Solar for Beginners [ask your questions here]

Calahonda52 · 15-03-2026 06:09PM

https://www.boards.ie/discussion/comment/124306180#Comment_124306180

Thanks, would something like this work back at the CU with all relevant sockets on that circuit: router/ wood burning stove

2 pole A- B switch

https://www.amazon.ie/Generator-Changeover-Switch-Reliable-Switching/dp/B0DDPJY81C/ref=asc_df_B0DDPJY81C?mcid=ce3d7dbb660b3964ad7a0aebe9cfcc37&tag=ieshopgode-21&linkCode=df0&hvadid=743936243910&hvpos=&hvnetw=g&hvrand=336572770445577940&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9040155&hvtargid=pla-2612654255032&psc=1&language=en_IE&gad_source=1

DayInTheBog · 15-03-2026 09:18PM

https://www.boards.ie/discussion/comment/124304520#Comment_124304520

Did you get anywhere with this ?

phunkadelic · 18-03-2026 02:51PM

Hi lads, I looked at solar a few years ago but my electricity usage was not high enough to bother with it. The house is 1900s victorian, with gas fired central heating. So heat pump is not an option.

What about getting a few electric heaters? Could that make sense for the extra electricity generated by the solar panels? I know electricity heating is the most expensive but, if I am generating it with solar, is it viable?

loyatemu · 18-03-2026 03:04PM

https://www.boards.ie/discussion/comment/124321713#Comment_124321713

are you planning to heat the house mainly in the summer? There's not much solar in the winter when you generally need most heating.

you'll get money from selling solar back to the grid, which can be used to offset your heating costs, but you'd still be better off sticking with gas which is much cheaper than electric heaters.

MacDanger · 18-03-2026 03:13PM

https://www.boards.ie/discussion/comment/124321713#Comment_124321713

Not really worth using elec heaters - at the times when you're generating solar, you probably won't need them and vice-versa.

If your elec usage is still very low, there may not be much point in getting solar at this stage IMO (the rate at which you sell back to the grid is pretty decent currently but who knows where that will go) - depends on what your annual elec bills come to?

HardcoR · 19-03-2026 08:41PM

https://www.boards.ie/discussion/comment/124315490#Comment_124315490

Not really, waiting for one place to respond but so far, no luck :/

lintdrummer · 19-03-2026 10:15PM

Any opinions on North facing panels? No issues with shading on the roof. I have an awkward shape roof. I can get 11x 460W Jinko panels on the south facing rear roof. Quote with 5KW Growatt hybrid inverter and 2x Growatt 5kw batteries is coming in at €8450 after grant. Adding 11x North facing panels and 11x optimisers comes to €11450 after grant. Putting the numbers into https://pvwatts.nlr.gov/pvwatts.php tells me to expect additional 2531kwh output from the north facing panels on top of 4191kwh from the south facing panels. Seems like it might be worth it and pay for itself within 5 years. I've read that north facing panels can be useful on duller days when the light reflecting off cloud hits them.

graememk · 19-03-2026 10:36PM

https://www.boards.ie/discussion/comment/124325626#Comment_124325626

Why the optimisers?

The EU one is more accurate for here

https://re.jrc.ec.europa.eu/pvg_tools/en/#PVP

But your estimate wouldn't be a mile away.

On the dull days they will perform just as well as the south

lintdrummer · 20-03-2026 12:10AM

https://www.boards.ie/discussion/comment/124325686#Comment_124325686

Thanks for that link. Broadly similar results, slightly better in fact.

I think the idea is that it would be one chain so the optimisers would be necessary to prevent the North facing panels from dragging down the output of the South facing ones on the brighter days. Open to correction though, I'm near clueless on this stuff.

graememk · 20-03-2026 08:58AM

https://www.boards.ie/discussion/comment/124325907#Comment_124325907

They would be on separate strings, no need for optimisers. Work independently from each other.

lintdrummer · 20-03-2026 10:31AM

https://www.boards.ie/discussion/comment/124326154#Comment_124326154

I'll have to query that so, thanks.

deezell · 20-03-2026 10:38AM

https://www.boards.ie/discussion/comment/124326343#Comment_124326343

Optimisers are only effective if there is a risk of strong shade on any string panel which will choke the productive panels, the Optimiser bypasses it. North face panels tend to have ambient light most of the day, with a small window of dawn and dusk direct sunlight in high summer, so very little shadow on a north facing surface.

