Solar for Beginners [ask your questions here]

graememk

https://www.boards.ie/discussion/comment/121305076#Comment_121305076

Buy once, cry once.

But the kicker is how do you know how good the " expensive" one is!

ColemanY2K

i've got my shopping list together for the ground mount install. assume the panels and inverter are in position (which they will be next week), i just need to buy the rest of the kit.

i'd appreciate it if ye can review this and advise if i'm missing anything before i order and get the electrician around to install:

2 packs x SWA MC4 Connector Pair (pk20)

1 x Projoy 32A 4Pole AC Isolator

1 x IMO 32A DC Isolator 4-pole 2-string

1 x ThinkWe 4 Pole (2-string) Fire Safety Switch (I'm a little uncomfortable not putting in a fireman switch)

1 x Eastron SDM120A Single Phase Energy Meter

1 x Set of SEAI compliant PV warning labels

1 x 35m PV Cable (Red)

1 x 35m PV Cable (Black)

The inverter is in the garage, will the sparky need to put in a second consumer unit besides the one that is already in the utility?

10-10-20

https://www.boards.ie/discussion/comment/121310698#Comment_121310698

MC4 Crimps and is the cable sized correctly for the load and voltage-drop?

Isn't the fireman switch duplicated by the 4-pole isolator though?

And the Eastron SDM120A is AC powered, how are you putting it onto this DC load?

ColemanY2K

https://www.boards.ie/discussion/comment/121310884#Comment_121310884

1. yup have the crimps and checked the cable size is fine. the run is much less than 35m.....just allowed myself plenty of extra.
2. possibly, but i'm going off the shopping list from midsummer. would appreciate clarification on this as the fireman switches are expensive.
3. it won't be on the DC load.

AmpMan

If you are not getting the grant you don't need the fireman switch.

and also if you do get the fireman switch you'll need 4 more pairs of MC4s

ColemanY2K

https://www.boards.ie/discussion/comment/121311008#Comment_121311008

no grant, this is a new build. the fireman switch does sound a little OTT when a DC isolator is present in the same space.

ColemanY2K

order placed 😁

fafy

A question on exporting.

When you export to the grid, is this AC, or is it DC. I assume its AC, but just wanted to be sure.

Also,

if you were able to generate say 8kw, this is limited to 5 kw being exported, and for some of the balance, you could charge your PV battery ? What happens any DC excess left ?

unkel

https://www.boards.ie/discussion/comment/121316046#Comment_121316046

1. Your panels produce DC. Your inverter "inverts" DC to AC which goes to the grid
2. No. You are only allowed to install a 5.5kW inverter max (unless you apply for a bigger system) and it can do 5.5kW max in total. So if your solar panels are producing the equivalent of 8kW then 2.5kW is lost (or technically speaking it is never produced) as your inverter simply can't do anything with it

fafy

https://www.boards.ie/discussion/comment/121317371#Comment_121317371

Thanks for explaining,

i was under the understanding that if you were producing 8 kw dc, and you have an 8kw invertor, then 2.5 kw of that produced DC ,could be used to charge the PV battery as it accepts dc, leaving 5.5kw available to invert to AC, and export, is that incorrect ?

bullit_dodger

https://www.boards.ie/discussion/comment/121317570#Comment_121317570

Yes.....and no. :-) It's not a straight answer.

There are brands of inverters out there (Huawei I think is one of them) which can do what you say, that being if your producing say 8kw from the panels, that it will give charge the battery first, lets say that's 3Kw and then export the remainder (5Kw) out to the grid. But the majority of inverters usually are limited to dealing with that 5Kw or 5.5Kw in total.

My own Givenergy one is rated to 5.5Kw, but yet I've seen it spike and handle 6.2-6.3kw for a few minutes. The battery taking 2.5Kw and then it exporting 3.8Kw to the Grid. It then does settle down though to a max of 5.5Kw inverted after awhile... so it can't sustain that.

To be fair, it's great an all if your inverter can deal with it, but for the vast majority of the time (vast majority), your inverter won't be at full capacity. For 99% of people - I wouldn't worry too much about it.

graememk

https://www.boards.ie/discussion/comment/121317371#Comment_121317371

Extension of point 2.

The max power that can leave the inverter is 25amps, (actually works out at 5.75kw, but no inverter is that size)

There is some inverters, I know solis, hawuaei can do this, and others can fill in for other inverters.

If an array is oversized people have seen more than the output of the inverter being produced

Eg 7kw being generated, 5 going to batteries and 2 being exported.

fafy

Thanks to both, for the guidance !

n21roadie

Can I ask if SAJ H1-6K-S2 is a good and reliable Inverter or is there a better one ?

ColemanY2K

I have a 5kW Solis Hybrid inverter. It's maxed out with the panels I've got hooked up to it. However I have 310m2 of roof space facing almost perfectly due east and west, no shading whatsoever.

My question is how can I add a second inverter without breaking the ESBN 25amp rule i.e. is it possible to have the power generated by this potentially huge bank of panels directed solely to the house and batteries? It seems I have this wonderful opportunity to generate oodles of power over and above the existing 7.8kWp array in the garden.

The local substations (which one is mine I'm unsure of) have plenty of capacity.

The photo was taken this morning and got me thinking.....

NC7 would be a last resort. I'd rather spend that 1k on something else than take a gamble.

graememk

https://www.boards.ie/discussion/comment/121326907#Comment_121326907

One way of doing it is get a big battery.

