Solar ... In the news

QrizB

Sorry, this isn't really "news" but I think it's a logical place to put it?

QrizB said:

Germany's approach is to limit you to (link) 800 watts of balcony PV, which is only 4 amps or so.

Edit: here's a self-install kit, 800 watt inverter plus 900 watts of panel for £300:

https://www.ebay.co.uk/itm/134766303393

International shipping from Germany is a bit of a sting, at ~£100 if you wanted one delivered to the UK, but it show's what's possible when there's a market.

You might remember the link above that I shared in February? It's still available, but right now there's a similar kit from EcoFlow being sold into the UK, including UK delivery for £389 - currently discounted to £314 with a code as there's an eBay promotion on.

https://www.ebay.co.uk/itm/316834628681

I seem to recall these come with instructions that the final connection should be made by a qualified electrician but there's nothing actually stopping you from plugging it in ...

QrizB

It's me again.

I was just thinking to myself about that 800 watt system while cleaning the house (not all of it!).

Let's say it makes 800 kWh a year. Self-installed you won't qualify for an export tariff but even so, if it's the only PV you've got you'll probably be able to self-consume 50% of its generation? So 400kWh at 25p/kWh - that's £100 a year, a payback period of a touch over three years.

At 40% you're saving £80 a year and payback is four years. At 30% (typical for larger systems), £60 a year and payback in five-ish years.

Martyn1981

QrizB said:

It's me again.

I was just thinking to myself about that 800 watt system while cleaning the house (not all of it!).

Let's say it makes 800 kWh a year. Self-installed you won't qualify for an export tariff but even so, if it's the only PV you've got you'll probably be able to self-consume 50% of its generation? So 400kWh at 25p/kWh - that's £100 a year, a payback period of a touch over three years.

At 40% you're saving £80 a year and payback is four years. At 30% (typical for larger systems), £60 a year and payback in five-ish years.

*Pedant alert* ...... sorry.

Tiny bit of number polishing, since these are typically installed vertically, the annual generation will be lower, probably around 650kWh or so?

But, and it's a big butt. Vertical will reduce summer gen, so less excess export, and boost winter gen, when it'll all be consumed. So your 400kWh consumption is still fair and reasonable, in my opinion.

Magnitio

QrizB said:

It's me again.

I was just thinking to myself about that 800 watt system while cleaning the house (not all of it!).

Let's say it makes 800 kWh a year. Self-installed you won't qualify for an export tariff but even so, if it's the only PV you've got you'll probably be able to self-consume 50% of its generation? So 400kWh at 25p/kWh - that's £100 a year, a payback period of a touch over three years.

At 40% you're saving £80 a year and payback is four years. At 30% (typical for larger systems), £60 a year and payback in five-ish years.

If you added it to a house that already has PV, would you be in breach of your agreement with the DNO?

QrizB

Magnitio said:

QrizB said:

It's me again.

I was just thinking to myself about that 800 watt system while cleaning the house (not all of it!).

Let's say it makes 800 kWh a year. Self-installed you won't qualify for an export tariff but even so, if it's the only PV you've got you'll probably be able to self-consume 50% of its generation? So 400kWh at 25p/kWh - that's £100 a year, a payback period of a touch over three years.

At 40% you're saving £80 a year and payback is four years. At 30% (typical for larger systems), £60 a year and payback in five-ish years.

If you added it to a house that already has PV, would you be in breach of your agreement with the DNO?

I think that, if your current system is less than 2.88kW, you could add another 800 watts and still come in under the G98 3.68kW limit (so you'd need to notify the DNO but they're unlikely to object).

If your existing system uses more than that, you'll need to make a G99 application first.

But I'm not a MCS-accredited installer so don't trust me on this (or anything else).

Coastalwatch

QrizB said:

Magnitio said:

QrizB said:

It's me again.

I was just thinking to myself about that 800 watt system while cleaning the house (not all of it!).

Let's say it makes 800 kWh a year. Self-installed you won't qualify for an export tariff but even so, if it's the only PV you've got you'll probably be able to self-consume 50% of its generation? So 400kWh at 25p/kWh - that's £100 a year, a payback period of a touch over three years.

