Brilliant news!

[sheddi@mstdn.party]

@revk @Walrus @Edent
I'm not an electrical engineer so this might not be the whole story.

As you add generation to the local distribution network, and assuming there's not enough local demand to consume it all, the voltage rises. Eventually it gets to 258V (230+12%) which is the upper tolerance limit. At that point, local generation starts to shut down.

1/2

[sheddi@mstdn.party]

@revk @Walrus @Edent

All well and good, but folk then start to complain to their suppliers (and from there to the DNO) that, on sunny summer days, their solar inverter has shut down and they've missed out on savings/earnings.

The DNO limit / permission process is designed to keep export low enough that the local network rarely reaches 258V and they don't get deluged with complaints from their customers.

2/2

[christo_459@mastodon.me.uk]

@Edent
Not if you live on a listed residential estate

[edent@mastodon.social]

@Christo_459 You should write to your MP and assembly member to let them know your concerns.

But, it looks like you can apply for consent for a listed building.
https://historicengland.org.uk/advice/technical-advice/building-services-engineering/installing-photovoltaics/consents-permissions/

[zymurgic@mastodon.online]

@sheddi @revk @Walrus @Edent isn't that why the DNOs are currently suggesting to lower the official supply voltage in the UK to a lower voltage, to closer to the official 230v from the traditional 240v ish, to create more headroom?

[balkonsolar@freiburg.social]

@sheddi @Edent Don’t buy them at LIDL. Please not.

[christo_459@mastodon.me.uk]

@Edent
Thanks

[edent@mastodon.social]

@balkonsolar @sheddi

OK. Want to give a reason why?

[phoerious@mastodon.social]

@Edent @OneInterestingFact Plug-in solar is usually not enough that feeding into the grid is actually worth it (mostly depends on how many forms you have to fill, but you are usually also not paid enough). The main reason you want to have a solar panel on your balcony is to cover your own consumption. Add battery storage to it and you can be quite independent of the grid for a large part of the year.

[phoerious@mastodon.social]

@fishidwardrobe @Edent You plug it into your wall and it makes your meter run more slowly or in reverse. Plug-in solar inverters also often come with apps to track your production.

[inkomtech@infosec.exchange]

@Edent power / sec nerd here. How does this not energize intentionally-deenergized lines? Mustn’t cook line repair crews.

[edent@mastodon.social]

@InkomTech because an inverter matches the frequency it sees from the grid. If there's no frequency, it doesn't output.
That's how all solar inverters work.

[nowster@fedi.nowster.me.uk]

@sheddi@mstdn.party @revk@toot.me.uk @Walrus@toot.wales @Edent@mastodon.social There were mutterings recently of dropping the substation voltage to nearer the lower end of the tolerance band to accommodate more domestic PV contribution.

Nominally we are 230V but most British¹ domestic supplies are still 240V when measured.

__
¹ Northern Ireland is a separate grid and might be doing their own thing.

[xaxat@mastodon.social]

@Edent They are also making headway in the US. Now if someone would incorporate them into ventanas, roll down sunshades, used in every sunny country. You can thank me later.

[pmdj@mstdn.social]

@InkomTech @Edent Just like any grid-tied PV inverter, it constantly monitors for loss-of-main on the AC side and has to switch off within a certain number of milliseconds when cut-out is detected. This is one of many prerequisites for the device getting regulatory approval for grid connection.

[deadliftbear@mas.to]

@Edent I’ve seen these in Germany and it discombobulates me to think that I can feed electricity into my house the “wrong” way.

[pmdj@mstdn.social]

@phoerious @fishidwardrobe @Edent These things have been permitted and widely available in Austria for 5 years or so, but only if you have a smart meter (even running in "dumb" mode) which counts outflow separately from inflow. The energy suppliers don't like meters running in reverse. If you have a feed-in contract, you'll be paid for what you feed back into the grid (typically much less than energy you buy from them); if you don't, you won't.

[gundersen@mastodon.social]

@Edent this does not say of there are any requirements for the plug-in solar. The main objections here in Norway is the potential for shock from touching the prongs on the plug, from something else plugged into the same circuit and from anyone working on the main powerlines, since the panels produce power even if there is no power from the grid. Are these things considered in the UK?

[edent@mastodon.social]

@gundersen no, we just let people die.

Of course they are considered. All inverters continually check for the presence of the grid's frequency. If the frequency is lost, it immediately de-energises.

[phoerious@mastodon.social]

@pmdj @fishidwardrobe @Edent Most modern digital meters should be able to do that even if they don’t come with a smart gateway.