Domestic solar PV quotes 2018

Padre_Pio · 16-09-2019 7:08pm

bunderoon wrote: »

The sensors are just cheap Aliexpress ones
I taped them up a little to make sure that the ends done come off and used a wire from a coat hanger to slide the end in to the sensor cavity in the cylinder.
Works perfect for what I want for the moment. I will get proper ones one I know which way I am going to go.

I have these for the past two years, still going strong on the same battery.

garo · 16-09-2019 11:21pm

Most batteries are rated for 6-10,000 cycles. You may get 25,000 cycles are greatly reduced capacity but I think it is safer to assume 10k cycles at 90% discharge. Do you know the make of the battery you are going for?
So a Pylontech 2.4kWh will give 2.2kWh per cycle at ~90% DoD. Times 10k cycles gives you 22MWh. At a cost of 1300 off eBay shipped you are talking 6c per unit just to use the battery. Charging at a night rate of 8c you basically save about 2c max. Not worth it IMO.
Yes these days you will get a 5 KWh battery to last until midnight. But for 3-4 months in winter you probably won’t be able to get them fully charged. It’s about whether to go for a small 2.4kWh battery or a larger 5kWh one. I went for a smaller battery and am willing to wait for a FIT or 25% cheaper batteries in 2-3 years. You may decide otherwise.

unkel · 17-09-2019 12:06am

garo wrote: »

It’s about whether to go for a small 2.4kWh battery or a larger 5kWh one.

There are options in the middle as well, which (given the €3,800 subsidy) might be the sweetest spot. I'm thinking the Pylontech US3000 (3.5kWh)

The big benefit is that it can charge / discharge 50% faster than its little US2000 brother. Makes a big difference when a cloud is passing over and you have a few appliances on. The difference between buying from the grid at peak rates, or taking from your battery.

garo · 17-09-2019 10:58am

Yes agreed. I find the 2000 with a max discharge of 1240W is not enough when the oven is on. On eBay the 3000 was almost 50% more expensive so return on cost is pretty linear. And I would rather spend that 500 euro on the bigger battery than an Eddi as I use Nat gas for HW.
So unkel you are not going for a 2 ton lead acid bank then?

Alkers · 17-09-2019 11:16am

AidenL wrote: »

The battery seems to be around 3000 including VAT, less the grant? Hard to see exactly how much it is in the quote, I got a lump sum price. So that would be 2k nett, divided by 0.08 - so 25,000 cycles? Is that correct?

Or am I doing the calls wrong?

25,000 cycles - even if you were cycling the battery four times a day (which you won't) it would be nearly 20 years before the battery breaks even.

AidenL wrote: »

Would the battery not cover say, from 8pm these days till midnight, with a saving on day rate if it was fully charged on a bright sunny day like this? And then night rate overnight at 8 cents? And back to recharging the battery tomorrow?

What am I missing? Im not sure what the saving would be on a smaller battery.

The smaller battery would likely cover you most of the way to midnight until the night rate kicks in so it's saving you your day unit price and pays for itself reasonably quickly given the grant.
The larger battery will likely have capacity left over so rather than saving you day rate, you're only saving 8c/unit which makes the payback for the battery so long.

AidenL wrote: »

And in winter, is it not sensible to charge the battery overnight at night rate and expend it during the dull winter mornings?

The finances don't always make sense even when charging the battery for free, they almost never make sense when you're paying to charge the battery (even at night rate).

unkel · 17-09-2019 8:27pm

garo wrote: »

So unkel you are not going for a 2 ton lead acid bank then?

About half a ton (16 batteries of nearly 30kg each), but yes, lead acid!

20kWh :cool:

Waiting for a waterproof cabinet that was supposed to come my way, before I can build the battery and have the other components all hooked up.

Winterman1234 · 18-09-2019 11:23am

Long time following this thread, but first time poster. After sitting on the fence over this past few years I think i am going to take the jump with a PV installation.

I have received a few quotes with prices that vary quite alot. But one of the more favorable quotes was for a 2.4kw array and solis dual 2000 inverter and 2.4kw polytech battery.

Personally I would be looking to increase array size to over 3KW, which would require a higher power inverter?

Total novice question but what is the difference between dual inverter and hybrid, should i not have been quoted for a hybrid inverter to use with the 2.4kw array and polytech battery or can the solis dual 2000 inverter be used to charge battery.

unkel · 18-09-2019 11:39am

Winterman1234 wrote: »

Total novice question but what is the difference between dual inverter and hybrid, should i not have been quoted for a hybrid inverter to use with the 2.4kw array and polytech battery or can the solis dual 2000 inverter be used to charge battery.

