Mr. EV

Solar & battery savings

Solar & battery installed by Heatable

£150 off solar £75 off a battery £150 off a heat pump £150 off air conditioning £50 off your Octopus bill Referrals

Sep 2026 1 Sep 2026 – 30 Sep 2026 Updated 8th November 2026
Total benefit
£165
Saved on bills
£118
Earned exporting
£46
Top solar day
45.3
kWh on 5 Sep 2026
Solar generated
818
kWh · 53% used at home
Battery discharged
226
kWh · £24 of the saving
Exported
386
kWh sold back to the grid
EV charging
£15
196 kWh · not counted as saving
Would have paid
£129
with no solar and no battery
Actually paid
£10
before export payments and standing charge
Household use
454
kWh · 84% not bought from the grid
Paid back
24%
£4,536 of £18,990 · 5.5 yrs to go
Heating
3
kWh · £0 of the bill
By day 1 Sep → 30 Sep
Benefit £165
Solar 819kWh
Used 454kWh
Battery 226kWh
Exported 386kWh

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 5.2% 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.

By day 1 Sep → 30 Sep
Benefit £165
Solar 819kWh
Used 454kWh
Battery 226kWh
Exported 386kWh