Solar PV - is it worth it?

unkel

niallers1 wrote: »

You might be able to D.I.Y. cheaper

Not on the 4kwp + battery system. The parts alone would cost you more than a SEAI installer would charge you for doing the complete job.

About the best prices you can get are

panels 14 * 148, inverter 1200, batteries 1900, mounting and other 600 (this is extremely tight), total 5770 + VAT which will bring it well over the 7k mark SEAI approved installers have quoted

On a smaller system it could be worth your while DIY. Even if you don't want to go on your roof, a recommended roofer could install the panels for you for fairly little money. If you do the cabling yourself, I can't see a sparks charging more than 200 for hooking it all up

wexfordman2

unkel wrote: »

Not on the 4kwp + battery system. The parts alone would cost you more than a SEAI installer would charge you for doing the complete job.

About the best prices you can get are

panels 14 * 148, inverter 1200, batteries 1900, mounting and other 600 (this is extremely tight), total 5770 + VAT which will bring it well over the 7k mark SEAI approved installers have quoted

On a smaller system it could be worth your while DIY. Even if you don't want to go on your roof, a recommended roofer could install the panels for you for fairly little money. If you do the cabling yourself, I can't see a sparks charging more than 200 for hooking it all up

The 7k you mention for the 4kw plus battery, is that before or after the grant, cos every price I am getting so far is in or about 11k (Inc vat), so just over 7k after the grant.

Are you saying 7k before the grant ?

unkel

No after the grant. So 7k cost to the homeowner, everything included (incl VAT). And as I demonstrated the parts alone incl VAT would cost more

uck51js9zml2yt

Guys whats the thinking on evacuated tubes against flat panels?

Been reading about them and there's no definitive answer!

unkel

Ayleen Polite Mockingbird wrote: »

Guys whats the thinking on evacuated tubes against flat panels?

This thread is about solar PV

For solar hot water heating, panels are better looking, but more expensive and less efficient. So have a far longer payback. And don't do either, unless you use a lot of hot water (a lot more than the national average)

robp

unkel wrote: »

This thread is about solar PV

For solar hot water heating, panels are better looking, but more expensive and less efficient. So have a far longer payback. And don't do either, unless you use a lot of hot water (a lot more than the national average)

Do payback figures take into account that unused hot water provides background house heating? I think a lot of payback figures are very optimistic. Consumers and the renewable industry don't seem to take into account human behaviour at all. For example if you make hot water free, more hot water is used.

unkel

We use more hot water now because it's free. And because it is heated by the sun. Exactly as you say. If my teenage daughter now has a 30 minute shower, I don't give out. I would have given out if I had to pay for her excessive use of my boiler burning fossil fuel.

My payback calculations were based on our consumption and behaviour prior to having the system installed though.

eire1987

rolion wrote: »

I'll go with the best insulation available on the market today.
Insulate with a 100-200 mm and make it sound proof / water tight / airtight up to being a "passive maniac".

Once you have a closed container / framework,get a heat recovery ventilation.

Then,heating it and retaing that heat it will be your last problem...the smaller heat pump or boiler or radiator/underfloor heating systems combination with a nice multizoned automated controls ... will have to work very small / low energy transformation to get a temperature boost from a nice constant 15ish to 20ish.

Next,subject to budget,i will go with few solar tubes for hot water and PVs for electricity.IF budget tight,go for PVs and diverter.

Any decision,enjoy the adventure of self build...i envy you !

We decided to go with the hone system, I have to say I was very vary of what their system has however I have to say we were impressed so we are going with a timber framed house with the hone system... I will keep the group posted in how things worked out with hone if ye want..

Meeting the planner on Tuesday he was quite positive towards us going for this... So hopefully it will be good!!

unkel

Looks like you fell for their sharp sales tactics. But don't take my word for it. Do yourself a favour and pay an independent consultant go over the "hone system" plans before you commit your money.

unkel

The inventor behind the Hone system is soon to become a billionaire

Linky

eire1987

unkel wrote: »

Looks like you fell for their sharp sales tactics. But don't take my word for it. Do yourself a favour and pay an independent consultant go over the "hone system" plans before you commit your money.

