Solar panels at home, worth it?

DrPsychia

https://www.boards.ie/discussion/comment/122107402#Comment_122107402

Which brands offered here should one buy that provide good interoperability?

slave1

There's a dedicated forum and massive quote/advice thread here

https://www.boards.ie/discussion/2058329045/domestic-solar-pv-quotes-2024-no-pm-requests-see-mod-note-post-1

...Ghost...

https://www.boards.ie/discussion/comment/122111292#Comment_122111292

Maybe this thread should be moved to the renewable energies forum?

DaveyDave

Cheaper isn't false economy when you're using reputable, well known components. You can buy stuff that isn't Huawei and still have a quality product.

That's the sort of logic that the Activ8 customers have when they spent €2-3k more than everyone else who got a €5k setup...

ted1

Huwaei are so reputable their telecoms equipment are banned in many countries

sunneysun7

Thanks for the information.

RoyRitar

It’s been a while since your post, but I still wanted to say something.
Considering solar panels for your crib? I went for it myself, and it's been pretty rad.

Ev fan

Would totally agree with your thinking. My esb bill for the last 12 months net was less than eur 100 including fueling an EV. However it's not just about money it's also about doing your bit in increasing use of greener energies.

fafy

We got 18 panels installed in late January, and went operational February 1st, as of today, we generated 3,775 kWh, over 152 days until today, of that, 81 % was exported, or 3,049 kWH, i got my latest bill today, and am €344 in credit after current bill, with the 3 bills since install,(1st bill was partly pre solar install) totalling minus €177. Appreciate winter won’t be like this, but i’l have circa €700 in credit before October comes.

It is very clear now, i will generate in excess of what i normally consume annually, which is 6,250 kWh, we have one low mileage EV charging at home, no electric showers - the single biggest user of electricity, and a heat pump.

The grant also came through, we were inspected in early June, so that delayed it somewhat.

It of course depends on your consumption, and, how many panels you can fit, and individual setup. but repeating a few things, what many others have told me, all of which i have found to be very accurate:

1)max out your panels.

2) combine with a suitable tarriff, and max out low night rates.

3) Export everything, allthough realistically, that is only possible with a large battery.

4) Look carefully at the supplier export rates which varies significantly by up to 9 cent a unit, from the lowest (Yuno 16 cent) to the highest (Pinergy 25 cent), the export rates will drop overtime, but so will the unit consumption rates, look carefully as well, at the day and night rates. My day rates have fallen away to 15 %, that will be 0 % when battery goes in for the vast bulk of the year.

Currently on a day /night tarriff, but 15 kw battery is being activated hopefully next week, so will be moving to a smart tarriff, with 3 to 4 hours at a sub 8 cent night rate, to charge battery at night, and power the house fully from battery during the day, that will suffice for at least 9 months of the year, but won’t always be possible during cold snaps, as i have a heat pump.

djan

https://www.boards.ie/discussion/comment/122368603#Comment_122368603

Great and very detailed write up. Seems to have worked out well for ye. Would you by any chance have a rough number on ROI accounting for the electricity grants/credits?

fafy

https://www.boards.ie/discussion/comment/122368827#Comment_122368827

That is very much user circumstances specific, and depends on so many variables:

How many panels you can get fitted

Invertor capacity, and type

Equipment selected - panel & invertor quality, battery choice or no battery, hot water divertor, cabling involved.

What your annual usage is, and as important your specific split between night and day, and individual household requirements, eg EV, Heatpump y/n

Battery size match to ones needs

The most suitable tarriff and export rates applicable to your own individual setup.

There is also the € unquantifiable as many have already said, it is good to generate your own electricity.

I did my own details, and tweaked it for scenarios, and it came out around 7.5 years ROI. but it is an ever changing situation, with tarrifs slowly dropping. as will export rates, and waited for 4 months for the battery to drop, which it did by about 1k.

Theres a bit of “homework” involved in it

raspberrypi67

I'm wondering with typical setups of PV on the roof, how many Inverters are used ? Only one or is it better to have two for redundancy reasons in case one should fail? My second question is how is the wiring done in terms of reaching the fuse board which is in my Front room, used to be a garage but converted. My third question, I'm going to invest in a better 'solar cylinder' next year which will be Solar Ready, so to speak, before getting panels, how hot can the water actually get when power is diverted to heat it, generally…3 person house. Well, it is now!! Used to be 5.

DaveyDave

https://www.boards.ie/discussion/comment/122633974#Comment_122633974

The wiring really depends on your house and the company doing it. My fuse board is in the utility room in the middle of the house, which is apparently an annoyance for electricians, but the company I used took the time to lift our floored attic and run wires down the wall following the extractor fan in place.

