Solar PV - is it worth it?

wexfordman2

Oky, been thinking about solar pv for a long time, this might just push me towards getting it. If its ok, can I ask a few general questions


1) My house, average bill is 130pm through level pay.
2) I have south facing house with plenty of roof space.


So, first off, is a 4kw system a good size for me, or should I go higher, and anyone have a rough idea of pricing for a 4kw with battery, and maybe a bigger system also (6kw) with battery

Thanks,

Shefwedfan

wexfordman2 wrote: »

Oky, been thinking about solar pv for a long time, this might just push me towards getting it. If its ok, can I ask a few general questions


1) My house, average bill is 130pm through level pay.
2) I have south facing house with plenty of roof space.


So, first off, is a 4kw system a good size for me, or should I go higher, and anyone have a rough idea of pricing for a 4kw with battery, and maybe a bigger system also (6kw) with battery

Thanks,

You are the same price as me per month. Do you have day/night meter?


I got a couple of sizes done and everything from 4kW to 6kW has been recommended. It is not small money. Especially as once you go over 2kW you need to buy battery



I think I might pull trigger on 2kW system. This is based on energy monitor and most days the house is ticking over at 2kW. So if I can heat water and keep house going that would be job. I will do analysis this evening from monitor.


Then plan would be to buy anohter 2kW or more with battery next year. I have question in SEAI if I can do it that way and get grant.

wexfordman2

Shefwedfan wrote: »

You are the same price as me per month. Do you have day/night meter?


I got a couple of sizes done and everything from 4kW to 6kW has been recommended. It is not small money. Especially as once you go over 2kW you need to buy battery




I think I might pull trigger on 2kW system. This is based on energy monitor and most days the house is ticking over at 2kW. So if I can heat water and keep house going that would be job. I will do analysis this evening from monitor.


Then plan would be to buy anohter 2kW or more with battery next year. I have question in SEAI if I can do it that way and get grant.

I have night saver, as well. Did you get any indicitave pricing ofr the 4kw and 6kw with battery ?

Shefwedfan

wexfordman2 wrote: »

I have night saver, as well. Did you get any indicitave pricing ofr the 4kw and 6kw with battery ?

I might have pricing for all options :P


I am running analysis now on my actual requirements. If the bloody Owl would export the data without hanging. I will update once it exports

unkel

Please update us with detailed pricing as well! I like the idea of a battery as well, but I would probably go for a small one at the moment

Gumbo

wexfordman2 wrote: »

Oky, been thinking about solar pv for a long time, this might just push me towards getting it. If its ok, can I ask a few general questions


1) My house, average bill is 130pm through level pay.
2) I have south facing house with plenty of roof space.


So, first off, is a 4kw system a good size for me, or should I go higher, and anyone have a rough idea of pricing for a 4kw with battery, and maybe a bigger system also (6kw) with battery

Thanks,

Your first problem will be fitting a 4 kw system onto your roof.
Using 300w panels, that's 14 panels, so depending on your house, this may or may not fit, and then you have the planning issues to contend with.

unkel

Panels are 99 * 165cm, so if the 12m2 max applies, you can only install 7 panels

WHL

Do you need planning permission to put panels on a South-facing house? If so that would make my decision easy

ted1

gally74 wrote: »

alejandro1977 wrote: »

Not to be dependent on others?

So spend money importing panels from China and deploy them in a sub optimal location to provide some electricity at time of low demand?

I'd rather the ESB plonk a load of them in Spain where land is barren and scale can be achieved. That would give a lot more bang per buck financially and environmentally

Transmission losses 50 %

That’s complete rubbish, losses are nowhere need that especially in a HVDC or even on a MVDC link

Gumbo

WHL wrote: »

Do you need planning permission to put panels on a South-facing house? If so that would make my decision easy

It doesn’t matter what orientation your house is in.the planning exemption is 12 Sq. M or 50% of the roof area, whatever is reached first.

drunkmonkey

Is there a point at which this becomes a no brainer, as in if you've a huge roof forget about the hot water but my electricity is above €250pm how many panels do you need to generate that kind of power.

Gumbo

drunkmonkey wrote: »

Is there a point at which this becomes a no brainer, as in if you've a huge roof forget about the hot water but my electricity is above €250pm how many panels do you need to generate that kind of power.

It’s about using the power generated.
No point generating all the power during the day while your in work, so in my opinion a battery is essential!

Our leccy bill is about 180-190 Pm , I still wouldn't consider PV at this time. I'm not a fan of dumping energy and a battery only adds to the cost.

goat2

kceire wrote: »

It doesn’t matter what orientation your house is in.the planning exemption is 12 Sq. M or 50% of the roof area, whatever is reached first.