Ok, so you have used their service before?

bleary

unkel wrote: »

The inventor behind the Hone system is soon to become a billionaire

Linky

Published over 2 years ago. Wonder if those other companies have caught up yet. "I have it on good authority that some other companies have spent €250m trying to get to where we are, but they're nowhere near"
No sign of the factories designed specifically to create more jobs

"He emphasises plans to set up factories wherever its technology is rolled out, each employing about 700 people, with a manufacturing process intentionally designed not to rely on robots or automation, in order to create the maximum number of jobs."
Anyway off topic

wexfordman2

bleary wrote: »

Published over 2 years ago. Wonder if those other companies have caught up yet. "I have it on good authority that some other companies have spent €250m trying to get to where we are, but they're nowhere near"
No sign of the factories designed specifically to create more jobs

"He emphasises plans to set up factories wherever its technology is rolled out, each employing about 700 people, with a manufacturing process intentionally designed not to rely on robots or automation, in order to create the maximum number of jobs."
Anyway off topic

I sometimes wonder his any reputable "journalist" and "newspaper" can publish articles like that without even basic challenges like that.

Does anyone know where any of these factories employing 700 people are ?

denismc

eire1987 wrote: »

Ok, so you have used their service before?

If you do go ahead with this system could maybe report back here and let us know how you find it.

eire1987

denismc wrote: »

If you do go ahead with this system could maybe report back here and let us know how you find it.

Yeah no problems. Like tbf I don't dispute much of debate surrounding them in terms are talking BS or not because I can't speak about solar panels... However I must say that I have got an outside opinion about them (the guy i was talking to would know a bit about solar panels) he did say that some of that RTE report was a bit bogus in terms of the house they used, does the system acutally work etc... But he did make a point to me that im doing a new build rather than doing a retrofit.. also the company were using for the timber frame have their own system.. so it is a different situation...

However once the quote is in and we finish our plan with the company thats building it I will report here when we start at it

ActingDanClark

Currently in the process of getting quotes. South facing roof which will take max 7 panels, allowing 2240 KW. Price including Eddi and nett of grant approximately €3100. I'm not hugely hung up on ROI, won't be borrowing $$ but just seeking opinions whether it's worth doing?
(Always someone at home daytime, consume 4195 units pa, electric shower which I'd happily replace)

unkel

I wouldn't buy an Eddi with a small setup like that. It's cheaper (and greener) to give your excess production back to the grid for free.

ActingDanClark

unkel wrote: »

I wouldn't buy an Eddi with a small setup like that. It's cheaper (and greener) to give your excess production back to the grid for free.

Neglected to mention house is located north east Wicklow. Would you envisage this system making much of a dent in my electricity bills? All led bulbs, all appliances at least A+

unkel

There's always someone in your house during the day, so they can switch on the dishwasher, washing machine, dryer, do the hoovering, cut the grass with an electric mower, etc. when it is bright / sunny. One of the above at a time. And yes it will make a significant dent in your electricity bills if you adjust your behaviour towards making the most of your solar PV

Payback times are exaggerated by almost everybody almost all of the time though. Your case is good, you get the subsidy, if you get a decent price for your install you are probably talking about 10-15 years or thereabouts. But of course it is not just about money

uck51js9zml2yt

ActingDanClark wrote: »

Currently in the process of getting quotes. South facing roof which will take max 7 panels, allowing 2240 KW. Price including Eddi and nett of grant approximately €3100. I'm not hugely hung up on ROI, won't be borrowing $$ but just seeking opinions whether it's worth doing?
(Always someone at home daytime, consume 4195 units pa, electric shower which I'd happily replace)

Why not get a battery for the evening ?

ActingDanClark

Ayleen Polite Mockingbird wrote: »

Why not get a battery for the evening ?

Installer says it's not worth my while?

