Next Storm

[Joeboy]

I've given this a LOT of thought over the last few weeks!

Here is my "plan" in the event of a multi-day outage:

• Disconnect house from grid via DNO's DP isolator.

• Switch off All breakers in CU.

• Go round the house unplugging/turning off anything non-essential.

• At Inverter move mains cable from "Grid" to "UPS".

• Turn on all breakers in CU except "Hob" and "Ovens".

In summer that'd be it. Job done. I'd have more power than I could use.

But... Since when did multi-day outages occur in summer?

So I'd have to purchase / hire a generator and run a cable from the generator to the "grid" connection of my inverter and set the charge-rate to something sensible. Obviously I'd have to take what I could get but something like this: https://www.machinemart.co.uk/p/clarke- ... generator/ should do the job. I imagine filling it up with fuel in the morning setting it running until the fuel ran out then lasting on batteries until the next day.

The critical parts are: not knowing how long the outage will last. If you know it's going to be 5-10 days, buying a genny is a no-brainer. But if the power is coming back on tomorrow it doesn't seem worth the hassle/money. I'm also not prepared to buy a genny "in case", because it'll probably never happen, so will have to move fast before generators are sold out everywhere.

Cracking post, anyone else have genset thoughts or plans? I like the simplicity of 'filling it up with fuel in the morning setting it running until the fuel ran out then lasting on batteries until the next day'.
This is another facet to the benefits of low consumption homes. we can run a long time on not much.

[Bugtownboy]

Joe, you just need a Stirling Engine generator to sit on top of the WB - you’d be sorted

[Marcus]

I find i'm ahead of the game on this one:- i last connected to the grid 6 weeks ago to weld the link box back together ( i can weld from the powerjack inverter, but on the highest setting the welder upsets the GTI's I use to backfeed power from the PV, so I tend to plug in to my 'Grid socket').

As this subject has come up I thought I might ask about a friends question:-
just yesterday he asked what i would recommend for him:- he had a fallen tree take out his supply on the Friday and it took WPD about 24hrs to restore his power - Saturday was quite sunny here. if very windy, and he was looking at his 2kw PV array in the sun and wishing he could access the power.

As he's on the high FIT and has another `15yrs I wouldn't want to interfere with that, but at the same time he doesn't want to spend money on an entire stand-alone system. I was wondering what folks on here do/ might do?

My best thought was one of those combi inverters (which i think folks have alluded to on here?) that can run without a battery, and fitting a 2nd d.c. isolator to the existing PV; in the event of an outage, isolate from the GTI, switch d.c. to the combi and run an extension out. But: he wants to run the borehole pump and I'm not sure what those inverters can actually do without a battery connected. Obviously a battery would make for a much better system, but if it's only for occasional use when the grid is down I can't see it is justified.

Could anyone recommend a brand/model for a combi inverter as a starting point - i can't remember where or what i was looking at before.

[nowty]

My SMA Sunny Island battery inverter is grid connected but has an automatic whole house back up function. If I lose the grid, the battery inverter first fully disconnects me from the grid with a 100A contactor. Then starts up in Off Grid mode within 2 or 3 seconds. And as I have a UPS for the internet and computer I don't even lose the internet connection.

The icing on the cake is that the SMA PV inverters still operate with the Sunny Island and throttle the power based on AC frequency shift.

When the grid comes back, the Sunny Island first resyncs with the grid frequency, then alters its output voltage to match the grid before reconnecting to the grid.

[Stinsy]

I find i'm ahead of the game on this one:- i last connected to the grid 6 weeks ago to weld the link box back together ( i can weld from the powerjack inverter, but on the highest setting the welder upsets the GTI's I use to backfeed power from the PV, so I tend to plug in to my 'Grid socket').

As this subject has come up I thought I might ask about a friends question:-
just yesterday he asked what i would recommend for him:- he had a fallen tree take out his supply on the Friday and it took WPD about 24hrs to restore his power - Saturday was quite sunny here. if very windy, and he was looking at his 2kw PV array in the sun and wishing he could access the power.