10-10-20 · 20-03-2026 10:51AM

Going on from this discussion…

https://www.boards.ie/discussion/2058435974/200-oversizing

…you could argue that a N facing string would be less susceptible to max Voc jumps in cold and partial cloudy weather, so the string could be maxed almost right up to the inverter's MPPT voltage.

lintdrummer · 20-03-2026 12:12PM

https://www.boards.ie/discussion/comment/124326363#Comment_124326363

Reply from the rep says that the optimisers are necessary due to potential shading from chimneys on either side of the house.

unkel · 20-03-2026 11:32PM

https://www.boards.ie/discussion/comment/124326388#Comment_124326388

That's actually a good point that I don't think I have seen mentioned before. A N facing string would never even see its rated VoC, never mind going over it on a cold sunny day

10-10-20 · 21-03-2026 07:58AM

https://www.boards.ie/discussion/comment/124328616#Comment_124328616

Ah yeah, thats why they pay me the big bucks on here, for those fleeting moments of clarity...

...oh no, wait a moment

unkel · 21-03-2026 11:49AM

https://www.boards.ie/discussion/comment/124329007#Comment_124329007

You should become a moderator here on boards.ie. €45k per year and unlimited coke & hookers. Did that for almost 20 years. What a life.

witnessmenow · 21-03-2026 10:22PM

After doing some research on optimisers, and after watching a few videos on them I'm a bit less convinced on their usefulness than I was before.

The main benefit you see listed is about shading, so that a panel in shade doesn't drag down all other panels on the string, but apparently this only applies for partial shading of the cells (like a tree branch).

As I understand it, If it's something larger, like a chimney, and it's shading a full cell, all modern panels handle this through its bypass diode and you'll see no difference with or without optimisers. In either case, that portion of panel will be bypassed and the rest of the panels will operate as normal. Is this correct?

I'm a bit unsure what to do about them, we will have one string that will be made up of an upper SW roof and a lower SW roof that would be in shade from the house during the early morning, but I don't believe would be impacted by any other shading for the majority of the day. And if my understanding is right, optimisers wouldn't really be any advantage in this use case.

I'm not too worried about the cost of the optimisers, but adding a potential source of failure (do they have the same warranties as the panels? I assume not) and a 1-2% energy cost to run them if they have limited benefit doesn't seem like a good choice.

We may choose to put more panels on that string on a NW roof, which would be a good use case for optimisers if I understand correctly, but it probably only makes sense to do that if all the SW panels had optimisers anyways.

Anyone have any thoughts on this?

unkel · 21-03-2026 11:12PM

https://www.boards.ie/discussion/comment/124331028#Comment_124331028

Thankfully you did your research properly and you have come 100% to the right conclusion that you shouldn't add them. A SW string early in the morning doesn't produce much anyway

Optimizers and micro inverters on your roof should be avoided at all costs, unless you really have no other option. It is a last resort.

graememk · 21-03-2026 11:44PM

https://www.boards.ie/discussion/comment/124331028#Comment_124331028

That is my understanding too. Hard shadows will make the panel use it's bypass diodes, rendering the optimiser useless anyway.

And if on multiple aspects all panels will need optimisers

lintdrummer · 21-03-2026 11:59PM

Speaking of optimisers, I've had another quote today that avoids using optimisers on the North facing section altogether because the panels and the inverter offered have some in built optimisation. Thoughts on this quote?

22x 465w Aiko Solar panels monocrystalline = 10,2kwp system
1x Hypontec 5kw hybrid inverter with wifi dongle

3x Dyness 5.1kwh batteries

All other required materials including AC isolator, DC isolator, Fireman's switch, check meter etc.

