My 16kWp Domestic System

unkel

No doubt you mentioned it before @mp3guy, but was your current kVA connection? And how much is it costing to upgrade?

Didn't know max export was 17kW on single phase NC7, I had it in my head is was only 11kW

mp3guy

Currently 12kVA according to the ESB, but my meter fuse is 80A and my MCB is 63A whatever that implies.

This is costing €4k, as part of a larger building project I'm undertaking at home. I'm rural, and the transformer is right on my doorstep, and I'm the only property on it.

graememk

https://www.boards.ie/discussion/comment/121264309#Comment_121264309

12kva has a consumer 63amp mcb and an 80 amp esbn fuse

mp3guy

https://www.boards.ie/discussion/comment/121264329#Comment_121264329

Cheers. Found it on page 4 here also now https://safeelectric.ie/contractors/wp-content/uploads/sites/2/2019/07/July-2019-Newsletter-Final.pdf

unkel

https://www.boards.ie/discussion/comment/121264309#Comment_121264309

You probably needed the upgraded tails as I presuming you're going all electric to future proof your home? €4k isn't the worst, you're effectively doubling the power. If you can go 29kVA single phase, it's hardly worthwile trying to go 3 phase. Although the idea of 22kW EV charging that you can easily and cheaply do on 3 phase is sweet 😁

What plans do you have for your electricity provider and do you mind sharing how big your battery is (or will be) and how powerful your battery inverter?

Jonathan

https://www.boards.ie/discussion/comment/121264467#Comment_121264467

Get a phase converter and you still can have 22kW charging 😉

mp3guy

Yeah, will be all electric in good time. 16kVA wasn't enough for what was required, 20kVA barely and if you're going for 20, which is already the "next grade up" above "enhanced" 16, might as well just get 29 while at it and max out single phase. Nearest three phase is a km or two away.

Not sure about provider, surprisingly I'll still be classed a "domestic" and not business so I can pretty much go with whoever, though I'll be restricted to a 24h meter for the short term. ESBN got on to me about replacing my day/night with a smart meter and when I told them I was going up to 29kVA they said smart meters of that capacity are due in 2024, we'll see about that.

My battery is still just 18.9kWh behind a 5kW inverter. I'll definitely consider going for that 13kW beast once things are approaching break even point.

unkel

24h meter is nasty just going into winter season with very little PV output even from a large setup, but I suppose you had that last year too. I suppose you do get deemed export though, which is good in winter, that eases the pain a little bit

Be careful about break even calculations though. Waiting for the current system to pay off before investing in bigger can be a false economy. With extremely generous FITs now standard, you will make a fortune if you can feed it all back into the grid. Once you get a smart meter, make sure to get as many people on the bill as possible, it's €400 per person per year income tax exempt

KCross

https://www.boards.ie/discussion/comment/121264329#Comment_121264329

It seems that is inconsistent. I’ve the enhanced 16kVA connection and I’ve an 80A fuse in the meter box.

I questioned ESB on it and they said that’s what’s required. 🤷‍♂️

To have the 100A fuse you need a different fuse holder as the fuse is a physically different size/shape. If the fuse holder has “60A/80A“ written on it then the max you can have is the 80A fuse.

unkel

https://www.boards.ie/discussion/comment/121265581#Comment_121265581

I just hope you didn't pay extra for a 16kVA connection over a 12kVA connection, because you got the latter 😂

graememk

https://www.boards.ie/discussion/comment/121265581#Comment_121265581

When I had mine upgraded, they didnt change the head but did say they put in a 100Amp fuse. But its the 60/80 head.

The MCB should trip before the fuse would blow anyway.

curioustony

I wonder if ESBN would do an NC7 without any works or upgrades purely to allow the user to have a larger inverter/storage with export limiting.

My thinking would be to have battery big enough to cover one to two days of winter HP with inverter that will comfortably cover domestic load.

Would also ease the time restrictions for EV charging during the good solar months.

Assumes a decent off peak (whatever the suppliers call it) rate.

The alternate is to have a second system that is effectively export isolated from the grid, that sounds more complex and inflexible than it should be. €1000 to ESBN for export limiting might well be worth it in this scenario. Thoughts?

KCross

https://www.boards.ie/discussion/comment/121265610#Comment_121265610

I regularly use 70-80A and no fuse blown yet in 10+ yrs so that would suggest I have what I asked for.

