How to check a kit has actually been tested

Ask the seller for the kit's reference number, then look it up. It takes about thirty seconds and it is the single most useful thing you can do before buying.

Anything that feeds electricity back into the wires outside your house has to be tested in a lab first. The results go on a public list. If a kit is on that list, someone independent has checked it behaves safely; if a seller cannot tell you where their kit is on it, that is worth knowing before you hand over £600.

Almost no seller's page explains any of this, so here is the whole thing: what the test is for, what the list is, and how to use it.

Who keeps the list

The companies that own the cables in your street — not the company that bills you — have a trade body, the Energy Networks Association. It writes the engineering rules for anything that connects to those cables, and it publishes the list of equipment that has been tested against them.

What the test is actually checking

The one that matters most is this. Picture an engineer working on a cable they have been told is dead, because the substation feeding it has been switched off. If the box in your kit carried on pushing electricity backwards into that cable, it would keep the line live and the engineer would have no way of knowing. So every device has to detect that the power has gone out and disconnect itself immediately.

That is the test that matters, and the engineers' name for it is anti-islanding. The wider set of safety rules it belongs to — the ones for anything small enough to plug in that feeds electricity back into the network — is called G98. A device that has not been through that testing in a lab is not something anyone should have connected to the network, plug-in or otherwise.

What the register actually is

Devices that have been through this testing process are published on the ENA's Connect Direct register, at connect-direct.energynetworks.org. This is the current, live register.

It moved. An older register at ena-eng.org was the reference point before April 2024, when it closed. Any advice, forum post, or seller page that still points you to ena-eng.org is out of date — it is not being maintained and should not be treated as current.

At the time of writing, filtering the Connect Direct register to device type "Plug-in Solar" returns 31 devices. Each entry records a manufacturer, a model number, a registered AC capacity, which type tests it has passed, and a compliance status.

The reference number, and how to use it

Every device on the list has a reference number that looks like this: UKSOL/21008/V1/A4, or PERLI/21158/V1. The maker's name, a serial number, a version. That is the thing to ask a seller for — not the product's marketing name, which often does not match what was actually tested. Its proper name is the System Reference, and nobody in the shops uses that phrase, which is exactly why asking for it gets you a straight answer.

With the reference in hand, you can search the register yourself and confirm: who registered it, what AC capacity it is rated at, and which type tests it has passed. This takes under a minute and is the single most useful check a buyer can do.

The trap: the whole kit, or just the box inside it

Some entries on the register are complete kits, registered by the retailer selling them. Others are individual inverters, registered separately by their manufacturer, and sold on inside kits assembled by other companies.

This distinction matters because a seller can honestly say "the inverter in this kit is G98 registered" while the kit itself, as assembled and sold, has never been tested or registered as a unit. Whether that is a meaningful difference depends on how the kit is built — but as a buyer, you want to know which situation you are in, and a seller quoting you an inverter's registration when you asked about the kit is not answering the question you asked.

On the list, but not accepted: the bit almost nobody explains

Every entry on the register carries a device status, and until 29 August 2026 we declined to publish it because we could not establish what it recorded. We can now, because ENA say so themselves, on each device's own page, under a heading noting that the status is "assigned by ENA appointed evaluators":

Compliant — "This device has been assessed by ENA's engineers and has been deemed acceptable for use by Distribution network operators"

Non-compliant — "This device has been assessed by ENA's engineers as non-compliant. Distribution network operators are unlikely to accept this equipment on their networks"

Across the whole register, 1,514 of 9,279 devices currently carry the non-compliant status.

Read what that says, and not more than it says. Three things follow, and all three matter:

It is ENA's assessment, not a test result. Every device on the register — including every one marked non-compliant — shows a completed full G98 type test. The status is a human evaluation sitting on top of the test data, which is why the two can differ. Passing the test and having the submission accepted are two separate steps, and the register reports the second.
It is not a statement that anything is illegal. ENA's claim is specific and narrower than that: distribution network operators are unlikely to accept the equipment on their networks. That is a meaningful thing to know before you buy a device you will then have to notify your network operator about. It is not a ban, and we will not render it as one.
It moves. One manufacturer's status changed within days of being listed. Any status we show carries the date we checked it, and every device page links through to ENA's own entry so you can see today's value for yourself.

It is ENA's assessment throughout. We report it, we do not make it, and it is not our verdict on anybody's product.

How to use this in practice

Get the seller's System Reference for the specific product, not the inverter inside it, unless that is genuinely what you are buying.
Search it on Connect Direct yourself.
Confirm the registered AC capacity is 800W or below.
Confirm FTT_G98 (full type test, G98) shows as passed.
If anything does not match what you were told, ask the seller to explain the discrepancy before you buy.