Domestic solar PV quotes 2018

unkel · 06-02-2019 10:16PM

niallers1 wrote: »

If bright out the panels could generate most of the 3kw needed but even if they didn't the battery would supply the short fall.

If the battery is charged. And don't discount the base load of the house that runs in the background. That could also easily be a few hundred watt.

I have a similar issue with my car. As a default it charges at 7.2kW. Which even with the sun blasting down, would cost me more to charge partially from the grid, than it would cost me to charge at the night rate. Pointless. There is a setting in the car that I can charge at medium or at low rates. I have to find out what they are but I believe the low rate is just 6A (so about 1.4kW). That would do nicely on sunny days

niallers1 · 06-02-2019 10:18PM

unkel wrote: »

Because instead of using the diverter, you can heat your water with an efficient gas or oil boiler (if you have one), which costs about 4c/kWh

In a similar vein, charging your car (or running your dish washer) is worth 8c/kWh because instead of with solar PV, you could charge your car at night at the night rate, which costs 8c/kWh

The one thing that makes me disagree with this a bit is in my case I'd have to put a price on sleeping well. Putting on the appliances in my house at night is very noisy. I wouldn't be able to sleep properly.

unkel · 06-02-2019 10:20PM

Aye that's fair enough. If you never put on your appliances at night even though you do have night rate electricity, then running them on solar PV is worth the full 17c/kWh or so day rate to you

niallers1 · 06-02-2019 10:52PM

unkel wrote: »

Aye that's fair enough. If you never put on your appliances at night even though you do have night rate electricity, then running them on solar PV is worth the full 17c/kWh or so day rate to you

I don't have night rate yet. Luckily I get to charge the car at work but if that changes then I'll have to get it in to charge from home at night.

unkel · 06-02-2019 11:06PM

Yeah if you rarely charge the car at home and prefer not to switch on hungry appliances at night, there's no point in getting a night meter.

I take it your battery is on the DC side (hybrid solar inverter)? In that case there probably isn't any way to program the inverter to charge the battery up during the cheap night rate anyway?

This is the main reason I want the battery on the AC side. And of course I had no appetite for paying mad money for a hybrid inverter. No PV subsidies yet for this boyo, it had to be mostly DIY and getting parts cheaply here

KCross · 06-02-2019 11:14PM

zdragon wrote: »

I don't consider a system without battery. spending couple of thousands just to give away free energy, doesn't make sense at all

You'll need to look closely at the math on that.
Battery storage systems, even with the €1k grant, have a long payback time.

A battery storage system requires...
- hybrid inverter... about €800 extra
- labour costs... i was quoted €300 extra in labour/cabling etc to add it
- battery itself - ~€1200+ for the smallest battery - 2kWh
- minus the €1k grant.

Add that up and then figure out what the payback for you would be and you need to be realistic about how often you will have excess to send to the battery as there will be several months where there will be nothing.

A 2kWh battery is tiny really and the warranty on them is about the same timeframe as the payback.

Do your research is all I'd say.

unkel · 06-02-2019 11:27PM

Agree with your post KCross, but:

KCross wrote: »

- hybrid inverter... about €800 extra

Instead of going battery on the DC side, you can go AC side. Which requires a battery inverter which costs about €300-€400

With the added benefit that you can cycle your battery at night rate every night too. Giving you 365 cycles per year * (17c day rate minus 8c night rate) * 2.4kWh battery capacity for a small batttery, or €80 per year, which might halve your payback time of this €800 system (your figures of 800 + 300 + 1200 -/- 1000) adjusted for the cheaper AC option) from 10 to 5 years

rolion · 06-02-2019 11:35PM

One reason why will not have a FIT payment is...why to pay the "home supplier" when we can get it for free !??
Forgot to switch on the diverter today... 6KWh went to unkel's favourite battery: grid... hmmm

After reading last few posts,just enabled timer for the spring time ...not too happy to give for free,sorry !

KCross · 06-02-2019 11:36PM

unkel wrote: »

Agree with your post KCross, but:

Instead of going battery on the DC side, you can go AC side. Which requires a battery inverter which costs about €300-€400

With the added benefit that you can cycle your battery at night rate every night too. Giving you 365 cycles per year * (17c day rate minus 8c night rate) * 2.4kWh battery capacity for a small batttery, or €80 per year, which might halve your payback time of this €800 system (your figures of 800 + 300 + 1200 -/- 1000) adjusted for the cheaper AC option) from 10 to 5 years

We've been here before unkel!

I'm still not convinced Joe public will get the cycles you suggest. If you charge it up at night, will you have it burned off by the time the excess sun appears?

Or will you just have a winter/summer switch to go from AC charging at night during winter to excess sun during summer?

