Balcony Solar

[Everest]

An article from The I Paper suggesting rules may be changed to allow plug in solar in the UK and available within months.

Yes, there are some upcoming changes to BS7671 (Amendment 4:2026) released next month, that will pave the way for more technical regulations, expected to be announced this summer, to permit plug in solar. There are still a lot of concerns in the industry how that will work and concerns as to how well cheap equipment may function. My concerns are regarding overloading of existing, potentially compromised circuits as well as disconnect response times for the micro-inverters as they would be connected on the load side of existing RCD protection.

On a separate note, Amendment 4:2026 is also expected to bring BSI PAS 63100 (home storage battery safety) recommendations to become mandatory after October 2026.

 

[T1 Terry]

Who will police the cheaper products are still operating as designed and the design meets the new BS rules ..... Funny that was have AS/NZS rules, but they are a lot of BS as well .....

T1 Terry

 

[NikLiverpool]

I am sensing a lot of negativity on the subject.
I am not very technical so where do these concerns derived from?
For example I saw quite a few videos where the kit was unplugged and it was not live straight a way.
Would this not help people who rent or just don't have the capital for a full solar system?

 

[Everest]

For example I saw quite a few videos where the kit was unplugged and it was not live straight a way.

Correct - that is not an area of safety concern that I am aware of.

Would this not help people who rent or just don't have the capital for a full solar system?

Absolutely - also for those that only have space for a couple of panels in the garden

I am not very technical so where do these concerns derived from?

The key concern is introducing a generation device on the load (= user) side of the existing protection devices such as MCB's or RCD's (or RCBO's). Traditionally all generation equipment should feed into the supply side.

I think I outlined most of my concern in my post #13...

Post in thread 'Balcony Solar'

Mar 13, 2026

Is the problem that you could be drawing 32amps into the ring main from the grid then adding an additional 3 from the micro inverter which would then exceed the rating of the cable but the mob wouldn't detect it?

That is my main concern, but specifically compounded by the fact that a radial circuit only needs one loose connection at one of the sockets (and I've seen that on multiple occasions) to become two radial circuits, each carrying up to 40+ Amps before any solar production is added to that, all on a single 2.5mm2 T&E cable.

There are other concerns too, such as efficacy of...

• Everest

• 

Related to that, is the additional concern as to how quickly the plug-in solar system can disconnect in the event of someone touching the live conductor of the circuit that the system is plugged into. In a standard UK house, if a person touched a live connection (due to, for example, a faulty device, or damaged cable) the RCD would trip out, typically within 40mS. Hence, in order to provide the same degree of safety, the plug in solar system would have to disconnect its supply within that time from detecting absence of the connected mains supply (note, that is only two cycles of 50Hz mains AC). Yet the technical requirements to which the devices need to adhere are yet to be defined - they are expected to be announced early summer.

 

[NikLiverpool]

Correct - that is not an area of safety concern that I am aware of.


Absolutely - also for those that only have space for a couple of panels in the garden


The key concern is introducing a generation device on the load (= user) side of the existing protection devices such as MCB's or RCD's (or RCBO's). Traditionally all generation equipment should feed into the supply side.

I think I outlined most of my concern in my post #13...

Post in thread 'Balcony Solar'

Mar 13, 2026

Is the problem that you could be drawing 32amps into the ring main from the grid then adding an additional 3 from the micro inverter which would then exceed the rating of the cable but the mob wouldn't detect it?

That is my main concern, but specifically compounded by the fact that a radial circuit only needs one loose connection at one of the sockets (and I've seen that on multiple occasions) to become two radial circuits, each carrying up to 40+ Amps before any solar production is added to that, all on a single 2.5mm2 T&E cable.

There are other concerns too, such as efficacy of...

• Everest

• 

Related to that, is the additional concern as to how quickly the plug-in solar system can disconnect in the event of someone touching the live conductor of the circuit that the system is plugged into. In a standard UK house, if a person touched a live connection (due to, for example, a faulty device, or damaged cable) the RCD would trip out, typically within 40mS. Hence, in order to provide the same degree of safety, the plug in solar system would have to disconnect its supply within that time from detecting absence of the connected mains supply (note, that is only two cycles of 50Hz mains AC). Yet the technical requirements to which the devices need to adhere are yet to be defined - they are expected to be announced early summer.

Ok this makes sense, thank you!
Playing devil's advocate though, how do they cope in Germany?

 

[Everest]

Playing devil's advocate though, how do they cope in Germany?