As he's on the high FIT and has another `15yrs I wouldn't want to interfere with that, but at the same time he doesn't want to spend money on an entire stand-alone system. I was wondering what folks on here do/ might do?

My best thought was one of those combi inverters (which i think folks have alluded to on here?) that can run without a battery, and fitting a 2nd d.c. isolator to the existing PV; in the event of an outage, isolate from the GTI, switch d.c. to the combi and run an extension out. But: he wants to run the borehole pump and I'm not sure what those inverters can actually do without a battery connected. Obviously a battery would make for a much better system, but if it's only for occasional use when the grid is down I can't see it is justified.

Could anyone recommend a brand/model for a combi inverter as a starting point - i can't remember where or what i was looking at before.

An AC-coupled battery system would be the obvious choice so as to not upset the FiT. This is particularly worthwhile if your friend is on “deemed export”. For backup in the event of an outage, the simple solution is to have a couple of sockets near the battery inverter that run off of the batteries/solar when the grid is down. The other solution is a “whole house changeover switch” but this is more complex/ expensive.

[Joeboy]

I find i'm ahead of the game on this one:- i last connected to the grid 6 weeks ago to weld the link box back together ( i can weld from the powerjack inverter, but on the highest setting the welder upsets the GTI's I use to backfeed power from the PV, so I tend to plug in to my 'Grid socket').

As this subject has come up I thought I might ask about a friends question:-
just yesterday he asked what i would recommend for him:- he had a fallen tree take out his supply on the Friday and it took WPD about 24hrs to restore his power - Saturday was quite sunny here. if very windy, and he was looking at his 2kw PV array in the sun and wishing he could access the power.

As he's on the high FIT and has another `15yrs I wouldn't want to interfere with that, but at the same time he doesn't want to spend money on an entire stand-alone system. I was wondering what folks on here do/ might do?

My best thought was one of those combi inverters (which i think folks have alluded to on here?) that can run without a battery, and fitting a 2nd d.c. isolator to the existing PV; in the event of an outage, isolate from the GTI, switch d.c. to the combi and run an extension out. But: he wants to run the borehole pump and I'm not sure what those inverters can actually do without a battery connected. Obviously a battery would make for a much better system, but if it's only for occasional use when the grid is down I can't see it is justified.

Could anyone recommend a brand/model for a combi inverter as a starting point - i can't remember where or what i was looking at before.

Marcus, can I ask which country you live in? Amazed and pleasantly surprised that you can be offgrid for 6 weeks at this time of year. Smashing!
I did see a 48vdc/240vac inverter today on amazon. It had the solar inputs on it. Just looked but its not showing up right now. Not sure if it would have worked without battery though.

[Joeboy]

This any use? I think he'd be needing some form of battery too but could be inexpensive way to go?
https://www.amazon.co.uk/LONGRING-Inver ... 139&sr=8-4

[Marcus]

Exotic west Wales - hence I've got hydro-electric - currently running ~330w as it's been a relatively dry autumn - I'm usually flat out at ~450w by now. I've actually gone 9 months without switching to the grid before now, but that's the record. I'm also used to adapting my use to available power - facilitated by the fact that i live alone so don't have to keep anyone else happy* .

I've been thinking some more and I suspect my friend will be best off with a portable genny TBH - even if we did get an inverter to work with his existing PV, it would only help if it happens to be sunny whilst the grid is down - not good odds in winter in these parts.


*except kizzy the cat of course - she needs to be kept warm and comfortable in all weather.

[Joeboy]

Ah tres exotic! SWMBO & I were on a Wales tour back in June this year. First time in Wales, absolutely loved it. Going back next year. Impressed at the hydro, nice. I often wonder if people can go biofuel & genny combo? I have run my mazda bongo on a 60/40 veg oil/diesel mix. Works well.

[Joeboy]

Found this video this morning on a quick search. Bigger brother of the unit i ordered. I kind of like the guys German/Australian style of presentation.