I just think anyone considering it needs to take a critical look at the figures and not convince themselves it will pay for itself according to the sales literature.

If you can make it work, great, go for it.

I remain to be convinced based on the quotes I've got.
I'll take another look at AC connected systems and see if I can convince myself!

unkel · 07-02-2019 12:38AM

As before, I don't really disagree with any of your points. And it's hard to make the case either way without hard evidence, which is nearly impossible to measure. Unless you spend silly money on being able to measure

KCross wrote: »

If you charge it up at night, will you have it burned off by the time the excess sun appears?

That is a key question. I presume you will, easily enough outside the 3 or so summer months. On the longest day of the year? Maybe. And my presumptions are only based on the smallest battery size

Maybe if we put a timeline on it. Battery fully charged by 01:00. House base load 240W. By 08:00 (even on the longest day there would not have been that much useful PV by then), the baseload has already taken 7*240/2400 = 70% of the full battery charge. By 10:00 or 11:00 except maybe on the very brightest, longest days, you will have cycled your battery in full

Sounds pretty convincing doesn't it?

unkel · 07-02-2019 12:43AM

rolion wrote: »

Forgot to switch on the diverter today... 6KWh went to unkel's favourite battery: grid... hmmm

Haha, I tolerate excess PV production going into zero emissions vehicles too

I had a look at my inverter at 2:40PM, just over 8kWh generated. My system is 3.8kwp, 75% south and 25% west

None of that gone to the grid, to the immersion or to my EV

rolion · 07-02-2019 09:13AM

And,as below,that's "bad planning" on using the Sun's PVs.
Good coverage of the daily backgroound consumption but once night settles in, people arriving and using electrical appliances,all goes out of planning.

If we could invent PVs that works at dawn, as well !?
Or,improve the usage but HOW !?

Seanp92 · 07-02-2019 09:57AM

Hi All,

Looking at getting a 4.2kw system installed with 5kw battery but have been told that it’s either battery storage or immersion diverter, you can’t do both together. Is there a way of utilising both and have excess charge batteries and also divert some to immmerion ?

Cheers

rolion · 07-02-2019 10:04AM

Seanp92 wrote: »

Hi All,

Looking at getting a 4.2kw system installed with 5kw battery but have been told that it’s either battery storage or immersion diverter, you can’t do both together. Is there a way of utilising both and have excess charge batteries and also divert some to immmerion ?

Cheers

Get a 9Kw installed power PV array then it will be enough harvesting work for both battery and diverter.
...or...
get a 30 tubes solar / 300l cylinder and the quoted PV array.

Nice grants for both.

KCross · 07-02-2019 10:57AM

unkel wrote: »

Maybe if we put a timeline on it. Battery fully charged by 01:00. House base load 240W. By 08:00 (even on the longest day there would not have been that much useful PV by then), the baseload has already taken 7*240/2400 = 70% of the full battery charge. By 10:00 or 11:00 except maybe on the very brightest, longest days, you will have cycled your battery in full

Sounds pretty convincing doesn't it?

No, it doesnt!

Unless I've missed your point completely.... In the example you give above all you have done is shifted some of your night rate electricity from one hour to another(or at least for the 70% portion).... no net gain there!

What you need is to have the battery fully charged just as night rate finishes.... THEN start discharging it where you get the benefit of the cost differential between day and night.

The gotcha is that the sun is coming up when the night rate finishes so just as you start to generate free Solar your battery is full to the brim.

Technically you can make a battery pay for itself in reasonable timeframe but it requires micro-managing of when its charging/discharging and micro-managing your usage (turning on appliances when there's excess etc).

Personally I've no interest in a system that requires me to live my life around the system. It has to fit in seamlessly and just work and save me money in a reasonable timeframe.

wexfordman2 · 07-02-2019 11:44AM

Seanp92 wrote: »

Hi All,

Looking at getting a 4.2kw system installed with 5kw battery but have been told that it’s either battery storage or immersion diverter, you can’t do both together. Is there a way of utilising both and have excess charge batteries and also divert some to immmerion ?

Cheers

Mm,

Technically it is possible, and that's what I have been quoted for, albeit with a slightly bigger pv system (6kwp with 5kw inverter and battery etc).

The way I see it, during a good day, if my base load is 400w, I can at times be generating up to 5kw, so 4.5kw there to go to battery charge and immersion diverter. Maybe I am missing something but technically I can see why it can't or shouldn't work, the issue is more around usage etc.

KCross · 07-02-2019 11:54AM

Seanp92 wrote: »

Hi All,

Looking at getting a 4.2kw system installed with 5kw battery but have been told that it’s either battery storage or immersion diverter, you can’t do both together. Is there a way of utilising both and have excess charge batteries and also divert some to immmerion ?

Cheers

Its really down to the cost of those systems. The hot water diverters tend to be in the order of €500 to get/install.

