Solar for Beginners [ask your questions here]

unkel

https://www.boards.ie/discussion/comment/120366805#Comment_120366805

I've heard of deemed rent, but I am pretty certain that Ireland doesn't tax based on deemed rent. Can't see how deemed rent is relevant here anyway. Nobody is saying they are not getting paid for their export. Deemed or otherwise 😂

con747

https://www.boards.ie/discussion/comment/120366916#Comment_120366916

Kind of nearly irrelevant now we know each person on the electricity bill gets a €200 exemption so put a few names on it and you would need to be exporting massive amounts to be caught for any tax. I know not everyone can do that but a lot of us can.

ColemanY2K

Have seen over on the quote thread talk about getting the nc6 in before the new rules come in in May. The nc6 asks for the mprn number. My issue is we're a few weeks away from first fix on our gaf. At what point will esbn advise the mprn number? Please don't tell me it's not until the meter is installed. I've googled but can't find the answer.

jkforde

I'd ring ESBN, the one time I did I was very pleasantly surprised by the helpfulness and friendliness of the support agent

gg3390

Hello,

Spent most of yesterday evening reading through this thread, and learned (or at least read) a lot about solar PV. I have some questions, if anybody has time to comment. I'll state at the outset I've no experience or knowledge with solar PV, but I do understand electronics and electrics pretty well.

I've been thinking about going down the DIY route, and installing my own panels. As I said I understand the electrical side pretty well, plus neighbour is a registered electrician and would be able to connect and sign off on any install from that perspective. I think the questions I have might be better suited to this thread, rather than the DIY thread, and hopefully I'm correct here - if not please let me know.

1. I understand that from May, ESB are changing the rules regarding grid-connect PV, and it would be better if I had submitted an NC6 form before this deadline so as to be able to install a 6kw inverter, as opposed to a 5.5kw. If I'm considering a DIY route, and am thinking of buying the equipment piecemeal, is it possible to now complete an NC6 form, without having the equipment bought or to hand? I was considering purchasing a Solis 6kw hybrid inverter, as I might have access to UPS battery banks down the line (unsure if these would be suitable for this or not, but at least with the hybrid inverter I'd have the option to add batteries in any case, be they ups types or not). Regardless, it would be the summer before I could consider buying and installing the equipment in any case.
2. I'm thinking of erecting the panels on a south-facing (approx 35degree) single storey garage, that is behind and to the north of my house. The early morning sun would not be as good as I would hope as there is a lrge hedge and a neighbours garage on the opposite side of my garage, but once the sun rises somewhat, should have a decent footprint on this roof. One concern I have here is the potential wind loading on the roof. It's a single storey garage, and the rafters are not of the dwellinghouse size, but perfectly adequate for the garage roof, which is slated (man-made slates). Roof is easily accessible though. Assuming a roofer (the installation of the panel runner I'd not be comfortable with) installs the runner, is there any potential for roof uplift due to wind, and/or additional structural loading due to the panels? I understand panels could be 20kg or more each, and I'd be thinking of installing 12 of them - 6 on each string of the inverter. I also note the requirement to keep panels in 500mm from edge so as to minimise any potential loads due to wind changes close to the edge of the roof.
3. There is a sub-consumer unit located in this garage, fed from the main MCU in the house via 4core armoured 10sq cable. Ther eis no easy route back to the house to install a separate AC cable from the interter to the house MCU. After discussing with the electrician, he sees no reason why the AC output of the inverter cannot be fed from the garage consumer unit, as he believes the cable already there is perfectly adequate for the potential amperage generated. Would this be an unusual case, or is it an accepted workaround to installing a new cable. All other services, such as CAT6 ethernet and wifi are already available in the garage, so from a monitoring perspective, I'd have no issue.
4. A lot of threads here have mentioned Solis inverters, and these seem to be popular, but what is less clear is what actual solar panel to use. I take it getting the max possible wattage output might be the way to go - ie 350-400w panels, monocrystalline, bearing in mind the open-circuit limits of the inverter and no. of panels installed, plus, what I understand to be the accepted over-subscription of panels (circa 8kwp for a 6kw inverter). Have I understood this correctly?
5. Assuming my thoughts are correct, are there any brand or model of panel I should look for, or indeed any specific types to avoid?

