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[Moz39]

Hi everyone,

My husband & I are self builders.

This site is recommended on the buildhub forum as a mine of information for complete novices.

We are trying to find some no axe to grind info on PV installations.

 

[binky]

what do you want to know?

 

[Moz39]

Hello Binky,

We are looking to install a 4kw PV, in roof system on our new build.

We have to have black panels because in a conservation area & a condition of planning.

I am very confused about string inverters & micro inverters.

Some of the quotes we have include them & some say it is better to put the money into a good quality string inverter.

We have a SSW facing roof with no real shading.

Thanks for any advice.

 

[binky]

string inverter every time for me.

Micro-inverters and optimisers (i'm sure someone will have quoted you for Solaredge) just add failure points to the roof. The panels should last 40ish years, these gadgets last about 20 suppossedly. This means you will have to dismantle the array to replace these gadgets. They do have a place, where heavy shading is an issue, but then the system would possibly be not worth installing, unless you have to. SMA inverters also have a different algorithm that compensates for shading, as these are cheaper than gadgets on the roof, there is little point in using Micro inverters or Solaredge.

In roof, best system is GSE. It's French and well made / quite simple to fit. The french offered higher FiTs for in-roof systems so have developed the best.

Decent inverter is worth spending money on, the only cheapish inverter I would use is Samil, with an extended warranty it's still cheaper than SMA. They seem to work well, albeit the website 'portal' is rough, not that you actually need to link to a portal, but it's useful.

With regards to panels, look at low irradiance performance. They all work well in full sunshine, but it's how they work in winter / poor light conditions that determines the difference in quality. If you can afford them LG is the dogs do dahs in my opinion, just a bit pricey.

4 kW? Can you get more on the roof? As a new build talk to your DNO about your leccy connection to the grid. I am assuming you are getting a new supply, so it should be no problem to get a slightly upgraded connection that will allow more than 4kW

Rough price guide ofr in-roof 4kW, Circa £7-8k. It costs more than on-roof, but then it saves you slating / tiling that section.

P.S. most batteries don't pay for themselves. Fit a gadget like Solic 200 to divert surplus energy to hot water tank - very good reports from my customers on these.

 

[Moz39]

Hi Binky,

Thank you very much for the info.

I have just received a quotation that seems to include most of the elements you have recommended.

14xLG320 Neon, SMA SB 3.6 inverter, In roof mounting, generation meter, isolator, full installation testing & handover, MCS registration & certificate, 5 yr insurance backed warranty & 5 yr solar performance guarantee & solic 200 £5965 ex VAT

Price doesn't seem too bad & we will not be paying VAT as a new build.

Western Power have given us an option of a duel connection , but I am not entirely sure what it means.

Best Wishes

Moira

 

[binky]

good price for that spec.

I would Google the company to check reviews etc etc, just in case.

Duel, 2 phases I think, so you could have say 8kW of panels

 

[Moz39]

Binky,

I am so grateful for your advice.

Another supplier has just thrown something else into the mix that I hadn't heard of.

It is a Solaredge power optimiser series inverter.

Are you familiar with this?

Sounds expensive.

Regards

Moira

 

[binky]

Don't bother, it sounds great, but in reality I have found this system to be unreliable. I am currently investigating a system that has 2 optimiers that won't register with the inverter, so effectively it's 2 panels down. Ultimately this systen introduces electronic components to the roof, ie more things to fail. Their life is meant to be 20-25 years, so again you will have to spend money on accessing the roof to remove and replace the optimisers, where as the panels will last 35-40 years with no issues. I have somewhere got the much quoted Photon International report on Solaredge. Photon International are a well respected tester and solar industry publication. Their test to see if SolarEdge is any good, has a flaw in that they compared results against a Grade B inverter ( never did understand why) so it compares relatively well. However if you fit an A grade inverter like SMA, it clearly isn't going to offer any benefits, and the real use for optimisers is for arrays with shading issues. SMA also has shade compensation built in, making optimisers even less of a good idea given that SE is dearer than an SMA. see video below.

I maintain and monitor school solar systems for Plymouth Energy Community. 3 companies were involved in installing these, 1 used Fronius Inverters, 1 used Solaredge, and I used SMA. To date my systems have been the most reliable, outputs don't vary much between the 3, but Solaredge has definetly been the least reliable.

I would recommend you have a hot water tank linked to a Solic 200 to use surplus energy for hot water.





View attachment SOLiC 200 Brochure.pdf

 

[Blue Duck]

Jeez... @binky people should be paying for this quality of advice that will potentially save them thousands in the future! 

 

[binky]

Save thousands and make thousands. I've designed and fitted nearly 1 million kW of solar panel systems. Over the many years of fitting solar, I've always found I do well with practical people with an engineering background. Solicitors and other office worker types always seem to use companies with proper 'sales rep types'. I've always wondered why that is ( may be I should buy a cheap suite )

 

[Moz39]

Hi Binky,

Thank you once again.

I thought it might be the case.

I was getting the real hard sell from the chap at Solar Plants.

The quote I mentioned before from a different supplier includes a solic 200.

Blue Duck is right, your advice is so valuable as it is un biased.

When trying to find out info on this everyone is trying to sell you something.

Best Wishes

Moira

 

[Lurch]

may be I should buy a cheap suite

I'm moving soon and won't be taking all the furniture with me, £50 and you can have the suite as long as you are OK with picking it up.

 

[binky]

:slap always did get a 3 piece whistle and flute,  and furniture mixed up :slap :slap

 

[binky]

Hi Binky,

Thank you once again.

I thought it might be the case.

I was getting the real hard sell from the chap at Solar Plants.

The quote I mentioned before from a different supplier includes a solic 200.

Blue Duck is right, your advice is so valuable as it is un biased.

When trying to find out info on this everyone is trying to sell you something.

Best Wishes

Moira

the industry is a bit desperate to generate sales, so installing Solaredge to gain 25% higher output for a mere £4500 is a common ploy, along with batteries that might just pay for themselves before they fail. Double glazing salesmen at their best. It's a total shame, whoever wrote the MCS scheme did try hard to shut out charlatans, but where there is money there is a winker trying to sell sand to Arabs. I spend a lot of my time now repairing dodgy installations and replacing failed cheap nasty inverters. It really pees me off, renewable energy is a damn good thing, and can certainly be  made to work well for people, but....... :shakehead .  Please reoprt any hard sales tactics to RECC who these people should be registered with.

whatever offer you aare thinking of opting for, let me know the details and I'll give you an opinion ( I'm not always right, but try firkin hard to be!  )

 

[steptoe]

It's not often I agree with @binky

But mostly nowadays my only dalliance with solar is fixing fk ups left by previous installers, 

Its ridiculous some of the set ups some domestics have been left with. 

 

[binky]

:Chairfall