Solar for Beginners [ask your questions here]

cgcsb

I've got 6 500w panels so theoretical 3kW capacity facing south west and yesterday without a cloud in the sky the peak output was 2kW. Currently not a cloud in the sky and output is currently 1.3kW. Perhaps the max capacity is based on the max possible at the equator??

magicbastarder

cheers - i did see when we just had eight panels at one point - the west facing aspect - we were getting 3.5kW which was spot on the theoretical max, so thought the theoretical max was possible.

the west facing aspect only has one panel optimised (just in case of shading from a chimney) but i guess the east+south aspects will be held back if one aspect is not chugging at full steam.

i was also just reading that the inverter can easily reach 75C, hotter than i would have guessed.

bullit_dodger

Your output depends on a lot of factors. Not just how much clouds are presents (albeit that's generally the big one).

The orientation of the panels and the slope also plays a factor. For example if your panels face south west, then they will only be doing their daily max in the afternoon around 3-4pm. If you are looking at the morning time they're sort of facing away from where the sun is and they won't be at their max

All that said though, it's actually temperature which plays the main part in output. Solar panels counterintuatively, don't like to be hot. They produce more when it's cold/cooler. So if it's broken clouds and the sun comes out from behind a cloud where the panels haven't been warmed, you will produce more than if the sun is beating down constantly warming a panel. Take the comparison of yesterday verses a day last week for me. Yesterday (in red) was pretty cloudless in Dublin.

You can see the "spikes" when the sun comes out from behind the clouds on the panels (which are cooler) in Blue and you can see it producing substantially more.

Busman Paddy Lasty

https://www.boards.ie/discussion/comment/123623762#Comment_123623762

Better than the equator. Perfect lab conditions at 20°C.

I've a 3kW system as well but I sort of consider it a 2.5kW system as its split some south and some west. In theory I should never make 3kW

noeldon

inverters ???

is it true that 5kw is the max allowed in Ireland? that said i did read earlier in this thread that some actually go to 5.xx but not quite 6.

then if you have a 9kw for example potential system and are getting close to that on a good day, does that mean everything after 5 is lost? Unless you add a battery?

Or are there inverters out there that can microgen the 5kw and use other capacity for self use / battery? if so, what inverters ??

conf101

Posted this elsewhere but this is probably the more appropriate thread so I'll move to here:

Had a survey today with a solar panel installer who essentially advised against a battery. They have an offer at the moment that includes a free 5Kw battery with 12 or more panels (which I'll be getting). He said there's definitely no need for any more battery space and if it wasn't free with the panels, he'd be advising me against getting a battery at all.

For context, my annual usage is approx. 3,500 Kw per year and I'm looking at getting 13 panels, so ~5.7kw system.

His advice is contrary to everything else I've read or been told. Does he have a point?

magicbastarder

we talked to one or two suppliers who suggested the same. it's one of those 'how long is a piece of string' questions.

let's say you generate 10 units a day, and you also use 10 units a day (which is your usage). at one extreme, with a battery, you might (in theory) not import or export electricity in that day - when you do consume electricity, it comes from the battery, and the solar tops that up; the battery buffers the generation for you.

but at the other end, depending on your usage patterns, without a battery, you could end up importing 10kWh and exporting 10kWh (you could be using power primarily at night, say).

so the theoretical difference between not having a battery and a battery, could be a) you don't pay anything for the 10 units of electricity you use, or b) you pay the difference between what you pay for importing ten units, and exporting 10 units.

if your price plan was (say - making the maths easy) 19c to export, and 29c to import, the price difference between those two extremes would be €1 per day. or, in maybe 5 or 6 years, the battery would pay for itself (based on what we paid for a 5kWh battery)

but also, without the battery, you wouldn't be able to do what some people do, and during the lean winter months, charge it in the wee small hours for 7c or 8c per unit; the rationale is that a kWh you've paid 8c per unit for is cheaper than forgoing getting the 19c for exporting that during the day, or possibly paying 29c to import it if you drain the battery (probably more to import if you're on an ultra cheap night plan).

conf101

Good summary, thanks. I can see the logic for either really

banie01

Folks, I know that many tend to avoid self-install for very valid reasons.
Particularly getting hold of a sparks and NC6 signoff.
But?
Lets assume that I have a relative who is RECI registered, competent and returning to Ireland soon.
Is there any means of a buyer picking up a kit like the Midlands Batteries kit ex VAT?