I apologise if any of these questions are silly, or make no sense, and I welcome any thoughts. Thanks for the most helpful, if not daunting, information already presented here on the topic.

Kind regards

con747

https://www.boards.ie/discussion/comment/120375724#Comment_120375724

Some here submitted the NC6 months in advance but it seems there have been some changes in relation to that so you need to find out what has changed. As far as panels go as some here say the best panel is the cheapest panel but just make sure they are Tier 1 panels. The higher wattage usually means the panels are bigger so not always the best way to go depending on how many you can fit.

As far as the 10sq cable goes I think it is sufficient but others here will know for sure. The inverters do handle more than they are rated for but again that is a question for someone else to guide you on.

slave1

10sq is more than enough unless it is an outrageous long cable run

gg3390

https://www.boards.ie/discussion/comment/120376572#Comment_120376572

Thanks for your input - appreciate the time. I'll await any further comments.

gg3390

https://www.boards.ie/discussion/comment/120377348#Comment_120377348

max 10m, so should be good to feed inverter AC output to the house via the garage sub-MCU so. Thank you for taking the time to reply.

gg3390

https://www.boards.ie/discussion/comment/120375724#Comment_120375724

As an addendum to the multitude of previous questions, specifically against the q on the NC6 form, if I were to set the inverter to never export, and only match house load, do I still need to submit an NC6 to ESBN?

I fear this board will be getting loads of questions from me - I apologise in advance.

olympicweights

I'm thinking of adding some more panels to my existing setup - so I have a few questions for those in the know to see if it is doable.

I currently have 12x395 Jinko panels south facing (52 degree roof) and 8x395 Jinko panels east facing (45 degree roof) for a total of 7.9kWp on a Solis 6kW inverter.

Now that west is starting to kick in I am wondering if I should add some panels to a 5 degree west facing roof on a pergola I built last summer. It has a corrugated iron roof and access is easy.

Theoretically I could add maybe 6 panels connected up with the east string (8 panels). That would be 14 panels in total (open circuit voltage of panels is 36.9, so 36.9*14=516.6V so <600V). Both wouldn't get solar at the same time so the total should never get near the maximum for the inverter, but given the 5 degree pitch the roof should benefit from the south as well as west.

So the first question is optimisers, given the east-west split are optimisers required on all east and west panels for them to perform correctly? The west roof isn't shaded but when the sun comes around towards west the east will start to shade. Fitting optimisers to the new panels isn't a problem but adding them to the east panels might be as I hope to do as much as possible myself and an extra €400 on optimisers isn't ideal coupled with them being another part to fail in the future.

If I can overcome the optimiser scenario is there a particular way that these extra panels need to be connected to the east panels? I presume I need a shut off switch close to the new panels (this could go under pergola roof) and then feed in the cables to the inverter location. Can these cables then be connected in to the inverter with the east cables?

Maybe different connectors will be required at the inverter etc but for now I just want to explore the viability of adding more panels and if that is possible I can delve into the other details then.

Thanks for reading.

bullit_dodger

If you have different orientations of panels on a string, you'll need optimizers on all the panels on that string. That's a pretty low Voc on those panels. Most of them are in the 40's. Meaning that it's rare that you can safely get more than 12 panels on a string. 13 is usually the exception. The fact that you can get 14 is super rare. Have a look though at the current limits, you will be pushing your inverter pretty hard. You might be limited there on the current side.

I'm not a huge fan of optimizers if I'm honest, but this one keeps coming up. Optimizers are less likely to fail than your string inverter. They operate at 40v as it's on the panel level, as opposed to 400-500v on the string inverter. Most of then are guaranteed for 25 years while string inverters are usually guaranteed for 10 years or so.....and they fail "passively", as in if they do fail, they fail as if they weren't in the system.

