Wanting a home solar system in Yorkshire, UK

[mtdoc]

A grid tie inverter is tied to the grid so that it can track it's voltage, no grid voltage  = no output as there is no line voltage to track, even your £50 crap from china does that as it's fundamental principle of operation of a grid tie inverter.

Yes, but there are also "grid interactive" inverters which tie to the grid but also work as off-grid inverters running off of batteries when the grid goes down.

There are also "AC coupled" inverters (see here for more detail) which are able to supply AC power direct from standard grid tie only inverters - even in a grid outage - by coupling into a battery based system.

In addition, I believe SMA has a product out now that allows you to tap directly into some of your grid-tie only PV production during a power outage - without batteries.

In the USA all grid tie or grid interactive inverters are required to meet UL 1741 anti-islanding requirements to ensure safety of utility workers.

[james_s]

A friend of mine who lives in Manchester has had a 4kW PV array for quite a while now, around 10 years I think. I don't know who installed it but it was professionally done and has long since paid for itself. I would guess this stuff has only become more economical in the meantime.

[Monkeh]

I had a rather unhappy encounter with around 600VDC coming out of my grid-tie inverter with the main switch off. They'll bite you. Isolators are not optional.

And no, it's not some cheap thing out of China, it's a Fronius IG TL.

[moz]

I built my own 12V PWM charge controller from scratch. You're welcome to the design

Thanks, but I've already got my BoM ordered and mostly delivered. Although thinking about it, the step from a ridiculously overpowered Arduino just logging power to also doing full charge control is, as you say, not a lot of components. I might get back to you on that.

[Someone]

So, if an electrician/handyman needs to work on, say, a socket, they will disconnect the mains supply by the switches in the fusebox. They will assume the circuits are dead.

At that point, is the electricity disconnected, or are the circuits still live with potentially lethal voltages/currents?

The inverter is simply plugged into the wall but as far as i know a proper grid tie inverter that this is has to go dead if no "line" voltage is detected. A full blown installation may have it permanently wired in with a double pole isolator, either way an electrician still needs to be aware of the existence of a solar system.

If I understand you, it sounds like you are "driving a mains plug in reverse".

That and the grids are getting much better at providing diagnostics (automatically and without humans) so if you keep dumping power into the mains the grid operator will notice sooner or later, much sooner if you have a smart meter lol. Not worth the risk when you see the fines possible.

[Simon]

So, if an electrician/handyman needs to work on, say, a socket, they will disconnect the mains supply by the switches in the fusebox. They will assume the circuits are dead.

At that point, is the electricity disconnected, or are the circuits still live with potentially lethal voltages/currents?

The inverter is simply plugged into the wall but as far as i know a proper grid tie inverter that this is has to go dead if no "line" voltage is detected. A full blown installation may have it permanently wired in with a double pole isolator, either way an electrician still needs to be aware of the existence of a solar system.

If I understand you, it sounds like you are "driving a mains plug in reverse".

That and the grids are getting much better at providing diagnostics (automatically and without humans) so if you keep dumping power into the mains the grid operator will notice sooner or later, much sooner if you have a smart meter lol. Not worth the risk when you see the fines possible.

When i asked they said if the unit is CE marked they don't have a problem. I asked my current provider about feed in tariff and they don't seem bothered.

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[tggzzz]

If I understand you, it sounds like you are "driving a mains plug in reverse".

It should be easy for you to test your presumption about the inverters going dead; if true that removes some forms of risk. Maybe unplug the inverter from the mains and lick the inverter's output during the day [No, for other readers benefit, please don't do that!]

If not, why would an electrician look anywhere other than the fusebox to isolate the mains? Remember, you've had a heart attack or been knocked down by the Clapham omnibus.

A grid tie inverter is tied to the grid so that it can track it's voltage, no grid voltage  = no output as there is no line voltage to track, even your £50 crap from china does that as it's fundamental principle of operation of a grid tie inverter.

A good motto, which has literally saved my life on more than one occasion, is "Trust, but verify". One of those occasions was with a domestic electricity installation.

(The only other mottoes that are worth a damn are "Think" and "Be prepared".)

[Simon]

Of course.

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