Dual means the inverter can handle 2 strings of solar panels. You need this if you have 2 different arrays in different orientations, say x panels east facing and y panels west facing

For use with a battery, your inverter needs to be a hybrid, so yes you should have been quoted for that

Also, if you are going for the grant scheme, I would go for a 4kW array as the extra panels over a 2.4kW array will cost about the same net to you (or even be cheaper) as you get an extra €1100 subsidy for this

The aim is about €6-€7k for a 4kW system with hybrid inverter and a lithium battery (net after the full €3,800 subsidy)

Kalyke · 18-09-2019 11:47am

Is the date for qualification for the grant written in stone? What I mean is, my house was completed in July 2006 (To shockingly bad standards in terms of insulation, air tightness etc) I am assuming my house would not be eligible for SEAI grants. Is there any wriggle room with the SEAI concerning the dates?

Winterman1234 · 18-09-2019 12:08pm

Thank you unkel for explaining this, the information from many of the registered SEAI installers is vague and more a sales pitch, when questioned about detail you get the feeling some don't fully understand.

The quote for 2.4KW JA array, solis 2000 tl inverter, eddi and 2.4KW polytech was €4500, I will question them on the inverter and try to get a more bespoke quote for the larger array. The same company for a 2.1KW JA array, solis 2000 tl inverter and eddi was €3300.

unkel · 18-09-2019 12:36pm

Kalyke wrote: »

Is the date for qualification for the grant written in stone? What I mean is, my house was completed in July 2006 (To shockingly bad standards in terms of insulation, air tightness etc) I am assuming my house would not be eligible for SEAI grants. Is there any wriggle room with the SEAI concerning the dates?

The house needs to be built and occupied before 2011 for the PV grants. So you are good there!

My own house was built in 2000 also to shockingly bad standards. Even at the time I got the impression you paid 90% of the value of the house for the land and the labour (at hugely inflated boom rates) and maybe 10% on building materials. Things have much improved in recent years.

phester28 · 18-09-2019 1:47pm

Winterman1234 wrote: »

Thank you unkel for explaining this, the information from many of the registered SEAI installers is vague and more a sales pitch, when questioned about detail you get the feeling some don't fully understand.

The quote for 2.4KW JA array, solis 2000 tl inverter, eddi and 2.4KW polytech was €4500, I will question them on the inverter and try to get a more bespoke quote for the larger array. The same company for a 2.1KW JA array, solis 2000 tl inverter and eddi was €3300.

I take it that those prices are after a grant rebate, on a tiled roof and single roof direction?.

Winterman1234 · 18-09-2019 1:57pm

Yes after grant, bunaglow with tiled roof and all panels on the same side. Location Donegal and company are northern ireland based and on SEAI register.

garo · 18-09-2019 3:28pm

Bungalow should be a cheaper install as scaffolding may not be required. Read through the thread for actual quotes and I would agree with Unkel. Aim for 6-7k for a 4kW system with a battery. Eddi is not strictly necessary as if you heat your water with Nat gas you won’t make your money back for a long time. PM me for info on a couple of installers.

unkel · 18-09-2019 5:24pm

+1

You save 5c / kWh if you have a high efficiency gas boiler, but you will likely get a similar FIT soon enough. If that happens, your investment in the Eddi (about €500 including fitting?) would have been a complete waste of money.

Winterman1234 · 18-09-2019 8:41pm

Not much gas here in rural donegal, we are using oil grant vortex. It was more for convenient during summer when oil is not in use. But yes you have a valid point.

garo · 19-09-2019 11:05am

Not sure about oil boiler efficiency so an Eddi or iBoost (which is cheaper) May make sense in your case as you get to keep the boiler completely off in the summer months. But to maximise you need to have a large well insulated cylinder. A 300l would be ideal as it would tide you over a dull day or two.

air · 19-09-2019 11:26am

Any boiler is likely to last a long longer if not used at all for 6 months of the year as well.
Many boilers (especially oil) don't modulate and their nominal output is going to be a lot higher than the achievable heat transfer rate into the hot tank.
This will lead to short cycling which means more wear and tear and likely further reduced efficiency.

A low cost alternative to a diverter would be to install a lower wattage immersion element and run it on a timer for a few hours during the summer. Should provide most of the benefits at a fraction of the cost, especially if the house is unoccupied during the day, like many are.