That said, I'd have a look at micro-inverters. Would seem that you might be pushing the boundaries of your old installation hard. Micro-inverters could enable you to add as many as you like. You got a battery in your existing installation?

Aside: Not sure you have gone through your first summer yet, but you will (unless you are doing HEAVY use) probably have WAY more power than you need in summer months with your existing 8kwp

olympicweights

Didn't expect a reply that quick, thanks! Yes only new to solar but it gets addictive 😁

I've a 5kW purdrive battery and a 50kW EV to soak up a decent amount. FIT will hopefully add up over summer months and will be adding wife's name to the electricity bill.

I'll check out the current limits on the inverter. The installers did mention 12 panels max on the south facing string so maybe current related more than voltage.

With an east west split I presume it would be highly unlikely for all panels to be maxed out so possibly safer in that case as often east/west is oversized?

bullit_dodger

I'm East/West myself, and while generally that's true about they wouldn't be maxed out at the same time.....in the summer months (May-June-July) the sun is over head at 70 deg from the horizon and beating down pretty straight on both the east west panels at noon. That's the case that you'd have to worry about. The middle of Feb, Oct or Dec not so much as the sun is lower - but give it another few weeks and mid April you'll be clipping that inverter for sure :-)

I'd say you could be looking at 50-60Kwhr/day on sunny days from May-July with your existing setup.

olympicweights

I think I might be better off leaving it as is then. On my best day last week (30kWp) the inverter was under pressure for a good chunk of the day, I can only imagine if I was lucky enough to get 50+.

No point in replacing the inverter prematurely for marginal gains either side of peak summer months.

Thanks again for the advice ☀️

unkel

https://www.boards.ie/discussion/comment/120406725#Comment_120406725

Inverters are well up for that task, they also usually come with a very long warranty. Wouldn't let that put you off. But in your case I would also go with a separate inverter (or micro inverters) for your extra panels, simply because it's cheaper and less hassle (than to add 14 optimizers)

bullit_dodger

https://www.boards.ie/discussion/comment/120406725#Comment_120406725

Ohh you -will- get 50kWh/day for sure with that setup! Not everyday mind you, but come mid-april onwards you'll be in the 40's regularly enough. That's the problem with solar, it's feast/famine in summer/winter because we're so far north. I've friends living in South Africa and while they have less panels they get a much more stable production through the year as they are 35 deg south, the sun is much more overhead for the majority of the year

olympicweights

https://www.boards.ie/discussion/comment/120406811#Comment_120406811

I will probably hold off for now and see what the summer brings.

However, if I added another inverter and ran the extra panels to it how does this tie in with the existing system. I presume excess cant go to the battery as the inverter won't be hybrid? Can Eddi and Zappi connect to this? Apologies if there are basic questions but still very new to this!

unkel

You only need one hybrid, as the new micro inverters will just contribute to your house's net "export" that the hybrid will see. For the same reason eddi and zappi will work perfectly fine. You can use a myenergi CT clamp on the new inverter so it gets reported into your app

simpsimp

I understand that from May, ESB are changing the rules regarding grid-connect PV, and it would be better if I had submitted an NC6 form before this deadline so as to be able to install a 6kw inverter, as opposed to a 5.5kw.

I can't seem to find a reference for this, but would be interested to hear more..?

con747

https://www.boards.ie/discussion/comment/120407500#Comment_120407500

A thread here https://www.boards.ie/discussion/2058288583/esbn-new-regulations-on-nc6-form-on-6kw-25amp-inverters-may-31-2023#latest

Jonathan

https://www.boards.ie/discussion/comment/120407500#Comment_120407500

See here;

https://www.esbnetworks.ie/new-connections/generator-connections-group/micro-generators-

alfa_aficionado

Looking for some advice from the Solar experts on here...

Our electricity consumption is ~50units ea day, probably split almost evenly (50:50) between day and night units.

I have been playing around with PGIS; in order to try and maximise generation from the panels it would be best to have them on 3 separate roofs - I can only fit a maximum of 6 panels on the south-facing roof & so was looking to try and get panels that are as powerful as possible, e.g. Jinko Tiger Neo N-type 60HL4-(V) rated at 470WP.

