Solar PV - is it worth it?

eire1987

Latro wrote: »

I'm very skeptical about using any form of light to heat any house, even the best insulated one. In the winter the more heat you need the less light you get.

It is like having solar torch. It would work great in the sun when you don't need the light. Same with solar heating, maybe it would work in the summer but you dont't need the heat then.

Oh well, I don't have any experience with the system you mentioned so I can't give any valuable advice about it but it seems to be a bit tweaked evacuated solar tubes. As I said earlier, I'm skeptical.
If you decide to go with them please report back in the future.

Will do

denismc

To those of you suggesting diy are you electricians? as connecting an inverter and installing a new RCB to you fuse box is a probably a bit more than the average diy-er should attempt.
Also I would have thought installing an RCB and new circuit would require a registered RECI legally.
Not trying to be a killjoy, just a genuine question.

Shefwedfan

denismc wrote: »

To those of you suggesting diy are you electricians? as connecting an inverter and installing a new RCB to you fuse box is a probably a bit more than the average diy-er should attempt.
Also I would have thought installing an RCB and new circuit would require a registered RECI legally.
Not trying to be a killjoy, just a genuine question.

Electrician would have to install....But I plan to do all the roof work etc. Putting on the panels and then just have the electrician do the final 5%

unkel

+1

I would do almost all myself, but I would not open my consumer unit for any reason.

AndrewMc

Not sure if this has been answered already - are you still liable for the Low Usage Standing Charge if you get your PV setup gets your grid usage low enough?

niallers1

If you get your usage that low then yes.
The chances of being able to get that low would be low. Even at night when asleep you'll probably use a unit of electricity from fridge/ alarm / other appliances not fully switched off at plug.

AndrewMc

niallers1 wrote: »

If you get your usage that low then yes.
The chances if being able to get that low would be low. Even at night when asleep you'll probably use a unit of electricity from fridge/ alarm / other appliances not fully switched off at plug.

Our normal usage is about 6 kWh/day, maybe 7 in winter. When we're away it's 2. The low usage charge kicks in when you average below two. That's disappointing, I'd at least have thought you'd get an exemption when they're taking your excess solar energy for free.

KCross

unkel wrote: »

I think your own logic is flawed Kcross



True. At the moment. But with any investment, you need to look at the lifespan of the investment. Yes you might waste a few years of overproduction to the grid. You know I'm no fan of immersion diverters. But if you have a 4kwp system, they do begin to make sense. And what makes even more sense is to charge your EV. I know that is only worth 7c/kWh as you could charge your car at night, but it is like getting a 7c FIT. And then there is all this talk about a current utility company already paying a 6c FIT. And it is of course possible the state will implement a FIT to encourage the accelerated move to higher renewables. The longer view is that if you have a 40kWh home attached battery in say 5 years time, you won't have to pay any electricity at the higher rate anymore. In fact some people would no longer need to buy any electricity for say 250-300 days of the year :cool:

I've moved my reply over to this thread as I realised I was derailing the "quote" thread and this thread is better suited for the topic anyway(are batteries worth it)

I think you've argued against yourself there unkel.
If a FiT comes in (which I think is likely in the med-long term) it makes the case for batteries even less financially viable.

If you have a FiT then the battery is no longer displacing full day rate electricity. Its only displacing the difference between day rate and the FiT rate. The payback time will almost double in that case.

A FiT makes the need for batteries null and void. The grid is your battery and that is exactly what should happen if ESB Networks would allow it.

unkel wrote: »

But it makes sense now to benefit from the very generous €3,800 subsidy while still keeping your own spend to a minimum. This will to a large extend future proof your system, you'll only need to add batteries at some point, an easy job

Its a generous subsidy alright but generous doesn't necessarily mean it makes financial sense. I think it makes sense to install PV with the current grant but I don't think the batteries make sense.

Have you calculated any ROI yourself for the battery. What figures did you come up with? Please share.

I'm not fully sold on the future proof idea either even though I see some merit in it.
In, say, 10yrs time there will be better inverters and better batteries that might not be compatible with the battery you install today. So, it may not be a simple plug 'n play of a new module down the line. It might all be fine too but I'm not for taking the risk based on how new the market is.

For instance, can you simply add a new battery alongside a degraded battery? Will the inverter handle the imbalance? I dont know.

Are you tying yourself to one battery make/model and hoping that that is still on the market when you decide to expand.

