Mr. EV

Solar & battery savings

Solar & battery installed by Heatable

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

Jul 2026 1 Jul 2026 – 31 Jul 2026 Updated 31st August 2026
Total benefit
£286
Saved on bills
£136
Earned exporting
£149
Top solar day
68.5
kWh on 3 Jul 2026
Solar generated
1,791
kWh · 31% used at home
Battery discharged
251
kWh · £11 of the saving
Exported
1,243
kWh sold back to the grid
EV charging
£13
110 kWh · not counted as saving
Would have paid
£144
with no solar and no battery
Actually paid
£7
before export payments and standing charge
Household use
538
kWh · 93% not bought from the grid
Paid back
22%
£4,118 of £18,990 · 5.4 yrs to go
Heating
23
kWh · £1 of the bill
By day 1 Jul → 31 Jul
Benefit £286
Solar 1,791kWh
Used 537kWh
Battery 251kWh
Exported 1,243kWh

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 3.4% 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.