To avoid mismatches I would probably get all the same panels but what options are there for connecting 3 strings to an inverter? I was thinking of trying to install 6 south-facing panels, 6 west-facing panels and 12 east-facing panels (according to PGIS, at my location east-facing panels are slightly more productive over the entire 12 month period)

I would get a hybrid inverter but might hold off on battery storage initially - there are 2 EVs so fortunately I can drive one whilst the other is charging.

Is it easy to add a DIY battery afterwards? Is there anything I have to ensure the installer does so that I can add a battery later (apart from making sure a hybrid inverter is fitted)?

Anything I've forgotten??

Thanks in advance

slave1

The option of more than two strings into an inverter is cost prohibitive.

Battery down the line should be straightforward once you have a hybrid inverter but you are paying a lot more for the hybrid inverter so be careful on the financial viability of choosing a battery with both FIT and two EVs available

The number of panels will be determined by your choice of inverter so you need to make sure your inverter can take X number of panels. You are likely looking at a 5.5kW max inverter now esbnetworks have cracked down on 6kW inverters (separate thread on this)

unkel

Some inverters have dual inputs per MPPT and can handle double the current. Like the Sunsynk 8.8kW. You could then have the 12 E on MPPT1 and the 6 W and 6 S on the dual input on MPPT2

slave1

...but NC7 required.......

Mr Q

A non hybrid inverter like a SMA Sunny Boy has 4 pairs of inputs for strings. This could also work for the three orientations mentioned above.

There are probably other brands offering similar that would be also under the NC6 application limit.

Then add a Sofar or similar later when adding a battery.

ELM327

https://www.boards.ie/discussion/comment/120415411#Comment_120415411

Interestingly as export limiters are allowed for NC7 but not NC6, there is nowhere to apply for a greater than 6kW inverter (soon to be 5kW) where you keep your existing MEC of 6kW or 5kW.

EG if you add a second non hybrid inverter and limit both it and your main inverter to 2.5kW each, this will not be covered under nc7 (have to be above 6kW MEC to apply) and would not appear to be covered under NC6 as limiters are not recognised.

Of course, there are other less blatant ways around this and doing the work yourself and monitoring export and setting up so you cannot exceed MEC. This is what most of us on here are doing and I suspect its the path Ill go down. I've been back and forth with an irish provider of solar carports and will be adding another 7kWp in all likelihood to a solis string inverter I bought from Unkel! I had other plans for it initially but I think it makes sense to use for the carport.

bullit_dodger

https://www.boards.ie/discussion/comment/120413820#Comment_120413820

So with three roofs, you are unusual - but a good few people have dealt with this. Typically the "easiest" way is to get a 2x string inverter and put optimizers on the panels on your south (6) and west (6) facing roofs. Then the 12 east facing panels would go in on the other string (without optimizers). The use of optimizers is debatable. Some people couldn't be bothered, fearing that if one fails they'll have to go up onto the roof to replace it. There's some merit to that, but I think the failure rates are so low that it's like 1/100 (or there abouts) with 12 optimizers that you'll get a failure in 10 years. Those odds are fine in my book.

Going the 3 or 4 input string inverters would be the ideal solution as unkel mentions above, but those puppies are hard to get and (probably) beyond what a supplier will install for you, even if you supply the kit.

I'm also a big battery proponent, but with 2x EV's I'd be slow in your case. Your EV's will be able to soak up a lot of excess, assuming that one is present in the driveway when the sun is shining of course. Another option is to simply get a "normal" (non-hybrid) inverter and get down the road a ME3000.

If money was less than an issue though, with your consumption. Go big. 10Kwh battery along with 8-9Kwp in panel, hybrid inverter.

Aside: 50-50 split on consumption with day/night? You not charge the EV's at night?

SteelyDanJalapeno

Sorry it's probably been asked a dozen times, but can I diy a battery with a Huawei hybrid inverter?

micks_address

https://www.boards.ie/discussion/comment/120417419#Comment_120417419

Don't think so... Others will confirm

alfa_aficionado

https://www.boards.ie/discussion/comment/120415813#Comment_120415813

Yeah we do but have a heat pump as well; I could definitely improve it towards 60:40 in favour of the night rate but then everything will change once solar goes in!