I thought the orientation of the house would be of huge importance, especially during the mid winter months, South facing being best way to go

H.E. Pennypacker

I've a quote for a 2.1 kw 7 x 300w panels, inverter and immersion diverter coming to €4,400 including vat.


Adding a 2.5kWh battery to that brings it to €10,800. It must be quite a battery.....

To my mind, a correctly sized and reasonably priced battery would make the immersion diverter unnecessary

10,800 ? that a bit mental, buys a lot of electricity !

Shefwedfan

H.E. Pennypacker wrote: »

I've a quote for a 2.1 kw 7 x 300w panels, inverter and immersion diverter coming to €4,400 including vat.


Adding a 2.5kWh battery to that brings it to €10,800. It must be quite a battery.....

To my mind, a correctly sized and reasonably priced battery would make the immersion diverter unnecessary

The batteries are mental price at the moment.....I can't see a reason to invest...Solar PV yes, Battery no

unkel

H.E. Pennypacker wrote: »

I've a quote for a 2.1 kw 7 x 300w panels, inverter and immersion diverter coming to €4,400 including vat.


Adding a 2.5kWh battery to that brings it to €10,800. It must be quite a battery.....

To my mind, a correctly sized and reasonably priced battery would make the immersion diverter unnecessary

€6,400 for a 2.5kWh battery is an outrageous rip off. A 2.2kWh battery costs €900 + VAT and install costs are not high

See here, check out the post from quentingargan

H.E. Pennypacker

unkel wrote: »

€6,400 for a 2.5kWh battery is an outrageous rip off. A 2.2kWh battery costs €900 + VAT and install costs are not high

See here, check out the post from quentingargan

I hope that its not the first sign of grant price inflation. I had a quote for panels already so the only place to grow the price is the battery

Of course installers are going to cash in on any grant, but there's no grant yet. The Government won't do anything to ensure the consumer benefits and not the installer.

niallers1

I received a quote for 4.13kw solar pv with 4.8kw (2*2.4kw) battery. With Grant comes in at 7k even (Includes VAT)The battery was 2,700 (includes vat)

niallers1

I received a quote for 4.13kw solar pv with 4.8kw (2*2.4kw) battery. With Grant comes in at 7k even (Includes VAT)The battery was 2,700 (includes vat)

Shefwedfan

niallers1 wrote: »

• I received a quote for 4.13kw solar pv with 4.8kw (2*2.4kw) battery. With Grant comes in at 7k even (Includes VAT)The battery was 2,700 (includes vat)

That after grant? Who gave that if you dont mind me asking?

niallers1

Shefwedfan wrote: »

That after grant? Who gave that if you dont mind me asking?

Don't think I can say name on forum

alejandro1977

niallers1 wrote: »

I received a quote for 4.13kw solar pv with 4.8kw (2*2.4kw) battery. With Grant comes in at 7k even (Includes VAT)The battery was 2,700 (includes vat)

is there really such a need for such a large battery; obviously if you want to go off-grid fine  but wouldn't it be useful to focus on smoothing out sunlight/power fluctuations and

Gumbo

alejandro1977 wrote: »

is there really such a need for such a large battery; obviously if you want to go off-grid fine  but wouldn't it be useful to focus on smoothing out sunlight/power fluctuations and

If your working during the day while panels are generating at their max, then it makes sense to store as much as you can for use later that evening.

Shefwedfan

alejandro1977 wrote: »

is there really such a need for such a large battery; obviously if you want to go off-grid fine but wouldn't it be useful to focus on smoothing out sunlight/power fluctuations and

Part of the reason for battery, or what I was told

During the winter you can fill the battery with night rate electricity. So during the day you can use the night rate and save also in regards to that...


I dont know how much a 5kW battery would keep house ticking over but for a few hours maybe

niallers1

I believe the battery needs to be AC to allow you to store night rate electricity. The AC battery is more expensive than the DC battery

Shefwedfan

niallers1 wrote: »

I believe the battery needs to be AC to allow you to store night rate electricity. The AC battery is more expensive than the DC battery

Could be....something I did not ask....as I did not know :P:P

wexfordman2

niallers1 wrote: »

I received a quote for 4.13kw solar pv with 4.8kw (2*2.4kw) battery. With Grant comes in at 7k even (Includes VAT)The battery was 2,700 (includes vat)

Was that inc or exclusive of grant ?

Cos otherwise its looking like 11k if you include the full grant

niallers1

7k is price when grant is included/taken into account .