Price after grant: €10200

deezell · 22-03-2026 12:10AM

https://www.boards.ie/discussion/comment/124331218#Comment_124331218

Agree with the above. Optimisers are a bit like those eddy immersion switches. Large extra cost for nominal benefit, Though theres trivial cost in labour to fit optiimisers as they're just fixed to and input from the panel DC, and output to the panels place in the series string, you'll find a big markup for each on your quote. Perhaps the installer is resistant to excluding them because it's such easy money.

Also, you only need them on panels with a big shading issue, panels with an all day view of the sun don't need them.

witnessmenow · 22-03-2026 07:18AM

https://www.boards.ie/discussion/comment/124331149#Comment_124331149

Potentially not early enough as I've already booked an installer! He doesn't seem to charge much for optimizer so I can't imagine its a big money maker or anything, I'll talk to him next week. The €50 or whatever they cost isnt really what concerns me, but in 10 years will I need to be paying someone to swap them out, that bothers me!

This is our roof, the back of the house is the SE and then we'd be using the house SW and the Garage SW. I'm not sure when this picture is taken, but judging by the shadow of the chimney its still relatively early and the lower roof is already clear. I'll keep an eye on it the next couple of days and to see if that roof is impacted by any other shading (Dusk it would be, but I can't imagine panels are up to much at that time)

In the mantra of getting as much panels as possible I'm also considering the NW roof, but that would require optimisers.
At current export rates each panel on the NW roof are worth €42-45 a year. I would have been blissfully ignorant about optimisers if I wasn't considering this roof.

tom1ie · 22-03-2026 10:44AM

Hi all, I’ve a couple of questions you might be able to help out on.
1) I have a dormer on the south facing side of my roof, can panels be fitted to dormer roofs but set at an optimal angle?
2) Can the panels be fitted to the walls of the dormer?
3) if shadows are cast by the dormer into the panels do I need optimizers?
4) the back of the roof is north facing and as I understand it, the north facing panels will generate approx 50% of what the south facing panels will- am I correct in thinking the north facing panels need to be on a separate input into the inverter (a second string) to avoid the north facing panels limiting the south facing panels?
5) I want to reduce my gas bill as much as possible, which I use to heat my water currently (power showers in house, we are not fans of electric showers!). In this case would an eddi divert or make sense to heat the water via the immersion.
6) If I was setup on the pin energy traffic, how many KWH can I export at the 25c per KWH rate at a 12 KVA connection? (I presume I’m 12KVA anyway?).
I ask this as I’m thinking that’s how I know what size battery’s I need to max out the benefit I could get from filling the batteries at the cheap rate and then exporting when the grid needs it most and pays the most- 25c per KWH I thin is it?

Thanks for any help!

HardcoR · 24-03-2026 09:59AM

https://www.boards.ie/discussion/comment/124325394#Comment_124325394

No luck, another installer not interested in this project.

josip · 24-03-2026 10:29AM

https://www.boards.ie/discussion/comment/124331708#Comment_124331708

Hi Tom, I see you've not gotten any replies from the more knowledgeable Boardsies, so given it's been 2 days I'll try my 2c. Fastest way to get the right answer on the internet is to post the wrong answer :)

Not sure what you mean by setting at an optimal angle. Most panels are mounted flat against the roof and there is scope for a few degrees of tilt for some of the mounts. But there's not much difference over the year between 30 & 50 degrees. You can set different angles here and see what works best.

https://re.jrc.ec.europa.eu/pvg_tools/en/#PVP

Bear in mind that if your system is over-dimensioned and your output will get clipped on good summer days, then the optimum angle for your panels might be one that maximises winter output.

2. Here is the SEAI Code of practice for installers which says wall mounted are allowed.

https://www.seai.ie/sites/default/files/publications/SPV-Code-of-Practice.pdf

and this technical bulletin helps to see where panels are allowed

https://share.google/45DsPy48MK0F8BZou

3. My understanding is that if it's a strong shadow by a solid object like a wall or chimney, you will need optimisers. Soft shadows by tree branches and you might be ok with the likes of Aiko Neostar.