Current batteries are primarily Li-ion. As we know from the EV forum there are likely to be new battery techs coming to the market in the next 5-10yrs (Solid state batteries are looking promising). Will you want to expand your degrading Li-ion "old tech" battery if there are new solid state systems going for less money, higher capacity, less degradation?


But primarily I'm not sold on the batteries because the payback is too long. It needs to be 10yrs or less, imo. It's closer to 20.

What payback time do you put it at? If we are in the same ball park then maybe we are on the same page just that you are willing to wait that long and Im not... which is entirely a personal decision.

niallers1

AndrewMc wrote: »

niallers1 wrote: »

If you get your usage that low then yes.
The chances if being able to get that low would be low. Even at night when asleep you'll probably use a unit of electricity from fridge/ alarm / other appliances not fully switched off at plug.

Our normal usage is about 6 kWh/day, maybe 7 in winter. When we're away it's 2. The low usage charge kicks in when you average below two. That's disappointing, I'd at least have thought you'd get an exemption when they're taking your excess solar energy for free.

6kw/7kwh a day is very good. Fair play.
I presume you have LED lights / LED TV and switch off appliances as much as possible.
Do you have any tips to get that low? Best we can manage is an average of 9kw per day over the year.

AndrewMc

niallers1 wrote: »

6kw/7kwh a day is very good. Fair play.
I presume you have LED lights / LED TV and switch off appliances as much as possible.
Do you have any tips to get that low? Best we can manage is an average of 9kw per day over the year.

Yes, all LEDs now except the last few surviving CFLs. Telly is about ten years old but we don't watch all that much. Switch everything off at the wall. A-rated washer and dryer.

Biggest difference is probably that we've mains gas for heating, oven and hob, and usually use the regular shower (heated by the central heating) rather than the electric. Gas is about a third the price per kWh compared to electric, iirc. In summer it's working out about 6kWh of gas per day for hot water and cooking.

unkel

KCross wrote: »

Have you calculated any ROI yourself for the battery. What figures did you come up with?

You're missing the point, there is no need to do a ROI calculation!

Neither of us know the future but it is almost certain batteries will become so cheap that installing large batteries will become the norm. And I very much doubt that todays inverters and batteries will be incompatible with the ones being sold in 3-4 years time. That wouldn't make any sense. An inverter is an inverter and a battery is a battery.

If you accept that, it might be a good idea if you are installing PV anyway, to make sure the system can handle a battery, given that you get a €2,400 subsidy for it. It is smart to use the cheapest battery possible because as you say, the ROI on them is bad

The €2,400 will pay for the battery, for the extra cost of the inverter and for the install. It is free. And your system is future proof

KCross

unkel wrote: »

You're missing the point, there is no need to do a ROI calculation!

If you accept that, it might be a good idea if you are installing PV anyway, to make sure the system can handle a battery, given that you get a €2,400 subsidy for it. It is smart to use the cheapest battery possible because as you say, the ROI on them is bad

The €2,400 will pay for the battery, for the extra cost of the inverter and for the install. It is free. And your system is future proof

I am definitely missing something if you think the battery is free! Explain that to me.
The grant for the battery is €1000. Why do you think its €2400 and hence free.
You can't allocate the grant for the panels against the battery. Thats man maths!

No matter what way you work it your quote will include a battery (€1350), labour (€300) and increased inverter costs (~€800-1000). Thats €2450 inc vat inc install. Less grant so thats €1450 net cost to you for a 2.4kWh battery. Thats what is in my quotes.

Show me a quote where a battery system is less than that?
You will be 15-20yrs breaking even on that €1500. Link

unkel wrote: »

Neither of us know the future but it is almost certain batteries will become so cheap that installing large batteries will become the norm. And I very much doubt that todays inverters and batteries will be incompatible with the ones being sold in 3-4 years time. That wouldn't make any sense. An inverter is an inverter and a battery is a battery.

I've heard otherwise. At least one company told me that the inverter was compatible with one battery and not another. I didn't delve into the detail of that. Maybe its BS but I can't see why they would need to make that up. I will ask more questions on that one.




You also didnt address my point about the FiT making the payback term even longer and you seemed to be putting FiT forward as a reason to add batteries which makes no sense. If you think FiT is possible in the near term it makes spending money on batteries now a bad investment. Do you agree or disagree that FiT would make having a battery a waste of money?

unkel

I agree batteries are a complete waste of your money right now. And I did state that you should only go for the battery if you are going to install PV anyway under the SEAI scheme. The extra cost of installing 14 panels (4kwp) over 7 panels (2kwp) is 7 panels * EUR148 plus say €300 in additional materials and labour. I've been there myself. Once you're on the roof, you're on the roof. A few more hooks and a few more rails and a few more clamps makes very little difference in your effort.

