Is it better to store solar or export it?
Usually store it in your solar battery, because a kWh you would otherwise buy later is worth more than a kWh you sell now. But not always: a full battery, an evening export price, or a cheap night to refill from can each turn it round. Here are the real prices, the rule that decides it, and what deciding it every half hour was worth.
Store it if what you would pay later beats what you are paid now.
A kWh of spare sun at lunchtime can go two ways. Sold, it earns the export price now. Stored, it saves what the house would have paid for a kWh later, less the little a battery loses going in and out, about a tenth.
One kWh of spare sun at 1pm, this autumn
- Sold on Outgoing Octopus: 12pThe same flat rate at any hour.
- Sold on Agile Outgoing: about 10pIts average between 10am and 3pm from 3 September to 7 October 2026.
- Stored for an Agile evening: about 42p savedAgile averaged 46.79p from 4pm to 7pm over the same weeks. Less the tenth lost in the battery, that is about 42p.
- Stored on a single rate at the price cap: about 24p saved26.32p a kWh from 1 October, less the same tenth.
Three times selling beats storing.
Storing wins most half hours. These are the exceptions, and a battery that never makes them leaves money behind.
- When the battery will be full anywayOn a sunny day a battery can fill by early afternoon. Sun stored at 11am only pushes out sun at 2pm, so it is better to sell in the half hours that pay most and keep room for the rest.
- When export pays more in the evening than you will pay overnightAgile Outgoing’s best three hours of each day averaged 24.1p this autumn, and Agile’s cheapest four hours 15.2p. Selling in the evening and refilling at night cleared 7.2p a kWh on 21 of 35 days, after what the battery loses.
- When the tariff pays for the eveningFlux pays most for export from 4pm to 7pm, so sun held back for those hours earns more than sun sold at midday.
Agile Octopus and Agile Outgoing prices as Octopus published them for North West England, 3 September to 7 October 2026, times in UK clock time. The price cap is Ofgem’s average single rate by Direct Debit from 1 October 2026. Read 12 October 2026.
Midday export pays least all year round.
Agile Outgoing in the same region, season by season. The middle of the day, when the sun goes out, stayed under the 12p flat rate in every season. The evening is where it moved.
Agile Outgoing, 10am to 3pm and the best 3 hours
- Winter: 9.2p and 16.9pNovember 2025 to February 2026. Selling at the evening best and refilling at the night’s cheapest cleared 1.6p a kWh, on half the days.
- Summer: 9.2p and 19.1pJune to August 2026. Eight in ten midday half hours paid less than 12p.
- Autumn: 10.1p and 24.1p3 September to 7 October 2026.
A battery left to itself stores everything. That cost hundreds a year.
Left to itself, a battery charges from any spare sun and sends out only what it has no room for. Orza decides store or sell, and when to buy, again every half hour. Over a full year of 40 modelled homes with a 9.5 kWh battery, the difference for the average home was:
Saved a year by planning, average home
- Flux: £278.86Holding sun for the evening, and selling it then.
- Agile with Outgoing Octopus, 12p: £260.14
- Agile with Agile Outgoing: £200.05
- Agile, nothing paid for export: £85.81With no export price, it only moves the home’s own use and sun.
Before you set your battery to store everything.
The prices here are one region’s. These are the things that change the answer for yours.
All our guidesIf I’m not paid for export, should I always store?
Yes. A kWh sent out earns nothing, so every kWh the battery can hold is worth storing. The only question left is when to use it, and on a tariff whose price moves, the evening is usually best.
How much does a battery lose?
Some of what goes in never comes back out, as heat in the battery and the inverter. For the real home in our guides it is about a tenth, which is why a kWh stored is worth a little less than a kWh bought.
Does my export limit change this?
It caps how fast you can sell, so on a full battery and a sunny day, sun beyond the limit is lost rather than sold. What an export limit is, and what it cost one home.
Which export tariff suits storing?
A flat rate suits a home that sells mostly at midday. A rate that pays most in the evening suits a battery that can hold sun for those hours. How the two compared for one real home.
What does Orza cost?
Nothing during the beta, and no card is needed to join.
Store or sell, decided every half hour for your own home.
Free during the beta. Connect in a few minutes, and start in Monitor only.