Mr. EV

Solar & battery savings

Solar & battery installed by Heatable

£150 off solar £75 off a battery £50 off your Octopus bill referral

Mar 2026 1 Mar 2026 – 31 Mar 2026 Updated 31st August 2026
Total benefit
£301
Saved on bills
£277
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 · £109 of the saving
Exported
197
kWh sold back to the grid
EV charging
£32
257 kWh · not counted as saving
Would have paid
£450
with no solar and no battery
Actually paid
£172
before export payments and standing charge
Household use
1,738
kWh · 32% not bought from the grid
Paid back
22%
£4,118 of £18,990 · 5.4 yrs to go
Heating
976
kWh · £75 of the bill
By day 1 Mar → 31 Mar
Benefit £301
Solar 782kWh
Used 1,739kWh
Battery 672kWh
Exported 197kWh

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.