So €1450 plus VAT. But you get €1400 subsidy for this. But you have to get the battery, so get the cheapest 2.4kWh one for €950. If you accept that you will eventually go battery, you will have to pay for the hybrid converter at some point. So the cost of that isn't relevant in the calculations (and even if they do come down in value, it is probably easier to install a hybrid one now rather than a conventional one now only to have to change in a few years, get the sparks back in, try to sell your out of date conventional inverter that's almost worthless, etc). So going the extra 2kwp costs about €400 incl VAT and going the battery costs about €500 incl VAT.

Look, no matter what way you rig the sums, you'd be insane to install a 2kwp system under this subsidy regime. Either do a cheaper install using your own installer or DIY and your own parts (nothing to do with SEAI), but if you are going the subsidy route, the optimal choice is 4kwp plus tiny battery

KCross

unkel wrote: »

I agree batteries are a complete waste of your money right now. And I did state that you should only go for the battery if you are going to install PV anyway under the SEAI scheme. The extra cost of installing 14 panels (4kwp) over 7 panels (2kwp) is 7 panels * EUR148 plus say €300 in additional materials and labour. I've been there myself. Once you're on the roof, you're on the roof. A few more hooks and a few more rails and a few more clamps makes very little difference in your effort.

Indeed, but it won't be you on the roof. It has to be a certified installer approved by the SEAI. DIY jobs mean you don't get the grant.

As I also showed in the other thread the panels and labour costs being quoted are not like you suggest above. You need to use real world numbers not direct labour DIY figures.

unkel wrote: »

So €1450 plus VAT. But you get €1400 subsidy for this. But you have to get the battery, so get the cheapest 2.4kWh one for €950. If you accept that you will eventually go battery, you will have to pay for the hybrid converter at some point.

If you decide you are going battery anyway you are ruling out FiT for the lifetime of the system. Thats a personal decision but a bad one imo.

And I think your €950 for the battery is a DIY ex vat price again? It certainly isn't matching up with the certified installer quotes I have.

And where is the battery install labour cost in your figures? I've been quoted €300 for that.

unkel wrote: »

So the cost of that isn't relevant in the calculations (and even if they do come down in value, it is probably easier to install a hybrid one now rather than a conventional one now only to have to change in a few years, get the sparks back in, try to sell your out of date conventional inverter that's almost worthless, etc). So going the extra 2kwp costs about €400 incl VAT and going the battery costs about €500 incl VAT.

Can you show your calculations for the €500? At least your are not saying its free anymore but its still not accurate imo based on the quotes I have.

One installer has told me they do buy back inverters but I agree they are likely to give you pittance for it anyway as it would have only been a few hundred new so I get that point. If you are hell bent on getting batteries at some point in the future then yes, I agree with you, you should do 4kWp now and the cheapest battery you can. However, you need to be doing it for non-financial reasons (environment, off-grid, power outage backup, etc) at the moment as the quotes I have don't have a reasonable payback for batteries.


I need to ask more questions about hybrid inverter compatibility though as it has been mentioned as an issue. Hybrid inverters are still considered new tech. They are around a good few years but its still relatively new. Think of them like EV's... around nearly 10yrs but still evolving fast.

unkel wrote: »

Look, no matter what way you rig the sums, you'd be insane to install a 2kwp system under this subsidy regime. Either do a cheaper install using your own installer or DIY and your own parts (nothing to do with SEAI), but if you are going the subsidy route, the optimal choice is 4kwp plus tiny battery

A 2kWp peak system could also work if you can self consume a high percentage of it. I've looked at my consumption and it can work with reasonable payback but you need high daytime consumption(which I have). It won't work for a lot of people (e.g. Two people out working all day).

The 4kWp with tiny battery I'd agree with, if the price of the battery/inverter dropped in price.... maybe another €700 or so.

Buying now means the grant is just subsidising an expensive battery and still leaving you with a very long payback. If the battery came down in price it would just about make sense with the grant covering the cost of the hybrid inverter.



Are you going to put in a battery yourself? I look forward to hearing about your battery install, costs and savings!

