Mr. EV

Solar & battery savings

Solar & battery installed by Heatable

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

Dec 2025 1 Dec 2025 – 31 Dec 2025 Updated 31st August 2026
Total benefit
£164
Saved on bills
£153
Earned exporting
£11
Top solar day
9.7
kWh on 30 Dec 2025
Solar generated
164
kWh · 57% used at home
Battery discharged
585
kWh · £116 of the saving
Exported
71
kWh sold back to the grid
EV charging
£32
192 kWh · not counted as saving
Would have paid
£551
with no solar and no battery
Actually paid
£398
before export payments and standing charge
Household use
2,090
kWh · 4% not bought from the grid
Paid back
22%
£4,118 of £18,990 · 5.4 yrs to go
Heating
1,140
kWh · £197 of the bill
By day 1 Dec → 31 Dec
Benefit £164
Solar 164kWh
Used 2,091kWh
Battery 585kWh
Exported 71kWh

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 24.2% 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.