Solar for Dummies.

con747

https://www.boards.ie/discussion/comment/120439640#Comment_120439640

FIT is based on the size of the inverter not the install yeah?

shanec1928

With zero vat on the horizon, solar is back on the agenda, wanting to double-check my logic here.

South facing roof with space for approx 20 - 22 panels, work from home and ev at home most days. My thinking here is just to go for the 20 or 22 panels, the biggest inverter\ hybrid inverter and run with that and potentially get batteries down the road if needs be.

bullit_dodger

https://www.boards.ie/discussion/comment/120442370#Comment_120442370

Typically 12 panels is the max you can get on a string, so with 2x strings your normally looking at 24 panels max Kwp for a domestic installation. Considering your talking 20-22 panels, if you have the space, go for the full limit. (Check with installer as some panels have a higher voltage - but it's usually voltage limited, although not always)

Panels are about €200 each on the day of install, so not that much of an addon in costs if you have the space on your roof.

Manion

OK

March

• Exported 88.85kW 
• Generated 335.2 kW
• Consumption ratio is 74% 
• Existing Battery - 10kWh 
• Installation 8.2 KWp

I'm serious considering getting another 5 kWh battery to improve my consumption. Very unexpectedly I'm finding that basically from now I'm generating enough power on average to cover my weekly demand. I'm importing at night approximately 3-5kWh to top up the battery and run the house and this is less than what I'm currently exporting daily. The issue is that the battery is hitting 10% - 15% by mid night and I want the whole start of the day off the grid. Is it madness to be looking to add another 50% storage capacity. Price point is 2.6K supply and fit.

micks_address

https://www.boards.ie/discussion/comment/120442958#Comment_120442958

i added a battery on top of our 9.5 so that i have 13.6kw useable now.. probably more than i need but at least i know ill cover dark days in winter without any hassle for peak tarrif times.. in december i was getting to 7pm some evenings and empty.. admittedly that was after a sunday cooking etc so maths probably didn't stack up to get the second battery

bullit_dodger

https://www.boards.ie/discussion/comment/120442958#Comment_120442958

As many will know here, I'm a huge battery fan - even leaving the fiscal side alone.

In your case, I'd probably hold off though. You've not been through the good summer months yet. Once you have, you'll have a better appreciation for the north facing panels, what generation your getting when it comes on stream, etc. You'll find that from now until Sept your installation will generate more and more in the morning before you get up meaning that you will be able to start the day consuming from solar rather than the battery. Sun comes up at 4-5am in June!

It depends a little on what tariff your on (D/N with deemed export verses smart meter) but if you were on a smart meter there's even a scenario where it makes sense to charge your battery up completely from night rate (cheap at say @€0.08/kwhr), and then start dumping it to the grid at 9:05am (gets you FIT - @€0.20/kwh) Meaning with your 10Kwh battery you'd be "earning" €1/day roughly.

So I'd hold off for a bit and see what your consumption is like.

SteelyDanJalapeno

It may have been asked before, but I can't see it, for a ground mounted system, I'll have my inverter at the panels, so I'll be running AC to the house, about 40 metres.

Is there a specific ducting I need to use? I can I choose.

Thanks!

Manion

https://www.boards.ie/discussion/comment/120443008#Comment_120443008

At the moment I'm about to move onto Energia day night rate of 48c/23c which is more than double my current rate. I've managed to shift my grid consumption to 80% off peak. Every month is a learning exercise for sure and I'm constantly changing the inverter settings.

graememk

https://www.boards.ie/discussion/comment/120443545#Comment_120443545

How does the flogas d/n work out for you,

Higher FIT but higher standing charge

Manion

I've a standard digital meter, no smart meter. Not keen going down that road

slave1

https://www.boards.ie/discussion/comment/120442946#Comment_120442946

Careful on panels, I know we always say panels max but it's voltage max, most I could get with my install was 8 per string (because they are 455w panels no doubt). I choose 455w panels as this absolutely maximised the space I had on offer, sometimes you might get more combined wattage/space with higher number of smaller panels, depends...

graememk

https://www.boards.ie/discussion/comment/120443753#Comment_120443753

They have standard d/n plans, fit (and that includes deemed) is 24c

https://www.flogas.ie/residential/price-plans/fixed-rate-elec-1yr.html

Higher standing though with 39c/19c

JayBee66

I have often wondered (but have not had time to research) why we fill our PV batteries to 100% but are told not to charge an EV or mobile phone beyond 80%.

