Mr. EV

Solar & battery savings

Solar & battery installed by Heatable

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

2025 1 Jan 2025 – 31 Dec 2025 Updated 31st August 2026
Total benefit
£2,187
Saved on bills
£1,224
Earned exporting
£963
Top solar day
70.7
kWh on 16 May 2025
Solar generated
8,148
kWh · 21% used at home
Battery discharged
4,662
kWh · £585 of the saving
Exported
6,422
kWh sold back to the grid
EV charging
£248
1,867 kWh · not counted as saving
Would have paid
£2,479
with no solar and no battery
Actually paid
£1,254
before export payments and standing charge
Household use
9,917
kWh · 11% not bought from the grid
Paid back
22%
£4,118 of £18,990 · 5.4 yrs to go
Heating
3,751
kWh · £482 of the bill
By month Apr → Dec
Benefit £2,187
Solar 8,148kWh
Used 9,917kWh
Battery 4,662kWh
Exported 6,422kWh

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.