How much will I get paid for exporting electricity?

It depends entirely on which supplier you sign up with. The Smart Export Guarantee obliges larger suppliers to offer a tariff and obliges that tariff to be above zero, and it stops there. It sets no rate, so the offers differ by a large multiple and this site will not quote a figure that would be out of date within the month. Ofgem lists the suppliers offering one.

Do I have to export to my own energy supplier?

No. Your export supplier does not have to be the one that sells you electricity, so you can shop for the export rate separately. Many people do not realise this and simply take whatever their existing supplier offers.

Is the electricity I use myself worth more than the electricity I export?

Almost always, yes, and usually by a wide margin. Using a unit yourself avoids paying the retail rate for it. Exporting it earns whatever your export tariff pays, which is typically a fraction of that. This is why the same array pays back at different speeds for two households with different daily routines.

Do I need an MCS certified installer for solar?

For the Smart Export Guarantee, yes. The installation and the installer must be certified under MCS or an equivalent accredited scheme such as Flexi-Orb. Without it you can still fit panels and still use the electricity, but you cannot claim export payments, which removes one of the four numbers below entirely.

Is there VAT on solar panels?

Not at the moment. Installation of qualifying energy saving materials in Great Britain, which includes photovoltaic panels with their cabling, control panel and inverter, is zero rated for VAT until 31 March 2027. From 1 April 2027 it reverts to the reduced rate of 5 per cent.

What actually decides whether solar panels pay for themselves

Every solar quote comes with a payback figure on it. It is arrived at by picking values for four separate things, and the person who picked them is selling you the panels.

This page is about what those four things are, so that a number somebody hands you can be interrogated rather than believed.

The four numbers

What you paid. Including scaffolding, the inverter, and any electrical work the roof needed first. Right now it also excludes VAT: installing qualifying energy saving materials in Great Britain is zero rated until 31 March 2027, after which it goes to 5 per cent. A quote that straddles that date is not quoting the same thing on either side of it.

What the system generates. A function of roof pitch, orientation, shading and where in Britain you are. Nobody can tell you this from a postcode alone, and a quote that produces a confident annual figure without having looked at the roof has estimated it.

How much of that you use yourself. This is the one that moves the answer most and the one most quotes gloss. A unit you use at the moment it is generated saves you the full retail price of a unit. A unit you export earns you the export rate, which is a fraction of that.

What you are paid for the rest. The Smart Export Guarantee.

Why self-consumption is the whole game

Two identical arrays on two identical roofs pay back at different speeds, and the difference is what time of day the household uses electricity.

Somebody at home during the day, running a washing machine at noon, heating water in the afternoon or charging a car on a sunny Saturday, is converting generation into avoided retail units. Somebody out from eight until six is exporting the middle of the day and buying it back in the evening at retail.

That is why a battery changes the arithmetic for the second household and barely moves it for the first. It is also why “how much will I save” cannot be answered without knowing when you are in.

What the Smart Export Guarantee actually guarantees

Less than people assume, and it is worth being precise, because the scheme’s name suggests a rate and it does not set one.

It obliges larger electricity suppliers to offer an export tariff, and it obliges that tariff to be above zero. That is the guarantee. The level is left to the market, so offers vary widely and change often. This site is not going to print a rate that will be wrong by the time you read it: Ofgem publishes which suppliers offer a tariff, and comparing them is a job worth an hour.

Three things about it that catch people out:

Your export supplier need not be your energy supplier. You can buy electricity from one company and sell it to another. Most people take whatever their existing supplier offers without checking.
It is metered, not estimated. Payment comes from export meter readings, so you need a meter capable of producing them.
You cannot hold it alongside Feed-in Tariff export payments. If you are on the old scheme, this is not an addition to it.

The certification catch, again

Solar under the Smart Export Guarantee requires the installation and the installer to be certified under MCS, or an equivalent accredited scheme such as Flexi-Orb.

Readers of the air conditioning grant piece will find that familiar, because the Boiler Upgrade Scheme now defines an installer the same way. MCS is quietly the gate on most of the money available to British households for energy kit, across technologies that otherwise have nothing to do with each other.

The practical consequence is the same in both cases. A competent firm without that certification can fit your equipment perfectly well and cannot get you paid. Ask before the quote, not after.

What this site will not tell you

It will not give you a payback period, a cost per kilowatt peak, or an annual generation figure.

Those exist and they are knowable, but every one of them varies by roof, region and household, and a national average presented as your answer is the exact thing this page is warning you about. The running cost calculator will tell you what a machine costs to run in pounds, which is the half of this the site can compute honestly from figures manufacturers publish.

What to do with a quote instead: ask which of the four numbers above the installer measured, and which they assumed. The answer is usually that they measured the first and assumed the other three.