What was the battery size again ? 2.7 Kwh ? that's practically going to be useless in Summer when it fills up quickly form a 4.13 Kwp array ! Dumping excess isn't viable in my opinion !

niallers1

2 * 2.4 kwh battery or 4.8 in total

Shefwedfan

niallers1 wrote: »

2 * 2.4 kwh battery or 4.8 in total

Everyone is quoting 5kWh. Anything bigger wil have to be a crashed Leaf and grabbing the battery off it

I still think even a 5 Kwh battery is useless with a 4.13 kwp array. Don't get me wrong, it's better to store 5 Kwh than dump it but I feel a 4.13 Kwp system will generate far more than 5 Kwh worth of electricity in the Summer months per day, not every day, of course but I think significant energy will still have to be dumped.

Good sunny Winter weather could also see a lot of energy dumped.

It's ridiculous there's no push to make the ESB take more energy from Micro generation in the way of FIT.

niallers1

You could also divert to hot water tank with a diverter.

We should see F.I.T. In the next couple of years. I believe this is coming down the road from E.U.

Shefwedfan

niallers1 wrote: »

You could also divert to hot water tank with a diverter.

We should see F.I.T. In the next couple of years. I believe this is coming down the road from E.U.

It will never happen under the EU puts a gun to our head....this backward country would prefer to ruin the countryside with turbines and fields of solar PV

unkel

Shefwedfan wrote: »

It will never happen under the EU puts a gun to our head

I hope they will. We need to take our head out of our arse in this dirty diesel, peat and solid fuel country

Massive emissions fines are almost here for us the tax payer to cough up

Gumbo

Deleted User wrote: »

I still think even a 5 Kwh battery is useless with a 4.13 kwp array. Don't get me wrong, it's better to store 5 Kwh than dump it but I feel a 4.13 Kwp system will generate far more than 5 Kwh worth of electricity in the Summer months per day, not every day, of course but I think significant energy will still have to be dumped.

Good sunny Winter weather could also see a lot of energy dumped.

It's ridiculous there's no push to make the ESB take more energy from Micro generation in the way of FIT.

My 3kw system can generate up to 20kwh a day. Obviously we’ve had a sunnier few weeks though. But 10-13 on average is the normal since last September on decent days.

Today was a bad day. Only 4kwh generated.

The problem with saying a 5kwh battery is worthless, is the cost to go bigger and the size of the unit. You have to start thinking about where to put this battery.

What would the average use be from 6pm to 6am for a typical house?
5kwh would put a major dent in what you draw from the grid if you could fill that most days?

Add to this an immersion divertor and if you get hot water and some storage then your laughing but I’d probably prioritize the battery storage as you can use that to turn on the immersion that evening if required.

Today was the second day since April I’ve had to fire the gas boiler up to heat the water

unkel

kceire wrote: »

My 3kw system can generate up to 20kwh a day. Obviously we’ve had a sunnier few weeks though. But 10-13 on average is the normal since last September on decent days.

Today was a bad day. Only 4kwh generated.

Sounds about right. I've only 1650wp but have generated on average about 6kWh per day over the last week (wasn't very sunny most days). Best day of the year would be about 10-12kWh I guess. Today just over 3kWh

If going for the battery subsidy, I think I'll just go 2.4kWh initially as there is someone in the house most of the time during the day

Capt'n Midnight

gally74 wrote: »

Transmission losses 50 %

Siemens are setting up transmisison lines twice that distance in China.

Anyway on an EU wide grid you aren't transferring power from Spain to Ireland. It's power being offset sequentially from region to region.

Either way chucking solar at Spain or Morocco might be used to offset our Koyoto fines.

Gumbo

unkel wrote: »

Sounds about right. I've only 1650wp but have generated on average about 6kWh per day over the last week (wasn't very sunny most days). Best day of the year would be about 10-12kWh I guess. Today just over 3kWh

If going for the battery subsidy, I think I'll just go 2.4kWh initially as there is someone in the house most of the time during the day

I’d probably go with the cheapest option myself too, just to get going with hopefully the option to simply upgrade the battery at a later date.

unkel

Apparently you can. If I were you I'd do the same thing to get the most out of your diverter. And take full advantage of the subsidy. Do you know if your inverter can handle a battery or do you have to upgrade it? Seems like a bit of a waste to have to change the almost brand new inverter for a much more expensive one. I'm hoping the battery can be setup completely separate from the solar system for reasonable money.

