What is an export limit, and does it cost you money?
Your connection to the grid can only send so much power back at once, and most owners have never been told the figure. On a tariff that pays for export, it can matter more than the tariff itself. Here is what the limit is, how to find yours, and what it was worth to one real home.
Most homes may send 3.68 kW to the grid without asking.
That is 16 amps on one phase, under the rule installers call G98. A bigger system needs the network operator’s approval first, under G99, and the approval often comes with a limit: 3.68 kW, sometimes more, occasionally none at all. Your inverter enforces it, whatever the sun and the battery could give.
What it changes
- How fast a battery can sellA battery that can give 12 kW still sells only as fast as the connection allows. On a half hour when export pays well, the rest waits.
- Sun the house can’t useWhen the battery is full and the panels make more than the house and the limit can take, the inverter turns the panels down. That sun is lost.
- Nothing, if export pays nothingWith no export payment, a battery has no reason to send power out, and the limit never comes into it.
On a fixed export rate, the limit was worth £27.81 in five weeks.
A real 27 kWh battery and 13 kWp of panels in the North West of England, 3 September to 7 October 2026. Its own days, with Orza planning the battery, run three ways: as if nothing held its export back, at its own limit, and held to 3.68 kW.
| Tariff | No limit | At its own limit, 6.65 kW | Held to 3.68 kW |
|---|---|---|---|
| Agile, nothing paid for export | £45.46 | £45.46 | £45.46 |
| Agile with Agile Outgoing | £9.59 | £14.17 | £19.44 |
| Agile with Outgoing Octopus, 12p | −£12.55 | £2.02 | £15.26 |
| Flux | £26.70 | £27.32 | £43.07 |
Net cost over the 34 days: what the electricity cost, less what export paid, with charge left in the battery at the end counted at what it would cost to put back. A figure below zero is money earned. Standing charges are left out. Prices are the ones Octopus published for this home’s region.
- With nothing paid for export, it made no difference£45.46 at every limit, to the penny.
- On a fixed export rate, it decided whether the home earned or paid£12.55 earned with no limit, £15.26 paid when held to 3.68 kW. Every kWh sells at the same 12p, so the only question is how many can go out.
- From 3.68 kW to this home’s own 6.65 kW was worth £13.24On the fixed rate, over five weeks of autumn. £5.27 on Agile Outgoing, £15.75 on Flux.
It is in your paperwork, your inverter, or your own readings.
You don’t need to know it to use Orza. Orza works it out from your own readings and plans every sale within it.
Three places to look
- The installation paperworkThe G98 notification or the G99 approval from your network operator states it.
- Your inverter’s settingsOften called the export limit or feed in limit, in the maker’s app or on the inverter itself.
- Your readings on a sunny dayIf export keeps stopping at the same figure while the battery is full, that figure is the limit. If it never does, the most your home has sent is the least it can send.
Before you ask for a higher limit.
One home’s five weeks of autumn are evidence, not a promise. These are the things that change the answer.
All our guidesDoes my export limit matter?
Only if you are paid for export and your battery or panels can give more than the limit. A battery of 5 kW or more on a 3.68 kW connection, or a large roof, will meet it on a paying tariff. A small system on a tariff that pays nothing for export won’t.
Can I get my limit raised?
Your installer can apply to your network operator under G99. The operator decides from the local network, so it may agree, agree to part of it, or refuse, and the application can take weeks. The figures here show what a higher limit was worth to one home, which is the question to weigh against that.
Does the limit change which export tariff is best?
It can. A fixed rate pays the same for every kWh, so it rewards sending out as much as possible, and a tight limit hurts it most. A tariff that pays most in a few hours, such as Flux in the early evening, is hurt when the limit stops a battery emptying in those hours. How the two Octopus export tariffs compared for this home.
Why is no limit shown as cheapest?
Because it is the case where nothing holds a battery back. This home’s real limit is at least 6.65 kW, the most it has been seen to send, so its own figures are the middle column. No limit is there to show what the connection is worth.
What does Orza cost?
Nothing during the beta, and no card is needed to join.
Plan every sale within your own limit, every half hour.
Free during the beta. Connect in a few minutes, and start in Monitor only.