Ground mount Solar PV

jaredGalen

Looking for opinions on placement of groundmounted 15 x 400w panels. Roof mounting is a no go.

Quote after grant is about 13k.

The purple line is south facing, but there is a good 80m run back to house and connections.

What should I consider with such a long run?

Should I consider altering the pure south aspect?

Bakka

https://www.boards.ie/discussion/2058255298/ground-mount-solar-pv

I have a ground mount 9.1kwh ---- 20 Ja solar 455 system . I went with an orentation of 150 degree angle. 90 is due East. 180 due South. So 150 is more South than East. I didn't go totally 180 South as there is large trees which would have blocked generation in a low lying winter sun. I also prefered the physical look of a more straighter line even though it is ever so slightly angled, it looks straight. You also seen to have trees/bushes etc directly due South. Are they tall, will they cause shade etc? If they do that will affect output from your panels. I would probably move the purple line to the blue line and have it at the same angle as the purple if it's possible.

jaredGalen

Thanks.

Those are 2 large trees that would need to go at the purple line.

Would need to go also for blue line placement. Have another to the west that would possibly block winter time sun of both.

The long cable run and associated losses makes the optimal placement a topic of concern, and what trees to knock. 🤦🏻‍♂️

slave1

If you are spending this effort and outlay then consider tiltable mount setup to allow you max high summer and low winter generation, most fixed tilts will be 45degrees but it's 60degrees for June and 14degrees for January to gain optimal generation

Citizen Six

https://www.boards.ie/discussion/comment/119363240#Comment_119363240

Can you just adjust position rather than cut down two trees? Seems to defeat the purpose of renewable energy if you cut down trees for it.

Punchin A Keyboard

I would be more thinking of a east west split either side of the hedge at the end of the blue line as a good option

DC999

1 - split: Yeah, E/W split would give a good spread over the day. Not sure if those are your sheds and have any machinery / farming stuff in them that would be used during the day. Not suggesting you're a farmer just because it's not a city housing estate :) But same principle for using power in morning and evening for anything. Doesn't need to be E/W split. Could be S and W if don't need much power in morning. Or E and S if don't need power in evening...

2 - losses based on distance: In terms of the cable length, measure the route yourself (for distance) and ask installer to confirm the gauge of wire needed so the losses are kept to a minimum balancing with the cost of the cable. f cable is too small it builds up heat meaning it's losing energy so it's wasted. And I'm assuming it can also do bad things to kit connected to it if undersized.

Bear in mind you may well want to add solar capacity in time so best to leave spare in the cable as a lot of work to bury a cable 80m and cost. You can 'over panel' to get more than a 6kwp system. Without that capacity you'd need to run another cable.

The Will Prose website https://diysolarforum.com/ has stuff on how to see the % of losses across cable runs based on distance (there's a formula once you know the distance and either amps or voltage - can't recall which). If it was me I'd double that against what the installer was telling was the right cable thickness - it's your system losing efficiency forever so worth seeing are they 'cutting a corner'. @irishchris has a ground mount afaik and did a write up somewhere on this forum about it. I've a roof mounted so only spewing out what I've read about ground mounts.

3 - roof mounting is a no go you said:

Mind me asking why that is? Asking in case it's an option once you get the ground mount costs to compare. Ground mount will likely cost a lot more unless you can DIY a lot for the trench, cable run, frame build... Or have someone giving you a decent rate for that. Even price of metal or heavy duty timber for the frame will cost a whack. Looks like there is a lot of rook space but hard to tell what's the house, garage. Is shed to right yours and is that a circular roof....

bullit_dodger

I'd also be curious on #3 above from DC999. If you have a roof that you can mount onto, this is invariably the best solution.

As an alternative to #2 above, you could go with 2 or even 4 panel micro-inverters down at the ground mount. That way you would only have to run a long AC cable rather than DC cable. AC is less prone to losses over distance than DC and you can do the power transfer with a smaller (i.e. cheaper) cable.

saccaromyces

Hi all, Had guys out to fit panels, they said it would be a waste to put on roof because of shadows and having to split them, and the west side would give very little in winter.

They sugested a ground mount and couldn,t understand when I got survey this wasn,t suggested. I went back to co, who where not very happy with me changing now. now there quoting 21k before grant for, 18x 400wp panels

Ground mount system, sofar 6kw inverter, 2x 2.4kwh batteries. Seems expensive, help

poker--addict

shop around, you will get idea of reasonable prices and advice.

irishchris

https://www.boards.ie/discussion/comment/119515547#Comment_119515547

Absolutely shocking quote. Don't accept that and shop around. A lot of companies don't like the time labor and involved in ground mounted systems and can save yourself a lot if not going self install offer that you agree to do a lot of the digging trenching work to them and they will lower the quote often substantially.