Another option is to pick up a cheaper diverter. I got one for a buddy for <€100 from eBay (2nd hand) and he is delighted with it.
They are easily retrofitted post installation.

garo · 19-09-2019 12:40pm

Good points all. Short cycljng will be an issue with most older boilers. Only newer condensing Nat gas boilers are able to modulate and even there not sure you have the option for hot water. A cheap diverter may be the way to go.

Winterman1234 · 19-09-2019 1:53pm

unkel wrote: »

Dual means the inverter can handle 2 strings of solar panels. You need this if you have 2 different arrays in different orientations, say x panels east facing and y panels west facing

For use with a battery, your inverter needs to be a hybrid, so yes you should have been quoted for that

Also, if you are going for the grant scheme, I would go for a 4kW array as the extra panels over a 2.4kW array will cost about the same net to you (or even be cheaper) as you get an extra €1100 subsidy for this

The aim is about €6-€7k for a 4kW system with hybrid inverter and a lithium battery (net after the full €3,800 subsidy)

To update quoted €6700 for 4.2KW array, solis 3.6KW hybrid inverter (had asked for 5KW though), 2.4KW polytec battery and hotwater diverter.

unkel · 19-09-2019 3:56pm

Winterman1234 wrote: »

To update quoted €6700 for 4.2KW array, solis 3.6KW hybrid inverter (had asked for 5KW though), 2.4KW polytec battery and hotwater diverter.

Decent enough quote. Get the 5kW inverter though, it only costs about €30-€40 more than the 3.6kW one.

air wrote: »

Another option is to pick up a cheaper diverter. I got one for a buddy for <€100 from eBay (2nd hand) and he is delighted with it.
They are easily retrofitted post installation.

garo wrote: »

A cheap diverter may be the way to go.

Don't these cheap older diverters not upset the grid with square modified sine waves? I recall quentingargan posting about them here.

air · 19-09-2019 4:54pm

unkel wrote: »

Don't these cheap older diverters not upset the grid with square modified sine waves? I recall quentingargan posting about them here.

The newer ones are definitely more elegant but he has had no issues in practice.
Experience may vary I guess. I only tested it myself for a few days but can't say I noticed any flicker or anything.

Like I said a 1000W immersion element and a timer or indeed something smarter could be a good low cost compromise solution.
Plenty of inverters and cheap monitoring systems with good reporting nowadays that could be used to switch a WiFi controller on once production or export reached a threshold.

garo · 19-09-2019 9:51pm

Arduino + IFTTT FTW?

unkel · 19-09-2019 9:58pm

air wrote: »

The newer ones are definitely more elegant but he has had no issues in practice.
Experience may vary I guess. I only tested it myself for a few days but can't say I noticed any flicker or anything.

Like I said a 1000W immersion element and a timer or indeed something smarter could be a good low cost compromise solution.
Plenty of inverters and cheap monitoring systems with good reporting nowadays that could be used to switch a WiFi controller on once production or export reached a threshold.

I looked into doing something similar for trickle charging my car (EV) based on light sensors. All quite doable and with a higher reward than water heating, but even less practical than an immersion diverter as it would involve having to use my granny cable, not my normal dedicated and secured EVSE charger and of course having to plug the car in all the time.

Meh. I'll just force myself to be patient and wait for a FIT. And build a big fook off battery

air · 19-09-2019 10:08pm

garo wrote: »

Arduino + IFTTT FTW?

Wouldn't even need an Arduino I suspect, plenty of monitoring solutions that could be used.

Yes unkel, certainly easier and cheaper than the EV equivalent.

bunderoon · 19-09-2019 10:13pm

unkel wrote: »

I looked into doing something similar for trickle charging my car (EV) based on light sensors. All quite doable and with a higher reward than water heating, but even less practical than an immersion diverter as it would involve having to use my granny cable, not my normal dedicated and secured EVSE charger and of course having to plug the car in all the time.

Meh. I'll just force myself to be patient and wait for a FIT. And build a big fook off battery

We're about to replace a 80kw UPS at work in the next two weeks. Took a look inside. 12v 40Ah batteries... lots and lots of them....I've no renewables at home but seriously thinking of taking as many as I can

unkel · 19-09-2019 10:21pm

Go for it! You don't need to have a solar PV system to use batteries. You can get a grid attached battery inverter like the one I got, the Sofar Solar ME3000SP. I paid GBP400 for mine including shipping. Not cheap but the payback time should be very short as I can load it up every day in summer with my PV And in winter with cheap 8c night rate electricity. The inverter needs to be connected to your consumer unit (with its own RCBO) by an electrician but the rest of the setup can be done DIY. Comes with built in wifi and a phone app that shows you at anytime how much you are importing or exporting to the grid, how much your solar is producing and how much you are charging / discharging the battery. Pretty cool.

