Will SEG export rates fall? What more UK solar means for what you get paid

There's a question doing the rounds among people who already have solar, and it's a good one: if everyone keeps installing panels, how long can suppliers keep paying 10–15p a unit for power exported in the middle of a sunny day — exactly when the grid least needs it?

The worry is reasonable. Some homeowners are already running the arbitrage play: export everything the panels make at a high Smart Export Guarantee (SEG) rate, and charge the battery overnight on cheap off-peak import instead. It works beautifully today. The question is whether it's a window that's quietly closing.

This guide is an honest look at where export rates might go, why, and what it means for a system you're buying now. We're not predicting a number — nobody credibly can. We're laying out the forces so you can design around them.

Why the worry is well-founded

The logic is sound, and it's worth stating plainly.

Solar all generates at the same time. On a clear June afternoon, every panel in the country is pushing power at once, into a grid whose demand hasn't moved to match. When supply outstrips demand, the wholesale price of electricity falls — and at extremes, it goes negative, meaning generators pay to offload power. In Great Britain this already happens: spring and summer middays increasingly see wholesale prices drop near zero or below for a few hours.

SEG export tariffs come in two flavours, and they react differently:

• Fixed export rates (a flat 12p, 15p, etc.) are a commercial offer. A supplier pays it because exported solar is cheaper than buying wholesale — for now. If midday wholesale prices keep falling, the fixed rate that made sense in 2025 stops making sense, and the supplier quietly retires it for new customers.
• Tracking export rates (Octopus Agile Outgoing and similar) follow the wholesale price by the half-hour. They already pay 20p+ at peak and can drop to near-zero — or negative — at midday oversupply. They don't need to be "cut"; they just reflect reality as it shifts.

So the mechanism the original poster is worried about isn't hypothetical. It's how the system is built to behave. The only question is the pace.

The signs it's already starting

A few data points suggest the squeeze isn't years away — it's begun.

• Headline fixed rates are softening on renewal. Homeowners are reporting export rates dropping sharply when an introductory deal ends — in some cases from the mid-teens down to single digits unless they bundle in the supplier's import tariff too.
• Premium rates increasingly come with strings. The best export tariffs are more and more often only available if you also take the supplier's import tariff, or run a smart meter sending half-hourly data. The standalone "just pay me 15p for my export" offer is getting rarer.
• Suppliers are buying export at a loss as a customer-acquisition tool. A generous export rate is a cheap way to win a household's whole energy account. That's a marketing budget, not a permanent economic fact — and marketing budgets get cut.

None of this means rates collapse next quarter. It means the direction of travel on the high fixed rates is down, and the homeowners feeling it first are the ones coming off introductory deals.

The forces pushing the other way

Here's where the honest version diverges from the doom version. The "rates go to zero" story assumes supply keeps rising while demand sits still. Demand is not sitting still.

• Electrification is ramping hard. EVs, heat pumps, and the general shift off gas all add electricity demand — much of it shiftable to soak up cheap daytime power. An EV charging at midday is, in effect, a household consuming its own and its neighbours' solar surplus.
• Data centres are a genuine new load. The build-out of AI and cloud infrastructure is adding industrial-scale demand to the grid, some of it deliberately sited and timed to use cheap renewable power.
• Storage is scaling at every level. Grid batteries, home batteries, and EVs are increasingly able to absorb midday surplus and release it in the evening peak. The more storage there is, the less often midday prices crater — because something is there to buy the cheap power.

The future isn't simply "solar floods the grid and the price falls forever". It's a race between how fast generation grows and how fast flexible demand and storage grow to meet it. Midday power becomes cheap, yes — but cheap power tends to find new uses.

The Australia comparison — useful, but not a prophecy

Australia comes up a lot, and for good reason: it's further down this road. High rooftop-solar penetration there has pushed feed-in tariffs down dramatically, and some networks have introduced two-way tariffs — charging households for exporting during the sunniest, most congested hours. The lesson people draw is "minimal export rates, penalties at peak sun, and the real money is in a Virtual Power Plant".

It's a fair signpost, but two caveats matter:

• The UK isn't Australia. Different climate, different generation mix, far less midday solar dominance, a colder evening peak, and a faster heat-pump and EV ramp pulling demand the other way. The destination may rhyme; the timing and severity needn't match.
• "The grid stops valuing dumb export" is not "solar stops paying". What Australia really shows is that the value moves — from exporting whenever, to exporting when it's needed, and to using or storing your own power the rest of the time. That's a design change, not a death sentence.

What this actually means for a system you buy now

Here's the practical core. If export rates are the uncertain part of the equation, the resilient move is to lean on the part you control: self-consumption.

Solar's financial case rests on three levers, and they don't carry equal risk:

1. The grid electricity you avoid by using your own generation. This is the safe lever — it's worth your import rate (27–32p/kWh in 2026), and if anything that's been trending up. See rising energy costs and solar.
2. What you're paid to export the surplus. This is the at-risk lever — the one this whole guide is about.
3. The fixed upfront cost. Known the day you buy.

A system designed to export as much as possible is betting on lever 2 holding up. A system designed to use as much as possible — sized to your actual consumption, with a battery to shift daytime surplus into the evening — leans on lever 1, the durable one. Export then becomes upside, not the foundation of the payback.

That reframing also rehabilitates the overnight-arbitrage play. Charging a battery on cheap off-peak import and using it at peak doesn't depend on a high export rate at all — it depends on the gap between peak and off-peak import prices, which time-of-use tariffs are widening, not narrowing. See the Octopus Go and time-of-use guide for how that maths works.

And the emerging answer to "where's the value if not dumb export?" is flexibility: Virtual Power Plants and smart export tariffs that pay you more for sending power at the right moment and storing it the rest of the time. The household that can choose when to export is worth more to the grid than the one that exports on the sun's schedule — and increasingly gets paid for it.

How to stress-test your own numbers

You don't need to guess the future export rate. You need to know whether your case still works if it falls. The savings calculator lets you do exactly that:

• Run it once at today's export rate, then again at half that. If the payback only moves by a year or two, your case is built on self-consumption and is robust. If it falls apart, you were relying on export — and that's the assumption worth de-risking with a battery or a smaller, better-matched system.
• Check what share of your generation you'd actually use versus export. A household that's out all day and exports most of its solar is far more exposed to a rate cut than one that's home, drives an EV, or runs a heat pump.

If you're at the start of this and don't yet know your roof's shape, the roof check gives you direction, rough system size, and a benefit range for your postcode in about a minute — the inputs you need before any of this maths means anything.

The honest verdict

Will SEG export rates fall? On the high fixed tariffs, the pressure is real and the direction looks down — the arbitrage window that pays 15p for midday export probably does narrow over the next few years. But "export pays less" is not "solar stops paying", and the people forecasting zero are quietly assuming demand and storage stand still while generation races ahead. They won't.

The sensible response isn't to abandon solar or to panic about a rate that might change. It's to design for the world that's clearly coming: size the system for what you actually use, add storage if the numbers support it, and treat export as the upside rather than the plan. A system built that way doesn't much care which way export rates break — and a system built on today's export rate surviving forever is the one that gets caught out.

That's the real shift the Australia-watchers are pointing at. Not the end of solar economics — the end of lazy solar economics.

Related

• Smart Export Guarantee (SEG) — how UK solar exports actually pay
• Solar with Octopus Go and time-of-use tariffs
• Rising UK energy costs and solar — does the case actually change?
• Solar battery storage UK — worth it in 2026?
• Use the savings calculator