Are PV batteries set up to report 100% but there is still capacity in the battery so that we don't over charge or are we damaging our PV batteries?

I assume the BMS in a phone is a lot less sophisticated than the one in an EV but I would have thought that the BMS in EVs and PVs are pretty similar.

graememk

https://www.boards.ie/discussion/comment/120457084#Comment_120457084

It's mainly due to house batteries being lithium iron phosphate.

They don't get to a high voltage until 98/99% and quickly settle.

redmagic68

https://www.boards.ie/discussion/comment/120445512#Comment_120445512

I have a little spreadsheet that I enter the D/N rates, Ceg and standing charge on. It’s set up for 13MWH usage with 4MWH day and 9MWH night. We have 8.4kwp split east west and 9.6kwh battery.

Flogas is coming in cheapest by €200 at the monument but massively more than my current enervgia ev rates of 8.5c and 29.5c.

Makes for scary viewing for the winter ahead but drops the ROI on the solar system which is a positive.

The more the rates rise and the gap widens between day and night rates the more increased storage starts to make sense but not nearly there yet.

Or perhaps a smart plan comes along with a decent night time window and a low rate but then you lose your CEG and sell the excess to the grid which makes increased storage unviable again.

Doesn’t really seem like the environment to drop another 5k on an off the shelf battery. So it’s Diy or hold off and see what comes. Wife’s says no to DIY as it’s in the utility :-(. So for me it’s wait and see.

I think I’d be better served with a second small install on a south facing garage we have and add 2-3kwp with a standard inverter to my winter generation. Then again it’s hard to say the maths work for that either.

Harika

After your installer uploaded the documents to the SEAI, do you get any feedback on that? Mine were uploaded two weeks ago and I see them at the portal but no further info on next steps or if something would be missing.

micks_address

https://www.boards.ie/discussion/comment/120457584#Comment_120457584

Mine was same.. potentially ber is outstanding... Annoyingly it doesn't track the ber there.. after approved for payout seai sent an email

con747

https://www.boards.ie/discussion/comment/120457584#Comment_120457584

I received an email from the SEAI because some information was missing and got my installer to resend what they asked for. Make sure you check with ESBN that they received your NC6 though, they lost plenty and people lost out on FIT payments. I got them to send me an email confirmation as proof.

JayBee66

https://www.boards.ie/discussion/comment/120457584#Comment_120457584

Be prepared for a long wait. Especially, if you get a visit from the SEAI Inspection Nazi, as we had. Installed February of last year, Nazi arrived in April of last year. Installer then had to make changes; rerouting of cables and yet more labels. Payment about two months later.

Harika

Thanks for the info. Ber is done and esb confirmed nc6 is done.

Have three weeks left on the six months Seai deadline as installer took three months to upload information after several phone calls and emails.

unkel

https://www.boards.ie/discussion/comment/120457353#Comment_120457353

I'd have thought that with a 10kWh battery you could have a far lower percentage on day rate?

redmagic68

Possibly

https://www.boards.ie/discussion/comment/120459637#Comment_120459637

I’m running a heatpump , mhrv and electric cooking etc so all electric house. I went worst case scenario for the prediction. Only have the solar install since December so the next few months will tell a lot more. To completely come off peak rates year round I’d probably need another 5-10kwh battery. Currently only have 7.7kwh useable with base load of 0.46kwh.

unkel

You'd need a lot more than another 10kWh to completely come off peak rates, believe me 😁

yankinlk

Waiting until the first full season goes round is a great strategy. So many unknowns when you try and predict both usage and output.

What about...

