Energy Calculators
Run the numbers on solar, batteries, and smart tariffs. Built on real data from my own system — not manufacturer estimates.
🐙 Octopus Tariff Finder
Answer a few questions about your setup and usage. I'll score every Octopus tariff and tell you which one suits you — and why.
1. Do you have a home battery?
2. Do you have solar panels?
3. Do you have an electric vehicle?
4. How flexible are you about when you use electricity?
5. What's your annual electricity usage?
6. How do you feel about variable bills?
☀️ Solar ROI Calculator
Uses the AIKO 455W N-Type ABC degradation profile: ≤1% year 1, ≤0.35%/yr years 2–30.
With battery + Predbat, 70%+ is realistic
| Year | Generation | Annual saving | Cumulative |
|---|
🐙 Agile vs Standard Tariff
Works out how much you save on Octopus Agile with smart charging vs a fixed-rate tariff.
My average with Predbat is ~11–13p
🔋 Battery ROI Tool
Calculate payback for a home battery on any tariff — works for Fox ESS, Givenergy, Powerwall and more.