Plug In Solar consultation now open

[flameport]

Documents here, published today 16 June 2026: https://www.gov.uk/government/consultations/plug-in-solar
including the interim product specification for the equipment.

Only a measly 2 weeks to respond, closes 30 June 2026.

 

[mattylad]

No point responding, they are not going to take the blindest bit of notice of anything the public say and will just go ahead as long as they get their bit of tax from the scheme.

 

[Murdochcat]

How ridiculous. As abovv no point in responding as they never listen

 

[ericmark]

Well it tells us some things

5.7 Influence of residual current devices (RCDs)
Plug‑in solar shall comply with the requirements relating to DC residual current components in accordance with BS EN 62109‑1, Clause 7.3.8.
The device shall be designed such that it does not adversely affect the operation of upstream residual current devices.

Not sure how that will be done?

800 VA maximum export (3.5 amps) and 2000 watt maximum panel size.

Non-rewireable moulded plug fitted with a BS 1362 fuse not exceeding 5A; half-insulated pins.

No battery permitted.

G98 will be required. Likely will not be paid for export, only quick scan through the documents.

Where the consumer unit does not use modern protective devices, is not clearly labelled, or is of unknown condition, users shall be advised to seek inspection and assessment by a qualified electrician before installing the product.

If the electrical installation is using older fuse protection and does not incorporate RCBOs, the installation shall be checked and, where necessary, upgraded by a professional electrician;

Plug‑in solar shall comply with the requirements relating to DC residual current components in accordance with BS EN 62109‑1, Clause 7.3.8.
The device shall be designed such that it does not adversely affect the operation of upstream residual current devices.

So it would seem only true plug in solar if the consumer unit has Type A RCBOs otherwise an electrician required, but we have already shown not all Type A RCBOs are bidirectional, efixx seem to think it does not require bidirectional, but in the main we still have the same question, how to ensure the RCBO is bidirectional?

It also seems to say an amendment to BS7671 will be required, but the last one has still not come into force yet.

The bit I can't understand, if plug and play, how will the G98 work as the device is moved from property to property? It seems to be saying needs an electric meter which can measure in ½ hour slots, so also will need a smart meter to be able to use it.

However, only scanned through the document quickly, I may have missed something. As to the panels, with no battery, in my home around 300 watt would be the limit as far as self consumption, although I do use over that at times, the time it is used for is short, as without a battery the whole solar array can only really help when just covering back-ground use.

I also note the requirement to be type tested, so any units already sold will still be illegal to use.

 

[JohnW2]

Well it tells us some things

.... The device shall be designed such that it does not adversely affect the operation of upstream residual current devices.

In the case of 'plug-in solar' (or any other sort of local generation) with a grid connection, which direction is "upstream"?

 

[ericmark]

which direction is "upstream"?

Good point, but we have talked about plug in solar a lot since March, and only point which seems to be a problem in real terms is unidirectional devices, which seems to be the RCBO, and there are type A RCBOs which are unidirectional, and they have no marking to tell anyone is unidirectional or bidirectional without removing the CU cover. The rest seems to be covered.

Even the trip time, it seems less than 40 mS for loss of supply, but more time for when the supply is only reduced to reduced low voltage, although that does seem to be an odd way of putting it.

 

[JohnW2]

Good point, but we have talked about plug in solar a lot since March, and only point which seems to be a problem in real terms is unidirectional devices ...

... and I'm personally not even convinced that that is a significant problem, nor am I convinced that there are (m)any 'unidirectional' devices in service.

 

[ericmark]

... and I'm personally not even convinced that that is a significant problem, nor am I convinced that there are (m)any 'unidirectional' devices in service.

I see your point, even efixx seemed they could not make their mind up.

 

[JohnW2]

I see your point, even efixx seemed they could not make their mind up.

As you've pointed out, they certainly seem to have demonstrated that there is a potential problem relating to the test button, but I am personally far from convinced (indeed, am pretty doubtful) that there is any potential problem other than the test button one.

 

[ericmark]

I suppose if pressing the test button causes it to fail, then it is in a household where the test button is used, so they will know that the device has failed reasonably soon after the event.

 

[JohnW2]

I suppose if pressing the test button causes it to fail, then it is in a household where the test button is used, so they will know that the device has failed reasonably soon after the event.

True. However, I suspect what we saw in that video was an extremely rare event, with the electronics of the device having been (one imagines thermally) damaged when the test button was pressed. I would have expect that, in virtually all cases, what would 'fail' (if anything) would be the test button resistor (hence test button functionality), with the device itself not 'failing at all'. Of course, when the terst button was next pressed, the device would fail to trip, even though it (the device) was still working fine - but that's a problem in the good direction, sincethe device would hopefully be replaced because it didn't respond to the test button, even if 'proper testing' indicated that it was still working fine!!

As I've said before, it would seem that an inevitable 'test button problem' (overheating/destruction of test resistor) can arise (with either a unidirectional or bidirectional RCD) if (due to an RCD fault/stiction/whatever) the device fails to trip when the button is pressed (for an appreciable period of time) - but the device would presumably then be changed, anyway, regardless of whether or not the test resistor had 'burned out'.

 

[ericmark]

It does seem, what ever we think, that plug and play will be allowed, the only problem seems to be if the test button is pressed, but to instruct users not to press the test button still seems wrong.

OK I don't use the test button, I have a tester, so I would never press the test button as for me there is no point, but I would think I am unusual to have a proper RCD tester.

Also for me, if my RCBO fails, it is easy for me to get a replacement, but with older consumer units, new replacements may not be available. Or very expensive. To advise getting an electrician would seem to be a little late, once some has bought a solar array opened it and read the instructions it is a bit late to tell them sorry you need a new consumer unit before you can use it raising the price by a factor of four.