At 40% you're saving £80 a year and payback is four years. At 30% (typical for larger systems), £60 a year and payback in five-ish years.

If you added it to a house that already has PV, would you be in breach of your agreement with the DNO?

I think that, if your current system is less than 2.88kW, you could add another 800 watts and still come in under the G98 3.68kW limit (so you'd need to notify the DNO but they're unlikely to object).

If your existing system uses more than that, you'll need to make a G99 application first.

But I'm not a MCS-accredited installer so don't trust me on this (or anything else).

That's an interesting question as I had previously considered placing 3 panels on our garden shed but adding them required a minimum of thirty metres of DC cable adding to the overall cost making it barely worth the effort so decided not to pursue. With the system QrizB has highlighted could I dispense with DC cabling and simply plug into one of the sockets in the shed. Then remembered existing system is 8.85kWp(8.26 SSE facing 23 degree pitch and 0.59 WNW vertically mounted) with 6kW inverter automatically capped at that figure. According to SE datasheet Inverter is rated to a maximum of 9.3 kWs DC so possibly approaching that in ideal conditions. The shed also faces SSE so these panels would make total here 9.06 kW's although WNW panels wouldn't add any credible power until 2pm by which time the sun is past it's peak on SSE so might possibly be ok.

While we have G100 compliance with permission to export 12kWs it would seem our Inverter places a question mark on this uprated system too!

Martyn1981

Hi CW, be careful I would suggest. Remember that the plug n play systems are not approved for the UK, so they have to be hardwired to the CU, or on a cicuit with no other sockets/devices, which is pretty much the same thing.

Personally (don't quote me) I suspect these things are fine and great, but I'd be concerned about voiding home insurance, for a totally un related event, if someone found out.

I assume it would be fine to connect these directly to a DC battery, if it has PV connection, as that would be behind the main inverter which has been certified and DNO approved. Perhaps, but not cheap, you coould connect panels to a powerstation, and then run one of your A2A units off that battery, as you would be by-passing the grid. You could also then in winter, charge that powerstation from the mains, if you wanted too.

Hopefully my understanding is still up to date for the UK, but I remain positive that it will change, so maybe something has?

Coastalwatch

Thanks Mart, appreciate your thoughts and concerns as it certainly wouldn't do to risk voiding the home insurance. I hadn't considered that other than warranty on Inverter. For the output of just two panels it hardly seems worth the endeavour. 

Something else that crossed my mind, albeit fleetingly, was a car port to keep the EV's cooler in summer which then gives rise to adding a fair array of panels on the roof, circa 6 x 6 metres worth but really unsure of a sensible design in the front of our property and wouldn't want to add something akin to a carbunckle. Could possibly consider a shallow apex E/W or SSE flat roof with a shallow south facing pitch. Perhaps neither being ideal on north side of bungalow but something to contemplate given the possibility and presumably linked to a battery DC wise as I believe you suggest might be required.

Day dreaming again!. 

QrizB

Seems like plug-in solar might come to the UK after all:

https://www.theguardian.com/business/2025/jun/30/britons-could-soon-install-balcony-solar-panels-in-flats-and-rental-homes

That EcoFlow bundle is back on eBay, 800 watts for £314 with another of those coupon deals ...

Edit: I see Martyn posted the same article on the "battery" thread, and beat me by 6 hours or so!

Martyn1981

Hi QrizB, you really got me thinking the last few days, about that Ecoflow bi-directional powerstation, especially given the recent news on a potential slackening of UK rules to allow 'balcony solar'.

This is pure conjecture from me, and almost certainly a co-incidence, but given that Germany has an upto 800W AC side allowance for these small PV systems to be plug n play ....... I noticed that the Ecoflow battery you mentioned, which is designed to work with small PV systems, is also 800W AC.

Again, this is all based on what changes are made, if any, and what power limits are allowed, but a relatively cheap PV and battery system might be possible (for almost everyone), and DIY going forward. [And even if not 800W, I'm sure UK specific products will evolve.]

Just for reference here's the UK's action table, with plug in solar at item 2.