Solar Pv New Build

bananalad

Starting a new build March/April 2022 and have some questions regarding solar pv.

I have been researching solar for the last number of months and I’ve decided to place my panels on my garage that has an east/west roof.

I have decided that I won’t be going down the battery route.

Now I see the general consensus is to place as many panels possible on your roof. I have made up that I could potentially fit 32 Longi 360w panels.

Hopefully if it works out price wise I’ll be looking to get a 3 phase 29Kva connection to allow for fast charging an EV in the future.

I will be fitting the panels on the roof myself and getting a friend who is a qualified electrician to wire them/sign off on it.

Now my question, Is it madness going for the full 32 panel 11.52kw with a 10kw 3 phase solis inverter? Looking at the kits online it looks to be working out around €7k plus the vat.

Or option 2 is a 21 panel 7.36kw system with a 6kw solis inverter working out around €4.5k plus the vat.

Thanks for reading and any questions, ask away!

Deagol

I'm assuming you have a business premises or something to have a 3 phase connection?

bananalad

https://www.boards.ie/discussion/comment/118281105#Comment_118281105

A domestic premises can apply for a 3 phase connection, the power runs past where I plan to build. It’s not that much more to get the 29kVA compared to 16kVA. I know there’s a higher standing charge but not sure of any other disadvantages?

Jonathan

Are you going with a heat pump for your new build? If you are, having three phase would be an advantage.

bananalad

https://www.boards.ie/discussion/comment/118284203#Comment_118284203

Yes I was planning on going with a Samsung air to water unit. What advantage is three phase with a heat pump?

Jonathan

https://www.boards.ie/discussion/comment/118284480#Comment_118284480

Three phase will allow you to get a larger heat pump, and it will also run quieter (less vibrations) compared to a single phase equivalent. A single phase system will also suffer from large inrush currents, which three phase system does not.

bananalad

Would you happen to know of any disadvantages to 3 phase other than the higher standing charge and the initial cost of getting it in?

ECO_Mental

Just had the same conversation about a year ago in the EV threads and I have just moved into my house just over a month ago. The general consensus in the EV thread was that yeah it would be nice but in reality having a 3 phase power supply to charge your car for your home but is a bit over kill and only useful if you are planning to do a lot of mileage in your EV. If you think about it you are going to charge your car over night to be ready for work in the morning 7kW over night will do this, a 22kW charger will only do this faster but either way your car will be charged in the morning.

Dont know where you are building but 3 phase lines aren't all that common but you could be lucky and have one running at the end of your drive and it might be no harm to ask and it might not cost you all that much. For me there was no 3 phase any where near me so that answered that question for me so I got a 16 kVA connection

Regarding Solar PV I have 6.1kWp and its only on again for only 2 months and I am still learning to use the most out of it and I need to get better monitoring of how much I am actually using and putting back into the grid. From reading posts here though I saw around 6 kWp is about right for the vast majority of home owners.

bananalad

The whole 3 phase thing never crossed my mind untill I realised the 3 phase wires are running through my soon to be back garden about 20 meters from the house.

I will enquire how much extra it will be to get hooked up to it in the new year and it will make my decision easier with how many pv panels to go with!

THE ALM

I think long term 3 phase would be the way to go if readily accessible and not silly money to install, it certainly future proofs the house as more and more things will go electric/battery storage.

Fake Bono

Hi Can anyone help

Is 8k a fair price for a 5.3 kw system with an Eddi and 5k Solis 4g inverter. 12 440kw panels?

THE ALM

https://www.boards.ie/discussion/comment/118546661#Comment_118546661

Is this before or after the grant? If after grant it is too high.

Check this thread to see quotes to give you an idea about prices and post up you query with a few details of what type of install you are doing, type of roof, orientation etc.

MAULBROOK

https://www.boards.ie/discussion/comment/118546661#Comment_118546661

Over the odds, no battery?

MAULBROOK

https://www.boards.ie/discussion/comment/118286567#Comment_118286567

Go big on the panels is always my advice. Better to be looking at them than looking for them.

Is it a DIY install.