Solar battery savings calculator
Already have a solar battery? Pick your tariff, your battery and how much electricity your home uses, and see what planning the battery every half hour saved over leaving it on its own schedule, for modelled homes like yours over a whole year.
Work out your saving
The five modelled homes nearest your use, about 4,100 to 5,000 kWh a year, saved £369 to £405 on Go with Outgoing Octopus.
Free during the beta. Modelled homes, not a quote for yours: how it is worked out.
Twenty homes, a whole year, the same battery two ways.
Each home ran for a year with its battery left on its own schedule, and again with Orza planning it every half hour. The saving is the difference between the two bills. The figure above is the middle of the five homes whose yearly use is nearest yours.
What went in
- Real useEach home’s half hours are a real household’s smart meter readings. The twenty used from about 3,400 to 13,000 kWh a year.
- Real prices and weather1 October 2025 to 30 September 2026, at the rates Octopus published for North West England, with the sun that came.
- Only what was known at the timeThe plan saw the weather forecast as it was issued and each day’s prices once they were published, never the day itself.
- Left on its own scheduleThe same battery storing spare sun and emptying into the house, as a battery does when nothing plans it.
- Left outStanding charges, which are the same either way, and any export limit. The panels face south.
Planning was worth £200 to £413 a year.
The average of the twenty homes on each tariff, against the same battery on its own schedule, with export paid.
| Tariff | 9.5 kWh battery, 4 kWp of panels | 13.5 kWh battery, 6 kWp of panels |
|---|---|---|
| Go with Outgoing Octopus | £401.70 | £405.40 |
| Flux | £278.86 | £413.46 |
| Agile with Outgoing Octopus | £260.14 | £230.42 |
| Agile with Agile Outgoing | £200.05 | £258.70 |
Saved a year by the average of 20 modelled homes, 1 October 2025 to 30 September 2026, planned against the same battery on its own schedule, on the same tariff. Standing charges are left out, and no limit was put on export.
Before you trust the number.
A year of twenty homes is strong evidence, not a quote. These are the things that change the answer for yours.
All our guidesWhy against my own battery, and not against no battery?
You already have the battery, so the question is what planning it adds. Against a home with no battery at all the figures would be larger, but most of that is the battery’s, not the plan’s. Is a solar battery worth it? has that comparison.
My tariff is not here.
These four are what have been modelled so far. Orza plans for whatever tariff you give it, from any supplier, including your own rates from a bill. Go, Agile or Flux with a battery? compares the three.
How close will my own saving be?
The range under the figure is how much the five homes nearest your use differed from each other. Your use through the day, your roof and your export limit move it too. Most homes may send 3.68 kW, which cuts what a large battery can sell; no limit was applied here.
What does Orza cost?
Nothing during the beta, and no card is needed to join. Orza plans your battery every half hour for your own tariff and home, and you can start in Monitor only, where it changes nothing.
See the figure for your own battery.
Free during the beta. Connect in a few minutes, and start in Monitor only.