Those batteries are most likely some form of lead acid. Only have the rated capacity of lead acid is usable so get as many as you can. Mine will be 20kWh (half of that usable). So take loads of them

unkel · 19-09-2019 10:25pm

bunderoon wrote: »

We're about to replace a 80kw UPS at work in the next two weeks. Took a look inside. 12v 40Ah batteries... lots and lots of them....

40Ah * 12.5V = 500Wh

80kWh / 500Wh = 160 batteries

garo · 19-09-2019 10:42pm

unkel wrote: »

I looked into doing something similar for trickle charging my car (EV) based on light sensors. All quite doable and with a higher reward than water heating, but even less practical than an immersion diverter as it would involve having to use my granny cable, not my normal dedicated and secured EVSE charger and of course having to plug the car in all the time.

Meh. I'll just force myself to be patient and wait for a FIT. And build a big fook off battery

Didn't rolion figure out a way to charge his car using the excess? I defo plan on rigging something up once I get an EV. My car will be home during the day most of the time.

listermint · 19-09-2019 10:44pm

garo wrote: »

Didn't rolion figure out a way to charge his car using the excess? I defo plan on rigging something up once I get an EV. My car will be home during the day most of the time.

He did.

Popping down to the local ESB charger during the day

unkel · 19-09-2019 10:50pm

garo wrote: »

Didn't rolion figure out a way to charge his car using the excess? I defo plan on rigging something up once I get an EV. My car will be home during the day most of the time.

You can buy chargers that can do that, like the Zappi. I already have a charger that was installed for free (previous scheme) and to replace it with something like the Zappi which starts at €750 + install costs would never pay for itself.

The (realistic) aim of my home attached battery is to reduce to a minimum the high rate electricity I buy from the grid all year round. I don't mind so much buying 8c electricity from the grid at night when it is at the most environmentally friendly time to use grid electricity. And to be honest, I don't really care about my PV overproduction going back to the grid for free. Call it part of my contribution to revert climate change. That plus my family car being an EV and having 40 solar thermal tubes for my hot water. Limit flights and try eat a bit less meat.

garo · 19-09-2019 11:00pm

Really? I assume it would pay for itself once the E600 grant is taken into account. There was all this talk about the Eco++ mode doing this on one of the threads.

unkel · 19-09-2019 11:42pm

garo wrote: »

Really? I assume it would pay for itself once the E600 grant is taken into account. There was all this talk about the Eco++ mode doing this on one of the threads.

People are paying typically about €1,100 or more for a Zappi install, so still €500 after the grant (while you can get an install done for €0 after the grant)

A kWh charging your car costs 8c

So this extra €500 would need 500 / 0.08 = 6MWh sent to the car before it pays for itself. If I could charge up my EV 100% from the Zappi for 5 months of the year (pretty unrealistic), it would still take nearly 10 years to pay for itself. By which time it would be dead.

With a FIT of 5c the pay back time would be more like 25 years

And in my case, I already have an EVSE, so it makes zero financial sense to replace it with a Zappi or other intelligent charger. These things look great on paper, great idea, but maybe for people who love their ideas of being green, and don't have to worry too much about how much it is going to cost them...

DrPhilG · 21-09-2019 11:07pm

Energia bill arrived yesterday, €279.

wexfordman2 · 22-09-2019 2:31am

DrPhilG wrote: »

Energia bill arrived yesterday, €279.

How long for, and showing is your system up and running ?

DrPhilG · 22-09-2019 3:58pm

wexfordman2 wrote: »

How long for, and showing is your system up and running ?

2 months. 2 summer months.

I haven't got solar yet. Have priced a few options but haven't bit the bullet yet.

garo · 22-09-2019 6:09pm

I submitted my meter read today. The estimated bill is €60. The previous one was €154. Got solar about halfway through the billing period.

