How many solar panels?

masterboy123

In the process of getting a new home.

Builder said there will be 4 Solar panels to achieve A3 energy rating. However, I have seen 7 or more solar panels of same size in other new builts, which has similar living area of 120 m2.

Any thoughts why it may different from one home to another? And if 4 are enough?

Gumbo

masterboy123 wrote: »

In the process of getting a new home.

Builder said there will be 4 Solar panels to achieve A3 energy rating. However, I have seen 7 or more solar panels of same size in other new builts, which has similar living area of 120 m2.

Any thoughts why it may different from one home to another? And if 4 are enough?

4 solar panels is a compliance installation. It meets the requirements under Part L of the building regulations.

The houses with more, is most likely because the owners wanted more panels and paid for the bigger system.

masterboy123

Ah i see. Thanks for shedding light here.

Do you recommend getting more solar panels? If its going to make a big difference? And also is 60 Litre boiler good enough connected to this solar PV system?

kceire wrote: »

4 solar panels is a compliance installation. It meets the requirements under Part L of the building regulations.

The houses with more, is most likely because the owners wanted more panels and paid for the bigger system.

Gumbo

masterboy123 wrote: »

Ah i see. Thanks for shedding light here.

Do you recommend getting more solar panels? If its going to make a big difference? And also is 60 Litre boiler good enough connected to this solar PV system?

Are they solar thermal or solar PV?

Not sure what the 60L reference is to the boiler?

masterboy123

It's solar PV.

Builder said there is water tank of 60 L which will have hot water available 24 hours. Not sure if it's connected to Solar PV system?

kceire wrote: »

Are they solar thermal or solar PV?

Not sure what the 60L reference is to the boiler?

lazeedaisy

We initially had 4, but when it went to planning we were told it had to be 5 for the number of people anticipated living in it, so we had to change the plans

Gumbo

masterboy123 wrote: »

It's solar PV.

Builder said there is water tank of 60 L which will have hot water available 24 hours. Not sure if it's connected to Solar PV system?

Sounds weird? Most hot water tanks would be 200L minimum. Most new builds in involved in would be 300L cylinders.

Gumbo

lazeedaisy wrote: »

We initially had 4, but when it went to planning we were told it had to be 5 for the number of people anticipated living in it, so we had to change the plans

Planning has nothing to do with it.
It’s the calculations for the renewable element to comply with the building regulations. 4 panels or 5 panels would be exempt from planning.

Shefwedfan

masterboy123 wrote: »

It's solar PV.

Builder said there is water tank of 60 L which will have hot water available 24 hours. Not sure if it's connected to Solar PV system?

Is it housing estate or your own build? How big is house?

masterboy123

It's a housing estate.

113 m2 with 3 bedrooms and 1 walk in wardrobe.

Am I missing something?

Shefwedfan wrote: »

Is it housing estate or your own build? How big is house?

masterboy123

Hmm... It looks like I am missing something here.
I was told this 60 L tank will provide continuous hot water for free as its connected to Solar PV.

kceire wrote: »

Sounds weird? Most hot water tanks would be 200L minimum. Most new builds in involved in would be 300L cylinders.

sydthebeat

masterboy123 wrote: »

Hmm... It looks like I am missing something here.
I was told this 60 L tank will provide continuous hot water for free as its connected to Solar PV.

60 litres is quite a small size for a 3 bed house. One small bath and it would be empty.

The panels probably could keep a cylinder that size heated as it's so small.... Though id question whether a cylinder of that size is suitable for a small family

masterboy123

So I have looked into the specifications now. Please have a look below:

Cylinder: 30 GAL Copper Cylinder Factory insulated

Storage Tank: 40 GAL Plastic Tank

Expansion Tank: 10 GAL Plastic Tank

Gas Boiler: 60,000 BTU Output

Heating Pump: 1 No. WILO.

Photovoltaic Solar Panel : Yes.


Does this make sense? Apologies I am not familiar with these numbers.

sydthebeat

30 gallons is approx 115 litres

Much better

Gumbo

115L still very small in my opinion.
I have seen a tank smaller than 300L in a new build in recent years.

masterboy123

Does storage tank counts?

kceire wrote: »

115L still very small in my opinion.
I have seen a tank smaller than 300L in a new build in recent years.

sydthebeat

masterboy123 wrote: »

Does storage tank counts?

No, that tank is just storing cold water that would be used to flush toilets and for cold taps in bathrooms.