Gumbo

unkel wrote: »

Apparently you can. If I were you I'd do the same thing to get the most out of your diverter. And take full advantage of the subsidy. Do you know if your inverter can handle a battery or do you have to upgrade it? Seems like a bit of a waste to have to change the almost brand new inverter for a much more expensive one. I'm hoping the battery can be setup completely separate from the solar system for reasonable money.

I’m hoping it can be still used. The installers have constantly kept me in the loop with their hybrid battery storage, so I assume it can based on that but I better get a definitive answer from them.

kceire

kceire wrote: »

My 3kw system can generate up to 20kwh a day. Obviously we’ve had a sunnier few weeks though. But 10-13 on average is the normal since last September on decent days.

Today was a bad day. Only 4kwh generated.

The problem with saying a 5kwh battery is worthless, is the cost to go bigger and the size of the unit. You have to start thinking about where to put this battery.

What would the average use be from 6pm to 6am for a typical house?
5kwh would put a major dent in what you draw from the grid if you could fill that most days?

Add to this an immersion divertor and if you get hot water and some storage then your laughing but I’d probably prioritize the battery storage as you can use that to turn on the immersion that evening if required.

Today was the second day since April I’ve had to fire the gas boiler up to heat the water

The problem is that it's substantial energy wasted when the battery is full, if as you say you generate up to 20 Kwh on a sunny day that's a huge loss of energy , dumping it to hot water is fine but who has even close to 20 Kwh of storage in their hot water tank ? I'd say 0.

Before I went EV our daily average house consumption was about 6.5 Kwh per day which I'm told was good.

Only sane way to use solar is FIT, send to the grid all the excess , none is wasted and you buy back only what you need.

Obviously we don't have such a system so in my opinion solar PV is not viable at this time.

Our daily average now is about 15 Kwh per day.

So run by me again, how much was the 4.3 Kwp array with battery including install + grant ?

unkel

Deleted User wrote: »

The problem is that it's substantial energy wasted when the battery is full, if as you say you generate up to 20 Kwh on a sunny day that's a huge loss of energy , dumping it to hot water is fine but who has even close to 20 Kwh of storage in their hot water tank ? I'd say 0.

20kWh will probably be only on an extremely sunny day. More typical on a good day is 12kWh. Which is only just above the average national consumption. A 3kwp south facing array in the Dublin area produces about 2900kWh per year. Average consumption is 3500kWh per year (without heating your water)

There won't be much going to waste here once kceire has even a small battery

ted1

niallers1 wrote: »

I received a quote for 4.13kw solar pv with 4.8kw (2*2.4kw) battery. With Grant comes in at 7k even (Includes VAT)The battery was 2,700 (includes vat)

What’s your end goal ?
Save money? Dump 7k off your mortgage?

Save planet ? Invest the 7k in a renewable energy company

unkel

Almost 10k for a 4kwp system plus 4.8kWh battery doesn't seem a good price at all tbh (7k after subsidy). But if you are going to stay in your house for several decades it will pay for itself and after that you will have substantial savings. Li-Ion batteries last a lot longer than people thought they would. And prices are coming down, you can add more later.

Gumbo

Deleted User wrote: »

The problem is that it's substantial energy wasted when the battery is full, if as you say you generate up to 20 Kwh on a sunny day that's a huge loss of energy , dumping it to hot water is fine but who has even close to 20 Kwh of storage in their hot water tank ? I'd say 0.

Before I went EV our daily average house consumption was about 6.5 Kwh per day which I'm told was good.

Only sane way to use solar is FIT, send to the grid all the excess , none is wasted and you buy back only what you need.

Obviously we don't have such a system so in my opinion solar PV is not viable at this time.

Our daily average now is about 15 Kwh per day.

So run by me again, how much was the 4.3 Kwp array with battery including install + grant ?

20kwh would be rare enough.
FIT is the best option, I agree but it ain’t happen so we got to work with what we have.

I actually dont know what my daily use is, can I work it’s out by checking the meter figures?
I would only dump about 3-4kwh to the immersion on a good day Andy that gives me a full tank of hot water (300L new, highly insulated cylinder).

Also not sure on complete costing for a 4.3 system but my 3kw system including the immersion divertor cost me €2900 supplied and fitted while I was renovating my house last year. I didn’t do it for the financial gain, although it simply nice to save a little, I done it for the environment if I’m honest and to do my little bit as corny as it sounds.

wexfordman2

ted1 wrote: »

What’s your end goal ?
Save money? Dump 7k off your mortgage?

Save planet ? Invest the 7k in a renewable energy company

What if his objective is both ?

What if he has no mortgage?

What if his mortgage interest is costing less then the saving he would generate from solar PV ? Is it not a good investment then ?