Stefs_42 · 22-09-2019 8:11pm

garo wrote: »

I submitted my meter read today. The estimated bill is €60. The previous one was €154. Got solar about halfway through the billing period.

thats exactly in line with my current bills now. my average bills were in region of 160 e, now dropped to 60 e. but thats only summer months. i dont think winter will provide same results

garo · 22-09-2019 9:00pm

Absolutely. I was given a seasonal modelling chart that shows the decay thus in terms of number of kWh produced per day per kWp installed:

Aug: 3.2
Sep: 2.4
Oct: 1.4
Nov: 0.7
Dec: 0.45
Jan: 0.55

So we are talking a bit of over 2kWh per day in Jan for me.

unkel · 22-09-2019 9:07pm

That's interesting, have you data for all 12 months?

wexfordman2 · 22-09-2019 10:47pm

garo wrote: »

Absolutely. I was given a seasonal modelling chart that shows the decay thus in terms of number of kWh produced per day per kWp installed:

Aug: 3.2
Sep: 2.4
Oct: 1.4
Nov: 0.7
Dec: 0.45
Jan: 0.55

So we are talking a bit of over 2kWh per day in Jan for me.

Aug and sept looks low based in what I am.seeing. 6kwp installed, so that would mean average of 18kwh for aug, and I reckon I had an average of 25kwh. And to be honest, weatherwise, Aug was poor.

Interesting though

garo · 22-09-2019 11:59pm

I do. Note this is for an E/W orientation 50% on each side. If you have a South facing install your total power would certainly be higher. Here's the full year (apols for formatting):

January 0.60
February 1.16
March 2.09
April 3.25
May 4.12
June 4.12
July 3.77
August 3.30
September 2.47
October 1.46
November 0.76
December 0.46

I got 3.28 August average for the second half. I am getting 2.86 for Sep so far.

Note the numbers in my initial post were guesstimates reading off a chart. I got the actual numbers for this post.

unkel · 23-09-2019 12:08am

They clearly are for an E/W setup

Imagine May producing more than July or August! The total figure seems to be a bit optimistic for E/W, 3.53MW/h for a 4kwp setup. Who gave you those figures?

garo · 23-09-2019 12:19am

I got these from my installer based off their simulation model. Specific to my orientation - which isn't exactly E/W but off by a few degrees and my roof's tilt angle. So I assume it will vary for other people. These are obviously very generic numbers based on average hours of sunshine. In a year's time we can look at how closely we matched. May > August is not that surprising as May is closer to the solstice and generally has more hours of sunshine.
Google global horizontal irradiance solar model

unkel · 23-09-2019 12:25am

I guess you can come back here on the first anniversary of your system and tell us if it did make the 3.53MWh (your system is 4kwp, right?)

I'll do the same, but I expect my 3.8kwp in sunny west Dublin

(limited by my 3.6kW inverter) S/W (but mostly south) to have generated close enough to 3.6MWh, possibly even a bit more.

wexfordman2 · 23-09-2019 7:51am

garo wrote: »

I do. Note this is for an E/W orientation 50% on each side. If you have a South facing install your total power would certainly be higher. Here's the full year (apols for formatting):

January 0.60
February 1.16
March 2.09
April 3.25
May 4.12
June 4.12
July 3.77
August 3.30
September 2.47
October 1.46
November 0.76
December 0.46

I got 3.28 August average for the second half. I am getting 2.86 for Sep so far.

Note the numbers in my initial post were guesstimates reading off a chart. I got the actual numbers for this post.

Doh!

Sorry, hadn't thought that through, was looming st it being more of a generic figure, but of course it has to be specific to the system design, etc.

KAGY · 23-09-2019 8:17am

Here's a site with a sizing calculator. http://www.calculationsolar.com/calculate.php

Badly translated from Spanish using Google translate, but it give an idea of the efficiency of the systems (they sell)

rolion · 23-09-2019 8:23am

Good reports,great systems,happy owners...
Hold your optimism for the winter months and i will chat again in spring 2020.

Batfink69 · 23-09-2019 9:02am

Batfink69 wrote: »

Hi All,

Just bought a 2.7kw system; no battery or grant and hoping to self install mostly myself to keep costs down. It's a bit of a trial really as I'm fitting it on my garage roof where I do get a bit of shadow. I've paid the extra and gone for Optimisers, iBoost+ and Buddy so excess electricity can go to the Immersion heater. The 'Buddy' will tell the wife, who's at home most of the day, when we're exporting so she can go around the house turning all the lights on (oh, she does that already!).

I'll get to the point. I'm quite hands on but would like to get a look around someone else's system for various pointers and tricks so I don't look at it for the next 20 years thinking how differently I wished I'd installed it.

I'm Donegal Town based and would love to have a look at another install as locally as possible. Many thanks to all in anticipation.

Bren.

Bump...Don't mind travelling a bit to pick up some hints and tips if someone wouldn't mind me having a look around their setup?

Thanks all, Bren

garo · 23-09-2019 12:39pm

I am in Dublin so no use to you. But would have been happy to show you everything otherwise.

Domestic solar PV quotes 2018

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