NickSantigo

Guys,
Has anyone put in Solar PV with Electric Ireland
They are doing the following:
1.8 kilowatt installation with diverter for hot water which costs €4490.00 will be eligible for a grant of €1260.00, The Net Cost to homeowner will be €3230.0

You can then do use the HRI to get a further 13.5% off the 3230

I have recently moved into a 1970s bungalow that is 1500sq feet. The is ofch which also needs to be upgraded. I am thinking of going for the above offer and would be interested to hear from anyone who has gone with Electric Ireland

denismc

NickSantigo wrote: »

Guys,
Has anyone put in Solar PV with Electric Ireland
They are doing the following:
1.8 kilowatt installation with diverter for hot water which costs €4490.00 will be eligible for a grant of €1260.00, The Net Cost to homeowner will be €3230.0

You can then do use the HRI to get a further 13.5% off the 3230

I have recently moved into a 1970s bungalow that is 1500sq feet. The is ofch which also needs to be upgraded. I am thinking of going for the above offer and would be interested to hear from anyone who has gone with Electric Ireland

Thats not to bad,
I got 2.08kw installed in April (before the grant) for around 3200 from a private company.

The only thing I would say is, with 1.8 kw you won't have a huge surplus for your diverter especially in Winter, is there an option to get the installation without the diverter?

NickSantigo

I had a read of this paper:
https://www.ucd.ie/t4cms/UCD_Financial%20Performance%20of%20Residential%20PV_with%20figs_revised.pdf

Looking at it I have accepted I won't get a lot from it in Nov, Dec and Jan but I'm hoping the shoulder months and the summer it will help with my hot water demands. In the winter the OFCH will be heating the water anyway so I should have hot water all year round between the two

Water John

Your best value for money in the 1970s house is insulation and air tightness. If you can save a tank of oil per year, that's €700.
If finance isn't a limiting factor, do everything you can under the HRI and get the vat back. I think that closes the end of the year.

NickSantigo

Water John wrote: »

Your best value for money in the 1970s house is insulation and air tightness. If you can save a tank of oil per year, that's €700.
If finance isn't a limiting factor, do everything you can under the HRI and get the vat back. I think that closes the end of the year.

I have to agree. The plan is as follows:
Upgrade attic insulation (walls have already been pumped)
Upgrade Oil Boiler, hot water cylinder and add Rad Controls
Install Solar PV
Install MHRV as there are no vents in any of the rooms

There are already double glazed windows, a conservatory, two stoves and a porch so not sure what else I can do to achieve a better air tightness tbh

gunnerfitzy

NickSantigo wrote: »

Guys,
Has anyone put in Solar PV with Electric Ireland
They are doing the following:
1.8 kilowatt installation with diverter for hot water which costs €4490.00 will be eligible for a grant of €1260.00, The Net Cost to homeowner will be €3230.0

You can then do use the HRI to get a further 13.5% off the 3230

I have recently moved into a 1970s bungalow that is 1500sq feet. The is ofch which also needs to be upgraded. I am thinking of going for the above offer and would be interested to hear from anyone who has gone with Electric Ireland

In relation to the HRI, note that if you receive a grant for qualifying work then the total qualifying expenditure will be reduced by three times the grant amount.

In all likelihood, you will not be eligible for HRI if you avail of the Solar PV grant.

https://www.revenue.ie/en/property/home-renovation-incentive/hri-for-homeowners-and-landlords/value-of-the-hri-tax-credit.aspx

rolion

NickSantigo wrote: »

I had a read of this paper:
https://www.ucd.ie/t4cms/UCD_Financial%20Performance%20of%20Residential%20PV_with%20figs_revised.pdf

Looking at it I have accepted I won't get a lot from it in Nov, Dec and Jan but I'm hoping the shoulder months and the summer it will help with my hot water demands. In the winter the OFCH will be heating the water anyway so I should have hot water all year round between the two

Subject to your location and PV setup...winter could be a nice keeper warmer for the inverter.

My DIY 5Kw installed power report for past 12 months:
August: 468
September: 385
Octomber: 215
November: 151
December: 77
January: 108
February: 231
March: 282

KCross

@rolion, for reference, what kWp is that graph for?

unkel

KCross wrote: »

Indeed, but it won't be you on the roof. It has to be a certified installer approved by the SEAI. DIY jobs mean you don't get the grant.

As I also showed in the other thread the panels and labour costs being quoted are not like you suggest above. You need to use real world numbers not direct labour DIY figures.

I used panel prices available to the public, in a detailed quote from an installer I would comment if they (who can get trade discount) would charge me more than public prices

And I did include labour - that was the 300 I mentioned for the additional 7 panels. Less than 2 man hours work at 50 per hour plus 200 in additional materials

KCross wrote: »

And I think your €950 for the battery is a DIY ex vat price again? It certainly isn't matching up with the certified installer quotes I have.