You'll heat ALOT of hot water for that €500 via gas etc.

Technically you can put up so much Solar PV and batteries and diverters that you can go off-grid... the sticking point in all cases is making it work financially.

wexfordman2 · 07-02-2019 12:09PM

KCross wrote: »

Its really down to the cost of those systems. The hot water diverters tend to be in the order of €500 to get/install.

You'll heat ALOT of hot water for that €500 via gas etc.

Technically you can put up so much Solar PV and batteries and diverters that you can go off-grid... the sticking point in all cases is making it work financially.

So, it's down to whether or not it pays back or not.

It's interesting, when I was getting my quotes, everyone quoted me for a base system of 4kwp, 3.5kw inverter, 5kwh battery and an eddi hot water diverter, so they were all plugging the same configuration pretty much. Payback as you said, is the question.

For me, the payback for the eddi I suppose would be to see how much it cost to heat the hot water with oil v solar, I suppose bearing in mind that the excess solar won't just heat it once during the day, but would keep it topped up as well ?

Ant idea how much the cost if heating a 300l hit water tank with oil is ?

rolion · 07-02-2019 12:16PM

Just dont get it... help me.

Why not go for a standard quoted PV,with only array and battery !?
Then,apply for solar tubes grant AND the money difference versus bigger array + diverter and makes it more viable so that you have two independent systems !?
There are days when PV barely heats electronics while the solar tubes lifts the bottom sensor temperatures over 20ish.

dathi · 07-02-2019 03:01PM

wexfordman2 wrote: »

So, it's down to whether or not it pays back
Ant idea how much the cost if heating a 300l hit water tank with oil is ?

ltrs X 4 X temp difference /3412
incoming water 10* heating to 60*
300 X 4 X 50* / 3412 = 17.58 kwh + 10% for losses = 19.3 kwh
there are 10 kwh in 1 liter of oil . so two liters of oil

unkel · 07-02-2019 03:31PM

KCross wrote: »

No, it doesnt!

Unless I've missed your point completely.... In the example you give above all you have done is shifted some of your night rate electricity from one hour to another(or at least for the 70% portion).... no net gain there!

Duh, don't know what I was thinking there. Logic fail

Would need to have a look at the PV generation on a bright sunny day in summer between 9-11AM, but it might generate quite a bit at that stage, which would invalidate the night rate battery cycling argument. Well it would for the few summer months anyway on bright days. Should easily enough get a full cycle in the 6 months of winter time when night rate stops at 8AM I reckon, but this argument would bring the pay back period up a few years.

Unless you can cycle more than once on average during the day. Niallers1' data looks quite hopeful that way.

zdragon · 07-02-2019 10:37PM

unkel wrote: »

Because instead of using the diverter, you can heat your water with an efficient gas or oil boiler (if you have one), which costs about 4c/kWh

In a similar vein, charging your car (or running your dish washer) is worth 8c/kWh because instead of with solar PV, you could charge your car at night at the night rate, which costs 8c/kWh

the cheapest gas I've seen is 5 cents

zdragon · 07-02-2019 10:48PM

KCross wrote: »

Its really down to the cost of those systems. The hot water diverters tend to be in the order of €500 to get/install.

You'll heat ALOT of hot water for that €500 via gas etc.

Technically you can put up so much Solar PV and batteries and diverters that you can go off-grid... the sticking point in all cases is making it work financially.

I guess my maths are correct. stupid calculations tell me that even when all 4kw of solar is consumed , the payoff is 9 years. but real world distribution of generated solar concludes that solar is waste of money. as a household will never be able to consume efficiently what was generated on the roof.

unkel · 07-02-2019 10:49PM

zdragon wrote: »

the cheapest gas I've seen is 5 cents

Pedantic much? So it will save you 5c then instead of the "about 4c" I mentioned :rolleyes:

zdragon wrote: »

a household will never be able to consume efficiently what was generated on the roof.

I use every single kWh that my solar PV produces and my savings are fully at the higher rate too, can't get more efficient than that.

rolion · 07-02-2019 11:17PM

Guys..at this time of the day,you are wasting very valuable electrons typing things that does not makes sense...such as a PV array with a battery backup.