Keep all the new solar on the DC side of the battery, Charge the battery directly using charge controllers [ie off grid garage style]

your grid tied system hasn't changed. [although i would look into changing the inverter to maybe a sunsynk 5.5 that can do 120 amps from the battery. (in the summer you might as well export it so the batteries are empty for the next day)]

Jonathan

https://www.boards.ie/discussion/comment/121326907#Comment_121326907

Talk to @TerraSolis. He has had success with NC7.

There is lad on the FB group who has gone all out and created a completely three phase islanded Victron system off a single phase grid connection. I think he's a Victron installer though.

The other option is to connect the panels directly to DC loads (DC immersion, DC air conditioning units etc), but there is only so much generation that they can soak up.

ColemanY2K

Thanks folks. Lots to ponder.

Gusser09

Hi All,

I know this has been asked before but here goes. We have 4 sides on our house. East West North and South. Our East / West Roof is small enough and I think we'll be lucky to get 4 panels in on each due to roof design. Same goes for our directly south Facing roof. It is approx 4 Meters x 2 Meters. However the North facing roof is long and could fit a few panels on it too. Is it worth getting them given the cost is relatively low? See pic attached taken in May. It gets really good sunlight during the summer months for about 3 hours. What do you think?

West facing roof below. East facing is identical.

North facing gable

orangerhyme

The limit on domestic rooftop solar has been removed.

The limit on free standing ground solar for private houses is 25 Sq metres.

Does anyone know if you can get both or is it either or?

Also the planning permission exemption for farms is 75sq meters.

Do you have to be literally a farmer or if you've a big field next to your house can you call it a farm?

AmpMan

Anyone running 2 inverters?

I'd like to compliment my 6kw E/W non hybrid inverter with a small hybrid inverter (2.5kw ) on my south facing garage.

Question is , will the hybrid inverter only charge the battery with its own array or will it use the excess from the other array ?

I would be getting a decent size battery.15kwh

I know putting a hybrid with battery on the larger array is the obvious answer.

jasgrif11

I have 4 :)

I have 2 grid-tied Sofar inverters, 1 x Solis Hybrid Inverter (but it's set up as grid-tied) and 1 X Sofar Hybrid. The Sofar Hybrid takes excess from others and charges my 40kWh battery

kave2

Hi folks, I'm posting this here as this might be completely wrong. Still learning.

Am I correct saying 10 x 410W panels would generate around 3700kwh annually, south facing roof in Galway?

Tried using https://re.jrc.ec.europa.eu/pvg_tools/en/ but not sure if I have done it correctly. It is showing me 3720 annual generation.

How much would Eddi use to heat hot water cylinder annually? Is there any way to calculate?

Our el. usage for last 12 months was 2200kwh, we are using gas to heat hot water atm (gas usage would go down a bit too). That would leave us with 1500kwh to heat water and rest back to grid.

I'm trying to calculate ROI. Thanks a lot.

Liam2021

Hi all

Looking for recommendations for a good company in the meath area to install panels.

10-10-20

https://www.boards.ie/discussion/comment/121336077#Comment_121336077

Correct for a fully South orientated system and a loss of 14% (roof mounted and slope 35).

The rest of the question sounds like a task for Gary's utility!

https://garydoessolar.com/utilities/dailymodellingutility/

Hope it helps!

Gusser09

https://www.boards.ie/discussion/comment/121331185#Comment_121331185

Thanks for all of the help here folks. Great thread.

TaurenDruid

Is it normal for companies to just... ignore... what you've actually asked for?

Context: Went to Ideal Homes, decided on maxing what we can do panel-wise after talking to people at several stands. First company came out, quoted for exactly what we wanted. They reckon they can give us 12 or 13 panels on front and back of a SE/NW house, appropriate inverter, hot water diverter, and 10kWh battery.

Second company, Bórd Gáis (well, a company working for them) came out this week. I unfortunately wasn't there, had to be in the office, but their quote arrived in. Quoted for 5x panels only ("You don't want to put panels on the NW-facing roof, it won't get enough sun" - it gets direct sun in summer from around 2-ish until sunset!); a 3kWh inverter, no battery, and no hot water diverter ("One of those will short out your immersion because if it's not full sunlight it'll be going on and off every few minutes.")

Like - what they've said is all pretty much bollocks, right, and the contractor is only looking to do their standard fit-out? There was also "Book now and we can fit you in before Xmas, Feb-March is peak busy time for us and prices will be going up!" talk from the guy, apparently.

idc

https://www.boards.ie/discussion/comment/121344144#Comment_121344144

I'd say avoid companies tied to suppliers, they probably have a simple playbook, fit small amount of panels, enough to a difference but not enough to mean you won't still need to pay the supplier for electricity. And they won't even consider stuff like North facing. In total I think I had 6 companies visit and a 7th refused to visit if wife not at sales pitch!! Of those most won't even consider my SW single storey extension as neighbours roof shades it at times. But the company I did pick listened to me and were happy i was aware of the shading issues and still went ahead with the full install. If I'd got with someone else I'd only got 2.4kWp (whereas i got 4.6 instead with two roofes and have since added more on a shed!)

As for the hot diverter they havn't a clue -- its not a on/off based on surplus. If you have 1kW surplus the diverter uses 1kW. If you 2 surplus the diverter send 2kW to diverter up to what the max your immersion uses.

Liam2021

Looking for some advise on the day night Meter and pv system. Getting a system installed in January and currently have a day night meter. What type of meter do I need to be able to export surplus power back to grid? Also can I use a smart day night meter if there is such a thing?

ratracer

Following on from the question above……are all the new smart meters that have been installed by ESB Networks day/night meters, or is there a different type?