https://midlandbatteries.com/products/18-x-jinko-440w-solar-panels-5kw-hybrid-inverter-10-24kwh-battery-bank

Is there any similarly specced deals available for better value?I don't want to source via China if I can but local and still gain the VAT benefit.
My ideal setup is an 18 panel system with 10kw of batteries at €5k would leave me happy to even forgo the SEAI grant tbh.

graememk

No way around the VAT, as the exception is under supply and fit, and the 2/3 rule applies (the materials can't cost more than 2/3 of the total bill)

Unless your reci is VAT registered and they buy the stuff and install it.

antodeco

I want to move to energia night rate to get the 2am - 6am time slot.

What is the charging rate of a 10kw Dyness Power box Pro battery? (Including draw)?

I will be setting up the inverter and battery in my garage where there is also a dryer and a washing machine. I want to be able to run both during the EV window as well as charge the battery. Any issues with that?

magicbastarder

https://www.boards.ie/discussion/comment/123639364#Comment_123639364

You have someone to do the roofing part too?

serox_21

I've done a DIY setup similar to what you describe above:

12 Trina pv panels

1 Deye hybrid inverter

- Mounting system

- electrical cables, fuses, AC, DC disconnect

16Kwh battery

All in 5970€.

I had to pay for mounting the panels on the roof 90€ a piece to a roofing company(this is included in above price).

100€ to an electrician for mounting RCBO in the fuse board and signing NC6(I sent it to ESB).

Except the panels on the roof I did all the work.

serox_21

@banie01 your kit doesn't include mounting system for the panels. Price will go over 5K. And there will be crimping tools and other small bits required on the install day.

My above price included everything, van to rent, M50, screws, postage etc, cables on the AC side, backup sockets.

geographica

anyone else have this with Bord Gais Energy whereby they are not carrying out step 2, even though they advertising it? The guy rang me after I entered all my details and told me they will only site visit after I commit 🤔.

also looks like they are subcontracting to a private firm and it’s not their own teams

magicbastarder

i was told it's OHK doing the work for one of the big firms - can't remember if that was BG or EI though.

nearly all the companies i approached wanted to do a site visit as part of the initial sales process.

noeldon

https://www.boards.ie/discussion/comment/123640275#Comment_123640275

it's Electric Ireland

banie01

https://www.boards.ie/discussion/comment/123639458#Comment_123639458

He isn't, unfortunately. He is moving home in August and will be working in industrial electrics but will be keeping up his RECI status for the foreseeable too.

1jcdub

I've a question for the solar tech experts.

We had a solar installation about 3 years ago. 15 panels and 2 x 5kw batteries along with a solis inverter. It been working well. Then this week there was a planned power outage that started at 10am, and it was not available until after 5pm that day. I was leaving and the power was off. So I went to the fuse board and selected the switch the was installed for switching power between Mains, Off and batteries. And I switched this from mains to batteries as we have electric gates and I wanted to power them up so they could be left open through the day. I opened the gates and checked the battery percentage, it was at 96%. Then I selected the switch back to Mains and the power went off again. I wanted to keep the batteries power for the late afternoon. Then at 3pm I returned home and selected the switch from Mains to Batteries and nothing happened. No power at all. Nothing had tripped on the board. At 5PM the mains power came back on and everything was working again. I checked the battery level and it was 96%. So they hadn't been discharged to the grid.

So my question. Why was I able to use the batteries when switched over within a few minutes that morning. But that afternoon I had no power from the batteries when I selected the switch to batteries? But they still almost full…

Thanks

graememk

https://www.boards.ie/discussion/comment/123651724#Comment_123651724

Couple of things to check.

There could be a MCB tripped in the consumer unit beside the inverter on the output of the backup load.

Do you need to turn off the supply to the inverter when running on backup?

The startup load with everything off in a house can be too much for the solis. And the inverter errors out for a while.

Normally when we switched over to the solis backup, we turned all mcbs off and took everything back online slowly.

Maybe in the afternoon the fridge, freezer all tried to turn on at the same time. Sometimes you see a light flicker but at 3pm you wouldn't have any on!.

The MCB/rcbo to the inverter should be off if it stays on for a minute and shuts off again.