We will have to wait maybe another 3 years until those magic pieces of engineering called "deep cycle PV storage batteries" will be taken of the conspiracy theories benches and made public to all of us. But that will mean a big loss for some other industries so dunno... lets see where that path will take us... sorry for going offline on a offgrid topic !

randombar · 20-02-2019 11:11PM

Eddi on it's way! Will be interesting to see what this does for oil consumption (probably very little), but I'm all about the planet . . I swear

unkel · 21-02-2019 03:26PM

Has anybody got a list of or a link to the SEAI approved Solar PV installers handy?

spose · 23-02-2019 10:46PM

https://www.seai.ie/resources/find-a-registered-professional/Solar-PV-Installers-Register.pdf

New looking at PV and not much available roof space for more tha 2kw. Interested in why you say the Eddi isn’t going to last on a small set up

unkel · 24-02-2019 12:03AM

I found the list a few days ago, but thanks for sharing

spose wrote: »

New looking at PV and not much available roof space for more tha 2kw. Interested in why you say the Eddi isn’t going to last on a small set up

It will never save you the EUR500 it costs to install on a 2kwp system. The bigger your PV system, the more it saves. I'd say if you have a 4kwp system or bigger, it could be worth your while.

rolion · 24-02-2019 01:44PM

I'll say ..lets close the issue with PVs and the diverter.
There are three aspects that we can look at:

Technology,I can say is there, is mature and very reliable.
I'm talking about the few major players that have shops and back end support in Ireland and in UK
The devices are working, some of them have reporting, logging and web based applications while others just a small local display/

Sourcing the diverters, online and off the shelf available locations in Ireland and UK.
They are designed and certified to work on Irish grid networks and independent of the inverter.

Installation and cost
They can be done by any electricians or any DIYers that are confident.
A 20A RCB and appropriate cabling length, position beside the cylinder immersion element and the CT clamp in the fuse panel.
I advise to use rechargeable batteries in the transmitter.
Once received the device, I will say at a maxim of two hours charge and is in the place, configured and ready to divert.
While I don't expect an electrician to configure the monitoring and / or online logging side of the device, I will not be surprised to see the opposite ..or the owner to try doing itself, with the help of RTFM.

ROi / TCO

Will cost nothing for you to run it.
You will have manufacturer warranty standard on all products, that varies based on the device itself.
I will say the most cost that you will encounter is the owner looking at the reporting dashboard and seeing how the system performed today...

Morality of the diverter and human factors
Well, here some very pushing and convincing user(s) on the forum will start arguing about the kilowatt of electricity versus kilowatt power of the gas....diverter versus boiler.
I will just ignore it for now, nothing personal or short of the offence but I will ignore just for the pure sake of asking many times if the concept of gas boiler consumption and minimum modulation is well understood and explained. A 30Kw power is not .3c to heat or to run as that boiler will have factory preset parameters to crunch before firing the gas flame to the heat exchange.
So, based on that basic mechanical and numerical factors, I ignore the comparison

Not lastly, few days ago I forgot to set the timer for diverter. I had in that particular day almost 7KWh diverted for free to my neighbour fuse board and he paid the cost of 7 x .20c to the electricity provider and at all towards my PV system.
So, not being or saying anything wrong to SEAI and / or ESB, they are doing their economical living rationale as a company... but I just don't feel green enough with my own pocket cash to subsidy my street with free energy from my PVs.
So, as a battery storage solution is out of any logical conversation today (maybe tomorrow or the day after) I see only valid option to store that surplus on my own boundary, financial and moral. Why the "corporate" went against the FIT !??? Because they are counting on grants and the people to install tons of KW and get that surplus for free on to their networks and finally, to charge my street for the consumption, even in their books or on their reading meters that will be seen as a invalid surplus...imagine a LTD company having a surplus of thousands or euros in their bank account and being unable to explain to Revenue auditors the provenience or the where about... Free FIt for others.

For the past 30 days, a fifth of my generated PV energy went to grid for free, 200KWh produced and 50KWh exported. Only by my own errors that happened as I forgot to turn-on diverter scheduler for the good days,i have it off for winter as wasn't enough PV to have it on.
I don't really mind as the solar tubes will compensate for the diverter workings...

I can upload graphs and generated numbers but, let me ask you something first...
New owner of a subsidized PV system. Lets assume a standard 2 KW installed power, something similar.
It will cost you nothing to include the €400 now, at the time of the installation for the diverter, as you doing the mess in the house at the same time.

Now, will it be the same to spend over €500 after a month or six months or more !? NO
Will you feel comfortable knowing that "today", your system gives free energy ,whatever amount is it and you're losing it !? MAYBE

Whatever way you decide to heat it, your choice.
I've made mine 3 years ago and I never regret it.
I think I was the first with a diverter installed around here.
I have no shares or financial gains in diverters or gas boiler industries but just trying to make a case for common sense.
If FIT was there ,yes diverter may have become secondary to smaller systems. Or most of them.
But with "free" FIT to grid and no financial back-up pay to owner, even a 2 KW array summer time will get that cylinder working for free during day time with good harvest results. It goes back to your house. Goes back to your cylinder. Stays in back pocket. Saves owner bills.
Even if is only 8 months out of 12.

Have fun and be good.

Domestic solar PV quotes 2018

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