Panel split advice

MarryLurphy

Hi,

Looking for some education before I start my solar journey.

Budget allows me to get up to 20 panels on a 6kw hybrid inverter (DIY battery to come later).

Roof wise I am not limited for space.

One thing I'm not sure about is should I do a 50/50 split or should I put more on the "bad" side for winter production.

Green is ESE & Blue is WNW. My heart says go 50/50 and add more on the blue array next year😎 .........

Thanks in advance.

Marry

bullit_dodger

Unless you can get it installed today, you won't be able to get a 6Kw inverter. Well technically 25A is the new limit if you want the exact limit, which at a nominal 230v would be 5.7Kw

Micro-Generators (esbnetworks.ie)

Generally you should maximise the south facing array as much as possible. There are a few folks on here who have north'ish facing panels and while they are ok and WILL generate, they are complete rubbish in winter and only "come alive" from March onwards to oct. IN these months though they do contribute a decent amount so are worthwhile in getting.

A lot of it is down to where and how you use your power. If you are primarily a heavy user in the morning, then I'd 80-20 the E/W roofs. If your later in the day I'd probably 60-40 it. I don't think there's a "wrong" answer, more around what's better for you. Usual constant advice is maximimise your panels as much as you can from the get go. With a 5.7Kw inverter, your probably looking at 8Kwp as a limit in panels, and I'd stretch yourself to get that from the getgo.

MarryLurphy

Thanks Bulletdoger .

some good info there. We would use more in the evenings.

That is also when our EV would be plugged in (zappi), I'll be getting an eddi too.

DC999

I’ve the same orientations you have. WNW goes to sleep from end Sept to mid March. Produces next to nothing as the sun won’t hit them. See have you a photo of the roof from times of the year to check when it’s in sun. So outside of those months, it will give evening sun.

Per panel (in the 10 months we’re live):

ESE panel (per panel) has created 200kWh

WNW panel (per panel) has created only 132kWh, or 35% less. Which means I made 35% less FIT from those or have a 35% longer payback. They are great for the 6 months they produce and give us evening output. I don’t regret having them, but they will produce less.

Solar won’t produce much at all after 8pm even on the longer days. And it’s waned output wise at that point. So you won’t be able to charge your car and run the house if you only get home at 7pm say. There just won’t be enough juice.

To show that, here’s my rockstar best-day-ever yesterday below. Nose dives from 8pm (4.9kWp system). And it’s on the wane from maybe 4pm (yours would be earlier as I’ve a very small South that extends our afternoon).

In the longer term, we’ll be on smart meters. So you get paid for export (called FIT). Meaning you get paid for what’s not used when you’re not home or using it. FIT is ~20c a kWh now but could drop to 0 or rise – energy market determines that.

And if you are getting a large DIY battery down the line, I’d suggest add more on E and that fills the battery while you’re at work. Then less on WNW (for the 6 months it produces). Then use the battery in the evening.

If FIT and a cheap night rate are close in price, you can charge the EV at night at no extra cost.

DC999

Do you have any South you can use? The south facing shed on top right yours? Could consider that too as WNW wont produce for 6 months. So could do large E and S (as much as roof takes).

Panels are about 1.2m wide and 1.7m high so measure the width of it and you’ll get a sense how many you could fit. Need some space around the edge for the SEAI grant, but you’ll get a rough sense. South will produce the most, so make more on FIT.

Single story will get more shading than 2 story roof (from trees, other houses). So you can check where the sun and shadows hit it. In winter the sun is lower in the sky so will pick up more shading possibly.

MarryLurphy

Yes the shed is mine.

Its a about 10m long. Shed is supplied with a 6sq cable but I've no easy route to get DC cables to the house.

Its SW facing .

10-10-20

https://www.boards.ie/discussion/comment/120661968#Comment_120661968

Yes, but appears to me to be compromised by the house's shadow. But you do have an ideal garden...