Even if there was a 100A fuse in the meter you wouldn’t be able to utilise it.

unkel

https://www.boards.ie/discussion/comment/121266510#Comment_121266510

I have the standard 12kVA connection, 63A fuse in the CU and 80A fuse in the ESB meter box. It lets me draw near 15kW constant (63A). Have seen it go over a bit for a few seconds, but not much. But I suspect that is the 63A grid limit that I have set in the Myenergi appliances, rather than the max my connection can actually do before the CU fuse blows 😁

Maybe I should set the Myenergi to 70A and see what happens 😀

Why are you saying you wouldn't be able to utilise 100A? I could easily utilise well over 100A. If my connection had it, I would use it.

KCross

https://www.boards.ie/discussion/comment/121266619#Comment_121266619

Why are you saying you wouldn't be able to utilise 100A? I could easily utilise well over 100A. If my connection had it, I would use it.

Your wiring and CU fuse would be 80A. You wouldn’t be able to go to 100A as your CU fuse would trip first.

unkel

Ah got you. I thought you meant that if you did have a proper 100A connection, you somehow wouldn't be able to use it.

jasgrif11

I was doing a little experiment overnight, charging my car and battery during a 4-hour window to see if the Energia Smart Drive plan would work for me before moving forward.

I noticed that I seem to max out at 12kW between battery charging, car charging, heat-pump and general house supply (which would be low between 2-4am). I'm 90% sure I have a 16 kVA supply (fuse in meter box says 60/80 Series 7).

The test result is that my car only added 20kWh instead of 28kWh (7kW X 4 hours). This is a result of my battery charging at 5kw and my heat pump at 4kw (it spikes every 30 mins during the night).

Before I go 100% confirming with the ESB on my supply, could it be that my Zappi thinks I have a 12kVA supply or is that not even a thing?

Ignore beyond 6am as I indeed did start the car charging again

graememk

https://www.boards.ie/discussion/comment/121326865#Comment_121326865

Your main fuse in your consumer unit needs to be an 80amp for a 16kva supply.

curioustony

On the energia plan, remember to check for fair use limits. It works well for me, no EV and I'm on the older version of that plan with 4 rates. The newer one has 2 I think so the jump if you exceed limits is penal, assuming it still has them

Jonathan

https://www.boards.ie/discussion/comment/121326938#Comment_121326938

The overage is no longer penal. Goes from 8.15c to 9.38c

jasgrif11

I’ll need to cut the power to check that fuse. Will do that this morning.

I’m aware of the 9.38c upper limit with Energia. I’ll definitely hit that within the two month billing cycle. I’m ok with that if it means I can keep my battery (40kWh) charged and both EVs topped up.

graememk

https://www.boards.ie/discussion/comment/121326938#Comment_121326938

On the EV plan it's 1000kwh per month, but the penalty isn't near as bad as the EV one, it's something like 8c to 10c

jasgrif11

I checked the consumer fuse and it is indeed 80A

Looking at the Zappi "Advanced" menu there is a sub-menu called "Supply Grid" with two options "Device" and "Network"

Under "Device" There is a "Max Grid Power" setting. It is currently OFF. Should I set this to 16kWh?

Under "Network" There is a "Grid Limit" setting/ It is currently listed at 50A, should this be changed?

ECO_Mental

https://www.boards.ie/discussion/comment/121327262#Comment_121327262

I have a 16kVA connection and my ESB fuse is 100Amp. The main consumer board trip/RCD is 83 Amps.

unkel

You need to set your grid limit to 80A on your zappi, @jasgrif11

80A fuse in consumer unit = 16kVA connection (max 18-19kW or so)

63A fuse in consuer unit = 12kVA connection (max 14-15kW or so)

jasgrif11

When I try change the Zappi Grid Limit from 50A to 80A it only allows me to go as high as 65A.

Has anyone seen this?

graememk

https://www.boards.ie/discussion/comment/121328098#Comment_121328098

Hard wired or harvi for the CT?

jasgrif11

Harvi.

Although I think I can route the CT directly into the Zappi. I think I remember seeing someone before (can't find it now) that hard-wired will allow up to 100A and a limit of 65A via Harvi.

Jonathan

https://www.boards.ie/discussion/comment/121328212#Comment_121328212

Correct.

Note: When using a harvi to measure the grid supply, the highest value you can set this to is 65 Amps. The maximum current limit when using a hardwired CT is 100A.

https://www.myenergi.com/wiki/zappi-v2/13650-2/

jasgrif11

I managed to route some CAT5 into the Zappi. I'm planning to use this to extend the CT. I noticed that the CT connection on the Zappi is a special connector. Does anyone know what this is called and what size I need to get?

(The connector is on the left)