Solar PV plan for 3 phase supplied house - Is there an idiot's guide?

[Omnibuswoman]

Yes the scaffolding is still up as they are doing the roof now. Hopefully I can get this sorted swiftly so that the top layer of scaffolding can come down before long. 

[Wil]

@OmnibuswomanThe panels look a little expensive at £176 pretax and £500 for ancillaries seems a bit steep depending on how far from the panels the inverter will be. Check the items on ITS website for direct costs). The only thing with in-roof GSE system is that only certain panels will fit- the bigger 400W+ panels are 1900 tall compared to 1700 tall which knocks the idea of having fewer panels for greater output. Not sure if there are many panels >365W that fit, or are at a decent £/W rate, but happy to be corrected.

[Roger440]

On 31/01/2023 at 08:34, Omnibuswoman said:

My experience with Western Power was that they initially quoted me almost £15k for something that, when challenged, may not have been justified. I spent a lot of time gathering information about local loads on the line as I was convinced they were wanting me to fund a local infrastructure upgrade that was already badly needed. 
 

After asking them for detailed figures on this, as permitted under the relevant regulations, they dropped the cost to £950. It’s worth taking a close look at what they are quoting for and it’s necessity for your project. 

 

Mine was 15k too.

 

However, the exiting single phase transformer serves only my house and next door direct of the 11kv. So to have 3 phase, it needs a new transformer. So i can understand it will get expensive.

 

They also claim it needs a new pole to carry rthe weight. Not quite so convinced by that.

 

I think i'll have to do without. Im not paying for a new transformer.

[Seren161]

Lots of useful info on here.. we got a smaller system on 3 phase ..all installed now.. Still don’t know loads about it though. PM if you want to see our quote for comparison.

[Omnibuswoman]

16 hours ago, Wil said:

@OmnibuswomanThe panels look a little expensive at £176 pretax and £500 for ancillaries seems a bit steep depending on how far from the panels the inverter will be. Check the items on ITS website for direct costs). 

Thanks Wil. Yes I asked our builder to negotiate the company down a bit, and he then mentioned that his 10% has been included in the quote, which is in our contract. My irritation is that it seems that the original company is charging their full rate plus our builder’s 10%, even though they have an existing relationship with each other, and he is not getting the usual trade discount that would absorb his cut. I’ve also  asked him to seek other quotes so we will see if they come back any differently. 

[Dillsue]

Just get the trays and internal cabling installed now and do a second fix for the panels and inverter once the builder has finished. If youre under pressure to get the scaffold down you may be rushing into a full install thats not right for you technically and cost

[CalvinHobbes]

On 28/01/2023 at 12:19, Omnibuswoman said:

 

Just watched the video - a perfect idiot's guide to how this works. So in effect, it matters not how we set up the house demand across the three phases as long as we have a vector sum meter totting up total in and total out. 

What did you do in the end up?