Government bonus

Rates going up or down

FIT ... Where is it going next

Ability to Load Shift a bit more

Battery prices

I made it thru a full year paying only 30 euro for my usage. Id love to say it was zero but to buy the battery to get to zero would have cost a LOT more, in my eyes a bad investment FOR ME. Next year if things change i might still expand battery. I said the same a year ago.

redmagic68

https://www.boards.ie/discussion/comment/120460370#Comment_120460370

Coming completely off day isn’t likely or cost effective I don’t think. Unless battery prices hit the floor but based on what has happened so far with the systems since December and how we use power, 20kwh battery storage would see our house well along to needing almost 0 day time units most of the winter.

I’ve the heat pump running to space heat and do hot water solely on the night rate. All machines running on night rate also. Daily base load is 7kwh, so 8kwh more would pretty much cover the remaining daily use in winter regardless of production.

Would the outlay on the extra battery pay for itself in a reasonable time….. to soon to say. As @yankinlk suggest above I’ll do nothing without more data. The system was over €14k so until I see some decent payback on it there will be no more investment.

Im very much for helping to improve the countries green energy and trying to leave a planet behind me for the future but the sums have to work in terms of money.

An ev is on the agenda in the future and that’ll be where funds will probably be directed but the money tree is pretty bare at the minute and the wife’s 16 year old Corolla is still rocking so a change is well down the road. I do the most driving for work so I will give her my car eventually and buy an ev with range for at least two work days without charging (300km plus) and hopefully a battery that supports the house.

who knows what’s completely right in any situation as the technology changes and different directions and scenarios seem to appear all the time. So if anyone’s crystal ball is clearer than mine I’d love to get opinion on what to do or where to go next

I do think it’s stupid though that there isn’t some government support for domestic batteries. They could easily act as a grid support during peak events and balance the grid. Also reduce the need for daily production when balanced with a Pv system. A 5kwh battery should be standard with domestic installs in my opinion for the reasons above but obviously the cost on people prevents this.

Busman Paddy Lasty

https://www.boards.ie/discussion/comment/120460998#Comment_120460998

Insane to have gotten rid of the battery grant in my opinion.

I've a 1.7 south array and 1.4 west so I can't reliably run appliances on solar without battery discharge. Have already a had a <1 kWh import day, all meals cooked and washes done that day. Not possible at all without battery and it has exceeded expectations so far.

The battery can keep us off peak time, not the panels, from March to end of October which is what the Green morons allegedly want.

bullit_dodger

+1 on that, and the name of the thread is "solar for dummies" - seems somehow apt for the policy makers.

I remember thinking that very point Busman when they got rid of the €600 battery grant in Feb '22 - that it's EXACTLY the technology to help with deal with peak demand. Sure smart meters penalizing consumers helps migrate load to "some" extent, but it's hard in the middle of winter at 6pm when the kids are looking for food to shift that load.

Disappointing.

unkel

Yep. All this country needs for electricity needs is solar + wind + BATTERY

The latter being the most important of the three. Note you can have batteries in many different forms if you use the wider definition of the term. Pumped hydro, chemical batteries, interconnectors, etc.

Run and Skip

Live in an A2 rated house in South Wexford. House is heated with A2W heat pump and underfloor heating. Have a 2kW solar PV array. I think the inverter is 2kW. Have a day and night electricity meter. We have 2 electric vehicles which we charge on night rate. We are away at work for most of the day. Following a few whoppers of electricity bills over the last few months we are exploring our options.

We also have a second house in West Cork that we mostly use in the Summer months and is only infrequently occupied from September to March. It has oil-fired central heating. It has a South facing rear roof with plenty of space for solar panels (granted, it is not as sunny there). It has a smart electricity meter.

Trying to figure out where we would get the most bang for our buck. Should we be focusing our attention on expanding our solar in the main house and looking at a battery and possibly micro-generation or might we be better off putting solar into West Cork with the intention that for a good part of the year, most of what we produce would be exported to the grid?

All suggestions are appreciated.

Busman Paddy Lasty

https://www.boards.ie/discussion/comment/120461799#Comment_120461799

It is silly indeed as smart meter rollout with peak charging will hurt people in the pocket and give a higher vat yield to government. The battery grant needs to come back, even though it would be short term as grants are tapered down to nothing.