782kWh Used 1,739kWh Battery 672kWh Exported 197kWh Benefit (£) £298 Cash flow (£) −£146
76 0 kWh £14 0 −£10
1 Mar 4 Mar 7 Mar 10 Mar 13 Mar 16 Mar 19 Mar 22 Mar 25 Mar 28 Mar 31 Mar