Gumbo

masterboy123 wrote: »

Does storage tank counts?

No. That’s your cold water storage in the attic space.
What development are you buying in?

0lddog

*** Off Topic remark not really helpful to the thread ***

Dont you just love how capacity specs are given in Gallons and BTUs

When was the metric change over ? mid 70's ?

masterboy123

Alright

Thanks everyone.

I will talk to the builder about the boiler capacity.

Gumbo

masterboy123 wrote: »

Alright

Thanks everyone.

I will talk to the builder about the boiler capacity.

This makes no sense.
First you must work out what you are going to ask him.

The boiler doesn't have a capacity.

masterboy123

Thanks for the correction.

*I will ask about that cylinders capacity.

kceire wrote: »

This makes no sense.
First you must work out what you are going to ask him.

The boiler doesn't have a capacity.

Shefwedfan

masterboy123 wrote: »

It's a housing estate.

113 m2 with 3 bedrooms and 1 walk in wardrobe.

Am I missing something?

If housing estate and new build they probably have a website with spec's of what you are getting? might be quicker to point in that direction


As already pointed out the 60l would have been too small...


I would expect 4 solar panels will not generate enough either to heat any water, even in the height of summer

masterboy123

They don't have a website. Ad used to be on the daft but once all the properties were sold, they took that down also.

So if 4 Solar panels are not enough, how many would suffice?

Shefwedfan wrote: »

If housing estate and new build they probably have a website with spec's of what you are getting? might be quicker to point in that direction


As already pointed out the 60l would have been too small...


I would expect 4 solar panels will not generate enough either to heat any water, even in the height of summer

Shefwedfan

masterboy123 wrote: »

They don't have a website. Ad used to be on the daft but once all the properties were sold, they took that down also.

So if 4 Solar panels are not enough, how many would suffice?

Solar PV is not really great for water. I guess they are saying when you are out during the day it will not use the electricity so they will divert to the water and heat it?


What output are the panels? 250w or more?


You are probably limited with the amount of space on the roof with the amount of panels. Lets say you do have 2 x 250w. In my house I have a constant 200w to keep s**t going even when not in house. Its the baseline so to speak. So with the solar PV that will be gone from electricity bills so it will reduce costs.

I think it is great and I would love even that but I would not be expecting to come home at night and have a tank full of hot water. Some of the more technical people on here might know more....


If they brought in FiT in might be better if you have the option to pump it back into the grid if ESB are paying you for it. Might just be worth considering but then the problem is when will they give out FiT(feed in tariff)

Gumbo

Shefwedfan wrote: »

If housing estate and new build they probably have a website with spec's of what you are getting? might be quicker to point in that direction


As already pointed out the 60l would have been too small...


I would expect 4 solar panels will not generate enough either to heat any water, even in the height of summer

4 panels is most likely a 1.2kw system. Anything less wont pass Part L.
If the OP fitted a divertor then on sunny days there would be ample amount to trickle heat the immersion but, no divertor will be fitted by the developers as it’s not a requirement.

Shefwedfan

kceire wrote: »

4 panels is most likely a 1.2kw system. Anything less wont pass Part L.
If the OP fitted a divertor then on sunny days there would be ample amount to trickle heat the immersion but, no divertor will be fitted by the developers as it’s not a requirement.

Would it? Even with base load?

jonnyha

Or it's 136 litres if it's 30 UK gallons, rather than US gallons.

Gumbo

Shefwedfan wrote: »

Would it? Even with base load?

Yes. The base load of a house is nowhere near 1kw.

Gumbo

jonnyha wrote: »

Or it's 136 litres if it's 30 UK gallons, rather than US gallons.

Still the smallest cyclinder ive Seen installed in a new dwelling in over 15 years. Something. It right with the OP’s info.

ethernet

kceire wrote: »

Yes. The base load of a house is nowhere near 1kw.

Mine is!

Gumbo

ethernet wrote: »

Mine is!

The average 3 bed semi doesn’t need 1kw as a base load.
Maybe you are mining crypto

To clarify, the base load is the house when nobody is home. So effectively when the house is empty, there can’t be much on standby that needs more than that. Fridge, freezer, even if every tv is on red light standby.

My own house is well below, in fact, on days where my PV is only generating 1kw if will still be sending a couple of hundred w or the immersion through the divertor.

I also have a 7 camera IP cctv system running constantly that would add to my baseload.