Plug in solar

Qyburn

https://forums.moneysavingexpert.com/discussion/comment/81923803#Comment_81923803

The sticking point with current regulations is that any generation needs to be connected on the supply side of any circuits serving loads. That's why if these are changed to allow connection to a general purpose circuit, there would probably be quite a low power limit.

Regarding the "prongs live" issue I think current 13A plugs with the part insuinsulated prongs disconnect before they're pulled out far enough that the brass is exposed. But I don't know how quickly the inverter shuts down on loss of AC.

RCD between the supply and the inverter needs to be bidirectional so that it's not liable to damage if powered from the "wrong side" when tripped. And whatever device actually protects the circuit should switch both L and N.

QrizB

In the context of the "live prongs" concern, the extant UK G98 standard for grid-tied inverters requires that inverters disconnect+shut down) within 0.5 seconds in the event of grid frequency or voltage deviating from the normal range.

This would include unplugging an inverter.

See paras 10.1.3 and 10.1.4 of Engineering Recommendation G98.

Vitor

Britain is so risk averse, like no sockets in bathrooms, it seems incredibly unlikely they'll OK plug-in solar using standard 13A plugs. Will probably mandate shielded and keyed plugs.

prowla

I saw a YT video on this; though the item has an exposed 13A plug, it has a sensor which requires it to be plugged in to a wall socket before it supplies power (the person touched the plug pins to confirm).

Nonetheless, it feels wrong to have powered plugs (not sockets) and some years ago I had an incident where a stage technician had wired a live plug and an incident occurred. It also relies on the service's control circuitry being 100% reliable.

QrizB

Per Ed Milliband's column in the Observer:

https://observer.co.uk/news/opinion-and-ideas/article/ed-miliband-our-mission-is-to-drive-for-clean-homegrown-energy-we-can-control

We’re also speeding up the availability of “plug-in solar” to the UK. These are small solar panels you can buy in a supermarket and put on your garden or balcony. They are already wildly popular in Germany, and we will work with supermarkets and retailers to make them available here.

That sounds very much like self-installation following the German model.

Reed_Richards

I wondered for a minute if such a plug solar system could run in conjunction with my existing solar panels. Under the FIT scheme I am paid for generation but the generation meter is on the feed from my existing panels so would not record any additional generation. I would be able to export a bit more electricity; these days I am paid for actual export but I don't see that a bit more actual export would be an issue for payments. But how would my inverter react if the current clamp measuring export saw more export than the inverter knew it was providing?

Martyn1981

https://forums.moneysavingexpert.com/discussion/comment/81923652#Comment_81923652

Yes, and there's the possibility to install more than that in PV capacity, as it's the circuit feed-in that is limited to 800W. So 1kWp of PV or 1.2kWp as you suggest, running through a micro-inverter rated for that input and with an 800W output.

But wait …. there's more …. you can go one step further and include a hybrid (two way) inverter powerstation, such as the Ecoflow Stream series. They can store cheap leccy from the grid, and more than 800W input of leccy from PV, but limit feed back to the 800W (or lower) figure.

The Ecoflow 4kWh model, the Ultra X, has 4 MPPT feed ins for PV, can handle up to 2kWp of PV, and when bought as a package, also tends to come with a demand monitoring device. If used, this can keep on eye on grid import and export, and adjust the power flow from the battery accordingly, again upto the 800W limit.

Whilst balconies are perfect, and brackets will allow panels to have a mild slope to improve generation, these plug-in-PV kits will also work really well mounted on a south facing fence or wall. DIY solar, and potentially DIY storage too.

Aussie_Tips

This needs a lot more thought before any action is taken. In Germany, the rules for balcony solar are already strict. A maximum of 800 watts may be returned and special sockets are required

In the Netherland there are concerns as there are no limits on installed capacity

https://ioplus.nl/en/posts/beware-plug-in-balcony-solar-panels-are-risky

Scot_39

Silly question - but is there any way these plug in solar can operate into restricted rather than live - when its otherwise dead / or only when live - to share the load a bit.

(On E10 theirs a restricted slot 1-4pm - peak solar gen time ? But now only 1 of my low powered heaters is only on about 1→1.5 hours of that 3 hrs - the bigger less than 1/2 hr and the HW 15-20mins) - so not sure worth it.

I presume they are only single output - so cannot drive into both live and restricted in parallel ?

Given that's not on the same meter feed/ home circuits as ring main.

Apart from shower and cooking / washing etc for 5-10-20min my load is seldom much more than 2-300 Watts. More often c100W during the day max if out. So seems the excess may be wasted without a battery to time shift

QrizB

Silly question - but is there any way these plug in solar can operate into restricted rather than live - when its otherwise dead / or only when live - to share the load a bit.

There are no silly questions! (Ok there probably are, but that isn't one.)

The sort of inverter that these systems use will only output power when there's a live grid connection. In principle you could connect it to the restricted circuits of an E7 / E10 supply, but you'd only get output when that supply is live and the sun is up.

Better to connect it to a permanently live circuit and get the benefit of offsetting (all or part of) your base load during all daylight hours.