And where is the battery install labour cost in your figures? I've been quoted €300 for that.

Can you show your calculations for the €500?

950 again is price available to the public plus 300 install charge = 1250 + 23% VAT -/- 1000 subsidy is roughly 500. And remember you only get the extremely generous extra 1400 on top of this 1000 when you install the battery in a 4kwp system

KCross wrote: »

Are you going to put in a battery yourself? I look forward to hearing about your battery install, costs and savings!

If I had no solar PV at all and I had space for 14 panels and I got PP for it, then yes I would go 14 panels + cheapest battery. Best bang for your buck as I have already demonstrated

But unfortunately I don't have the space on my roof as I already have my attic converted, so 3 large velux windows and I have solar thermal and I already have PV. I have space for maximum 5 panels left, which from a subsidy point of view would make no sense to do anything under the SEAI scheme

KCross

unkel wrote: »

I used panel prices available to the public, in a detailed quote from an installer I would comment if they (who can get trade discount) would charge me more than public prices

And I did include labour - that was the 300 I mentioned for the additional 7 panels. Less than 2 man hours work at 50 per hour plus 200 in additional materials

950 again is price available to the public plus 300 install charge = 1250 + 23% VAT -/- 1000 subsidy is roughly 500. And remember you only get the extremely generous extra 1400 on top of this 1000 when you install the battery in a 4kwp system

The public prices don't count. Its the prices from SEAI registered installers that count.

Is "your guy" an SEAI registered installer?

The PylonTech 2.4kWh battery I've seen in more than one quote was €1200+Vat plus €300+Vat install cost. And then the hybrid inverter on top of that.

unkel wrote: »

If I had no solar PV at all and I had space for 14 panels and I got PP for it, then yes I would go 14 panels + cheapest battery. Best bang for your buck as I have already demonstrated

We'll have to agree to disagree. I don't think you've demonstrated it at all, at least not to me!

unkel wrote: »

But unfortunately I don't have the space on my roof as I already have my attic converted, so 3 large velux windows and I have solar thermal and I already have PV. I have space for maximum 5 panels left, which from a subsidy point of view would make no sense to do anything under the SEAI scheme

Sit tight and wait for FiT and then add the 5 extra panels yourself for less than the cost of a battery and save yourself the batteries and hybrid inverter costs. You'll agree with me yet in time!

listermint

What makes you think people can't self install. There's people in this thread that have done it.

Just because you don't have the skills doesn't mean others don't.

I wouldn't come across as so smug as that's the way it's appearing.

Of course it would work out cheaper for a self install and self purchase. You just need to be skilled.

KCross

Who is that directed at @listermint?
Im all for self-install. Don't think I said otherwise.

unkel

KCross wrote: »

Sit tight and wait for FiT and then add the 5 extra panels yourself for less than the cost of a battery and save yourself the batteries and hybrid inverter costs. You'll agree with me yet in time!

We agree already on me not getting a battery in the next few years (FIT or not) and there is no chance I'd go up on the roof of my house unless it was an emergency

Several people including yourself have had quotes of around €7k incl VAT after the grant for a 4kwp with 4.8kWh battery. Surely any installer doing that would do €6k for 4kwp with 2.4kWh battery as that would give them the same profit. If I hadn't anything yet, that's what I would go for

The €3,800 subsidy on that system is just insanely generous. Buying the parts and installing it yourself would cost more even with inflated parts prices and rip off install costs the ESAI approved installers charge you.

niallers1

You might be able to D.I.Y. cheaper but I'd pay the extra to get a professional to do it and take the risk of working at height.

The grant takes alot of the cost away for people ( majority) who will never attempt the install themselves.
Without grant I would not get solar
With grant I will.

serox_21

Sometimes this companies called "professionals" might not do the best job. They are looking to maximize profit, use cheaper components, installation done to pass minimum required standards. Time is money so they will look to finish as soon as possible.

As a DIY you will want to have it done the best way possible(better cable management, extra protections, better equipment, thicker cables).

Shefwedfan

niallers1 wrote: »

You might be able to D.I.Y. cheaper but I'd pay the extra to get a professional to do it and take the risk of working at height.

The grant takes alot of the cost away for people ( majority) who will never attempt the install themselves.
Without grant I would not get solar
With grant I will.

I live in a bungalow :-) could hurt myself more changing a light bulb :P:P:P:P