4. Yes, North panels will need to be on a separate string. The more aspects you have on your install, the more MPPTs you will need on your hybrid inverter model.

5. Most people say that Eddis are not worth and a recent poll on the Irish Solar Facebook page confirmed that from owners. Immersion timers at off peal are preferred.

6. Many/most inverters limit to 5kW for NC6 so your maximum theoretical is 96kWh per day. The most I've seen on here from NC6 Boardsies is around 50kWh I think. Unkel might be exporting on some days for 21 out of 24 hours using his battery but not sure.

Now, let's see which of the above are correct :)

10-10-20 · 24-03-2026 11:26AM

https://www.boards.ie/discussion/comment/124331708#Comment_124331708

1) I have a dormer on the south facing side of my roof, can panels be fitted to dormer roofs but set at an optimal angle?

Not really as but they would be highly exposed AND you risk puncturing what is already a tricky roof to get water-tight.
2) Can the panels be fitted to the walls of the dormer?

Yes, you can fit panels to any suitable vertical surface.
3) if shadows are cast by the dormer into the panels do I need optimizers?

Now you're getting into the world of voodoo. That's a hybrid solar setup and there isn't an easy way to emulate what would happen if you had three aspects on one MPPT input. It may all work well with optimisers on all panels, or maybe you'll find that they aren't needed (due to the bypass diode above).
4) the back of the roof is north facing and as I understand it, the north facing panels will generate approx 50% of what the south facing panels will- am I correct in thinking the north facing panels need to be on a separate input into the inverter (a second string) to avoid the north facing panels limiting the south facing panels?

Correct. Typically two MPPT inputs for two strings.
5) I want to reduce my gas bill as much as possible, which I use to heat my water currently (power showers in house, we are not fans of electric showers!). In this case would an eddi divert or make sense to heat the water via the immersion.

Have a look back at some of the discussions around Eddi vs gas on here; the Eddi doesn't beat gas at heating water considering the cost of the unit and good solar FiT. If the FiT lowers, or the gas price falls (ha!), then the value proposition for Eddi lowers. But if gas rises… well you know.
6) If I was setup on the pin energy traffic, how many KWH can I export at the 25c per KWH rate at a 12 KVA connection? (I presume I’m 12KVA anyway?).

The easiest way to calculate that is by adding up the sum of the inverter export powers (which is limited by the Microgeneration scheme (see the NC6/NC7)). A 5kW inverter will be able to export 5kWh in one hour.

Hope it helps.

Dogsdodogsstuff · 25-03-2026 03:25PM

Have a crowd knocking around estate called energy centre from Duleek:

I’ve been considering panels but apathy and sort of half interest has me doing nothing.

From what I can see they do hard sell )so expect that). I imagine the fees quoted are at least slightly higher then if you pay up front (even though they say no interest).

Questions I was gonna ask :

- what happens to Unused electricity (do we get some credit from Esb for example , if we don’t have battery)

option to pay up front rather then weekly
How long to get installed (presumably they get the grant do could sit on it for ages?)
how much electricity should this generate and savings (although this could be sales pie in sky response)
what panels and investor installing (chatGBT suggested)
warranty
can we do 10-12 panels

Has anybody got any tips or advise and has anybody experience with this crowd ? From what I’ve seen hard sell but generally product good (if not over priced).

Bass Reeves · 25-03-2026 04:07PM

https://www.boards.ie/discussion/comment/124339906#Comment_124339906

I presume that the price quoted is for the 6 panel system nearly 7k for it ny the time the 5 years are up. No wooder they have no interest in payment up front they have the grant as well

deezell · 25-03-2026 04:17PM

5 years is 261 weeks is €6916.50 for the 8 panel, plus they get grant of €1675. Total of €8591, or roughly €1000 per panel installed. Ouchydoodles.

Solar for Beginners [ask your questions here]

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