I've seen some shoddy wiring run across people's kitchens with white plastic covers on the solar Facebook group, you can also have wiring run externally to a box next to the meter outside (i.e, run along the roof, tucked behind a rain water pipe) or have an external cable run down the house into the living room. There's a house near me that has rear South facing panels and a thick cable run over the roof, down the front of the house into the board beside the front door and it looks awful to be honest.

raspberrypi67

https://www.boards.ie/discussion/comment/122634196#Comment_122634196

I think i'd prefer it coming down off the roof and entering a wall instead of messing with the inside of the house tbh

zg3409

https://www.boards.ie/discussion/comment/122633974#Comment_122633974

Note you may not need a solar cylinder. Most systems use the ordinary old electric water heater (immersion), to heat the water. If you are getting paid more to export than night rate it makes financial sense to heat water on dumb timer say 4am-6am and export excess daytime. If you hear on a timer it will get as hot as normal. If you pay 500/600 euro for a solar diverter like eddi it can geat water only from sun, in summer it will reach max temperature by noon, but at September it may be boiling some days and cold other days. Better to just use a timer on low night rate. Ideally really big really insulated tank and have showers from hot tank rather than instant shower like Triton..

Alkers

https://www.boards.ie/discussion/comment/122638808#Comment_122638808

All depends on how they're heating water otherwise - normally gas or oil. They're the rates that need to be included in the comparison toa work out which isncheale

allycavs

Anyone who has solar panels for 10 years - are you still getting 400kwh per panel approx ?

If they produce less after 10 years then its really not worth it

graememk

https://www.boards.ie/discussion/comment/122814529#Comment_122814529

Panels 10yrs ago were a lot smaller and less efficient (about 200-250w) so you'll not get 400w,

Panels in 4 yrs here, and generating more or less the same. (Extremely hard to compare, as perfect days are few and far between)

allycavs

Hi @graememk when you say generating more or less the same what do you mean?

Ya given Irish weather id be interested to know over a year what kw your solar panels produced and how many panels have you

crisco10

https://www.boards.ie/discussion/comment/122819497#Comment_122819497

There’s a whole thread over here discussing production :

https://www.boards.ie/discussion/2058103000/daily-pv-production

graememk

https://www.boards.ie/discussion/comment/122819497#Comment_122819497

Every where is slightly different due to location, aspect and slope.

But as a really rough rule of thumb you multiply the kW of panels by 0.8 and you get your yearly kWh.

Or more accurately, use this, which is pretty good on average, some months you beat it, some months you don't, but on average it works out pretty accurately

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

pad406

https://www.boards.ie/discussion/comment/122819539#Comment_122819539

Yearly Mwh you meant?

graememk

https://www.boards.ie/discussion/comment/122820585#Comment_122820585

Ah yes. Should have said W of panels gets you kWh

...Ghost...

https://www.boards.ie/discussion/comment/122820585#Comment_122820585

MWh 😉

...Ghost...

https://www.boards.ie/discussion/comment/122952413#Comment_122952413

Solar & EV should be completely separate decisions, because in nearly all cases, solar doesn't compliment EV. The only exceptions are when there is no export payment for solar AND the EV is parked at home during the day to avail of the excess.

Otherwise it makes much more sense to export the excess solar and charge the EV on a cheap night rate tariff.

I agree though that Solar is a great idea if you can get it and not pay extortionate rates some of the installers are charging. I got some quotes that were nearly 3 times the price of what I paid for the the exact same equipment.

CivilEx

https://www.boards.ie/discussion/comment/122958224#Comment_122958224

I agree with you broadly on separating the decision between Solar and EV, but I've two colleagues at work in the last 12 months where their solar installation has resulted in building up a significant credit on their electricity account.

One then went and bought a hybrid and another is considering an EV as a way of lowering their motoring costs to "use up" their electricity credit….cart before the horse perhaps, but that's how some get to the EV decision point.

Ev fan

https://www.boards.ie/discussion/comment/122961409#Comment_122961409

Certainly intro of fit payment largely separates an EV ownership decision from running Solar panels. What I have found with solar credits is that they reduce significantly the larger bills which come during the winter. The other issue with having an EV is charging it at cheap night electric rates. This then makes you consider home batteries to stretch cheap electric rates to as much of the daý as possible to avoid expensive day rates.

...Ghost...

https://www.boards.ie/discussion/comment/122961409#Comment_122961409

Certainly nice to be in credit, or be paid out that credit.

I just wouldn't want people being drawn in to either technology with the wrong idea. It's a lovely thought to charge your EV from the sun, but realistically, it won't suit the majority of people doing it that way and it's also not as advantageous, as I am learning for myself.

I've been an EV driver for 8 years now. I learned very quickly that it made financial sense to switch my energy tariff to the night rate to charge the EV and to then move the washing machine and dish washer to start their cycle after midnight. 60% of my power was being consumed during the cheap night rate, so my bills actually reduced for a while until the hikes in recent times since the war in Ukraine.

So, with electricity bills of €800 per 2 months, I really needed to reduce this and got 5kwp of solar in April. Batteries made sense to me, because I wanted to store excess solar and when I knew I could charge batteries on the cheap rate from the grid, it was a game changer. I've invested around €10k up front for the solar, electric upgrades and 40kWh of DIY solar storage which has reduced my electricity bills by about 75%.

I would only export to the car if I had no batteries, or the export rate was less than the rate I get when charging the car. The grid wants us to use the power at night after all.

https://www.boards.ie/discussion/comment/122961529#Comment_122961529

As above

graememk

https://www.boards.ie/discussion/comment/122962113#Comment_122962113

Before FIT 400-500 ish kwh into the car from solar.. After.. 0. I dont think I plugged the car in at all to charge from solar this year at all

slave1

In 2023 I got 15k kms into the cars at home, this year barely anything as more financially efficient to export