ActingDanClark

unkel wrote: »

There's always someone in your house during the day, so they can switch on the dishwasher, washing machine, dryer, do the hoovering, cut the grass with an electric mower, etc. when it is bright / sunny. One of the above at a time. And yes it will make a significant dent in your electricity bills if you adjust your behaviour towards making the most of your solar PV

Payback times are exaggerated by almost everybody almost all of the time though. Your case is good, you get the subsidy, if you get a decent price for your install you are probably talking about 10-15 years or thereabouts. But of course it is not just about money

Average electricity bill is e160 so it'd be nice to see that reduced.

wexfordman2

ActingDanClark wrote: »

Average electricity bill is e160 so it'd be nice to see that reduced.

Is that per month or bi monthly ?

denismc

ActingDanClark wrote: »

Currently in the process of getting quotes. South facing roof which will take max 7 panels, allowing 2240 KW. Price including Eddi and nett of grant approximately €3100. I'm not hugely hung up on ROI, won't be borrowing $$ but just seeking opinions whether it's worth doing?
(Always someone at home daytime, consume 4195 units pa, electric shower which I'd happily replace)

Thats a decent price, I paid similar for a similar sized system before the grant. That EDDI unit unit alone costs over £500 sterling before installation, so its not going to pay for itself anytime soon but it is a nice to have.

If you have someone at home during the day cooking, washing, cleaning then you will definitely see a reduction in your bills.
My system is 2.1kw and I reckon I use between 1/3 and 1/2 of what I produce.

uck51js9zml2yt

Just reading about the Eddi. Looks a interesting idea.

Can I ask a question? The solar panels generate electricity for use. Then divert to the immersion heater until it reaches max.
Is it possible to then divert the balance to a battery rather than back to the grid for nighttime use?

ActingDanClark

wexfordman2 wrote: »

Is that per month or bi monthly ?

Bimonthly

unkel

Ayleen Polite Mockingbird wrote: »

Can I ask a question? The solar panels generate electricity for use. Then divert to the immersion heater until it reaches max.
Is it possible to then divert the balance to a battery rather than back to the grid for nighttime use?

Yes that's all possible, but with a small PV array (say less than 3-4kwp), it is cheaper to give away your electricity for free to the grid than to use a diverter (Eddi) and much cheaper than using a battery

funnyname

unkel wrote: »

Yes that's all possible, but with a small PV array (say less than 3-4kwp), it is cheaper to give away your electricity for free to the grid than to use a diverter (Eddi) and much cheaper than using a battery

Can you explain the maths of that?

KCross

funnyname wrote: »

Can you explain the maths of that?

The Eddi is €400. Maybe add another €100 to fit.

A 2.4kWh battery plus hybrid inverter costs about €2k and €300 for labour. A net €1300+ to you after grant.

So, net cost to you for both diverter systems will be about €1800+


€1800 of night rate electricity would equate to 22,000 units of electricity. You will "never" see your money back for either of those systems to save you 22000 units of electricity... hence "cheaper" to just give the excess away to the grid and save yourself the €1800 for something else.

unkel

And before anyone else butts in - yes you can use the battery in the evening time for your peak electric consumption (before night rate kicks in) and yes in some battery systems you can load them up with night rate and use the cheap night rate for your expensive day rate consumption

But with currently still very high battery prices and limited battery lifespan, basically the cost of using 1kWh of battery cycling itself costs almost as much as 1kWh of buying electricity from the grid at peak rates. So even if you could fill up the battery partly for free with the sun and partly for cheap with cheap night rate, it still doesn't make economic sense

One consideration is if you plan to go battery in a few years time (when the price has come down significantly). You might want to consider having all the hardware (hybrid inverter, small battery) in place now to cater for installing additional big cheap batteries later. Particularly because you can now do so with a very generous subsidy

Doing clear sums is nearly impossible here as we can't look into the future. We don't know how long this subsidy will last, we don't know what the future price of batteries and other hardware is, we don't know the future price of electricity and we don't know if we will at some point get a (lucrative) feed in tariff (get paid for the electricity we produce that we are not using ourselves)