If I can get the Jinko Tiger Neo N-type 60HL4-(V) rated at 470WP ea, panels then the total array size should be around 11.2Kwp; do any hybrid inverters (apart from the Huawei) allow both charging of battery and full AC power output at the same time? (I believe the Huawei allows 5Kw for both of these concurrently)

unkel

@alfa_aficionado - be careful with the high wattage panels. They are a con. In the way that they are not producing materially more electricity per sq meter of panel, the panels themselves are simply bigger. So fewer of them will fit on your roof. So take proper measurements of your roof and of how many panels of a certain make / model would fit, before you buy anything...

alfa_aficionado

Thanks @unkel - I did double check the dimensions because as you rightly point out a lot of the higher power panels are much larger. It's hard to find any definite source where these can be compared directly. I did look to see whether I could fit more of a smaller panel onto the roof but this isn't possible as I don't have enough space to fit 2 rows.

bullit_dodger

unkel's 100% spot on there. If it was made in the last 1-2 years, virtually all the panels are with 1% efficiency of each other. E.g

Longi 410w panels = 1722 x 1134 x 30mm = 1.95m^2. So watts per sq mq = 410w/1.95 = 210.25 watts/m^2

Longi 450 panels = 2094 x 1038 x 35mm = 2.17m^2. So watts per sq mq = 450w/2.17 = 207.37 watts/m^2

The initial thinking is that the 450w would be better, but as you can see above it only produces more because it's a bigger panel. In terms of actual efficiency the 410w panel is actually more efficient, although it should be noted that 3-4watts difference in a sq meter is nothing.

Ultimately, it depends on the size of your roof and how many of each you can fit. You might be able to fit more of the smaller panels giving you a higher overall output, or it may work out that the larger ones maximises your available space.

Sizes of a fair few panels can be gotten at midsummer e.g. Longi 450w Silver Framed Split Cell Mono (White Backsheet) (midsummer.ie)

alfa_aficionado

Another question on inverters again; what are my options given the proposed solar array size is 11.2Kwp? I think export limit can be set to max 6Kw in most inverters but what happens to the other 5.2Kw? (I realise that for most of the year, generation will be far below this but I would hope that during the summer there would be reasonably regular peak generation exceeding 6Kw) I presume the excess generation above 6Kw is "lost" with a standard 6Kw inverter?

I think the Sofar HYD 6000-EP has a max PV input power of 9Kwp, alongside a max grid output of 6Kw (3000...6000-EP – SOFAR (sofarsolar.eu)) so this sounds like it might be a good choice but presumably quite a bit more expensive than standard 6Kw inverters? I also cannot see anything online that

How would multiple inverters work?

Are there any alternatives to the Sofar ME3000SP that allow for a higher rate of battery charging?

I'm probably not going to install batteries immediately given that i can store energy in the EVs themselves but is it still better to try and get the installer to fit a hybrid inverter now rather than changing a standard inverter out later?

Mr Q

https://www.boards.ie/discussion/comment/120418017#Comment_120418017

What roof height/space do you have to work with for the install. Could you get two rows landscape instead of one row portrait?

If you can only get one row landscape what maximum height could the panels be?

ELM327

https://www.boards.ie/discussion/comment/120418126#Comment_120418126

My 6kW inverter can generate up to 8kW I've seen so far from my 8.2kWp array. I think 11kWp would be pushing it a bit on a normal 6kW inverter. If it were me I'd break that into 3 strings, and put the last 3-4kWp on a separate string inverter. Put your main inverter as a hybrid inverter, even if not getting batteries now, because 11kwp is a fk ton of electricity and you'll want to store that somewhere.