As you will have read in my post #9 earlier, Germany has a different domestic wiring scheme that uses radial, rather than ring, finals; thus mitigating many of the issues

 

[GaryMG4]

As you will have read in my post #9 earlier, Germany has a different domestic wiring scheme that uses radial, rather than ring, finals; thus mitigating many of the issues

I can sort of understand the issue of overloading the ring, although in my case the kitchen ring is the only one that has any significant load. I'd have to have the dishwasher, washing machine and kettle plus another device all drawing maximum load simultaneously to exceed 32amps. If I was to try this it would be plugged into the ex garden office that sits at the end of radial armoured cable so that leaves the MCB/RCDs.
My concerns are that the government will trumpet this as 'saving ordinary people money' when in reality they will spend £300-400 on something that will cover their base load for a portion of the day for part of the year. My base load sits between 100-200w, so if the house was empty for 10 hours and it covered that for the whole period it would save 50p a day.

 

[Bam Bam]

I can sort of understand the issue of overloading the ring, although in my case the kitchen ring is the only one that has any significant load. I'd have to have the dishwasher, washing machine and kettle plus another device all drawing maximum load simultaneously to exceed 32amps. If I was to try this it would be plugged into the ex garden office that sits at the end of radial armoured cable so that leaves the MCB/RCDs.
My concerns are that the government will trumpet this as 'saving ordinary people money' when in reality they will spend £300-400 on something that will cover their base load for a portion of the day for part of the year. My base load sits between 100-200w, so if the house was empty for 10 hours and it covered that for the whole period it would save 50p a day.

1. At current prices? Or future prices if Trump and Iran keep playing silly buggers?
2. Will the units come with little batteries that would extend this period? Eco-flow are a battery company so I expect that is what they will be selling but I don't know what the most common equipment will end up being.

 

[Bam Bam]

I am sensing a lot of negativity on the subject.
I am not very technical so where do these concerns derived from?
For example I saw quite a few videos where the kit was unplugged and it was not live straight a way.
Would this not help people who rent or just don't have the capital for a full solar system?

Indeed, that is what has happened in Germany.

Would be great to have something similar here.

Though there are differences between the countries.

Germany has more renters, more people live in flats/apartments and they have electrical systems that are more suitable (as Everest has been mentioning).

 

[johnb80]

Oh Dear the UK. I am surprised you are allowed to fit a three pin plug.

A lot of our rules and regulations are thanks to the EU, so not sure why youre surprised.

 

[johnb80]

It does sound great, hang a couple of panels on your balcony, plug in to a socket and away you go saving a fortune except........ it wont.
1) The panels wont be at the best angles to the sun, I know they only need daylight but if they're ever to meet their rating it needs to be perfect angle and bright sunshine.
2) At best from a couple of panels you will see a peak of around 50% ish of their rating, as soon as you're before / after midday that will plummet.
3) Plugging into a 13amp socket on the wrong side of an RCD sounds alarm bells for me.
4) Just imagine the turmoil from flying panels when it get windy.
5) I seriously doubt the bang per buck on this type of setup.

Do it right or dont do it.

 

[GaryMG4]

1. At current prices? Or future prices if Trump and Iran keep playing silly buggers?
2. Will the units come with little batteries that would extend this period? Eco-flow are a battery company so I expect that is what they will be selling but I don't know what the most common equipment will end up being.

If it carries on too long I expect there will be pressure to decouple electricity prices from gas, plus there will be a lot of other inflationary pressures.
I think you are looking well north of £1k for Ecoflow Stream system, but yes a battery would increase the savings.

 

[Bam Bam]

If it carries on too long I expect there will be pressure to decouple electricity prices from gas, plus there will be a lot of other inflationary pressures.
I think you are looking well north of £1k for Ecoflow Stream system, but yes a battery would increase the savings.

good point - I saw an ecoflow balcony system for about £1,800. The battery would be useful, but you probably don't get a huge capacity with these systems.

 

[GaryMG4]

good point - I saw an ecoflow balcony system for about £1,800. The battery would be useful, but you probably don't get a huge capacity with these systems.

The £1800 (non sale price) has a massive 1.92kWh battery, although the sale price is currently £1200. Like Oak Furnitureland there's nearly always a sale on! Just shy of £3k for a 7.6 kWh setup, although you are still limited to 800w grid tied and 2.2Kw for the 3 pin sockets.

 

[NikLiverpool]

Well in my case I already have a 7,28kw roof system and 3 power walls. My problem though is that due to the house orientation the kit is not fully optimised.
Two to four more panels on my shed though in theory could cover the gap I am currently having and support my heat pump during some of the late autumn, early spring days...
I will be keeping an eye on the developments.

 

[Bam Bam]

Well in my case I already have a 7,28kw roof system and 3 power walls. My problem though is that due to the house orientation the kit is not fully optimised.
Two to four more panels on my shed though in theory could cover the gap I am currently having and support my heat pump during some of the late autumn, early spring days...
I will be keeping an eye on the developments.

Similar to us in that we have East-West roof with solar and have now added a heat pump.

Some extra solar would now really help!

Eyeing up the South-wall, South-facing fence and west-facing garage roof.

Pebbles might not think it is a good investment, though!