To answer your "lost" question, yes, if the inverter cannot handle any more you get clipping. This is the tradeoff of oversizing an inverter array, you are limited by the inverter in peak time but get higher generation most of the time

micks_address

https://www.boards.ie/discussion/comment/120418473#Comment_120418473

yeah its an interesting balancing act. During the winter i see max 2.5/3 kwh generation for december/jan.. but last week i was over 5 for periods of the day.. ive a 7kwp array split over 2 aspects/strings - south east/north west.. 4kwp/3kwp - my inverter is 5kw

Mr Q

I will be adding an additional 7.9kW over 3 directions later this year. All on one 3.6kW SMA inverter which is listed on the datasheet as max PV of 5.5kW.

SMA have a design tool and this will work fine according to it. But there are lots of variables between different panels, inverters, panel orientation etc.

I think 11kW of panels on a 6kW inverter would be possible.

alfa_aficionado

https://www.boards.ie/discussion/comment/120418365#Comment_120418365

Switching to landscape doesn't really get me any more panels - the roof has a depth of <2.5m

bullit_dodger

Most panels are 1.1m x 1.8x (approx). so if your roof has 2.5m you should be able to get 2x rows of landscape in there.

unkel

What @bullit_dodger said. In fact a standard size PV panel is just 165*99cm. All the bigger wattage ones we have seen in the last few years are massive cons. Be very aware, buy what fits while making sure your € per wattage is kept to a minimum.

alfa_aficionado

I thought there had to be a minimum gap of 50cm between the edge of the panel and the edge of the roof in all directions, meaning that the area of the roof that can be used is technically 1.5m? Maybe the installers don't really care but could it be an issue for the grant?

If that was the case then I could possibly get 2 rows in landscape.

bullit_dodger

https://www.boards.ie/discussion/comment/120426014#Comment_120426014

Apologises. I didn't know you were going for the grant, I thought this was a self-build and missed that in the thread. I think it's 30cm to the apex of the roof, but yeah, 50cm to the sides. Might be close to get 2x landscape in, but I think you could do it. Might have to go with smaller panels. I went for these guys myself for 2x panels I put on the shed.

Q Cells G9 350w Black Gappless mono module (midsummer.ie)

1.67m x 1.03m

Redlim

https://www.boards.ie/discussion/comment/120426014#Comment_120426014

From section 4.3.3 of the SEAI code of practice for installers it says you can go up to 200mm from the top of the ridge. Or is that referring to just the fixings perhaps?? My installer called SEAI before doing my install to check as we were a bit tight for space also and they gave the all clear for 200mm. But maybe there was a bit of confusion over what was being asked!

"The PV modules must not overhang the edge of the roof at any point, must not extend within 500mm of the roof edge/perimeter, and must not be fixed at the ridge cap/tile (which in many cases may be cemented in place) or within 200mm of the top of the ridge."

SPV-Code-of-Practice.pdf

bullit_dodger

No I think you are right Redlim. I thought it was 30cm, but I was working off memory. In that case you should be good alfa.

redmagic68

Has anyone considered or installed a Wi-Fi controlled fuse spur to control the immersion heater for hot water rather than an eddi?

I have a hp but don’t have the ability to control it remotely to activate it to heat the water when I’m away from home when we have excess solar. When we have to replace it down the road I’ll try find one that I can integrate with the solar or that allows Wi-Fi control but not until the current unit fails

I’m considering getting it to send the excess to the hot water tank manually, I did something similar with small oil rads controlled by Tapo plugs last few months and it worked really well, but don’t have need for space heating currently.

we have CEG so no benefit to feeding all the excess into the grid.

just wondering where others are on it?

bullit_dodger

I guess the biggest hurdle redmagic with that is getting a Wifi controlled relay which can take 16A - but yeah in theory it should be doable. It'd be an all or nothing though, an EDDI will detect (say) you have 400w excess going to the grid and then pump that into the element. You'd probably have to wait until you had say 2Kw being exported and then flick the switch. Should be automatable though easy enough assuming you have access to the Inverter telemetry letting you know what you are exporting at a specific time. Or a shelly etc.

graememk

https://www.boards.ie/discussion/comment/120428277#Comment_120428277

Search for water heater wifi switch, there's a few on Amazon that handle 20 amps.