PV systems with modules on south facing & South west facing aspects of roof

[Graeme Harrold]

It will work a treat, think of the 4000TL as 2 inverters in 1 box. Its got a good DC range with low start voltage.....

Download the SMA software and check out your setup and it will show the suitability of the panels on each string. Also get the Sunnyexplorer software as I always pass this on with a USB bluetooth dongle (dont forget to change the installer password)

 

[BathKate]

Hi guys,

Thanks for your help! I'm getting wildly different stories from the 3 suppliers I've had quotes from which is making it rather difficult!

In total we have 3 usable sections of roof for Solar thermal and pv. The largest is SE facing (9 units) then there is a SE and a SW available at about 7 units each. On the SE facing roofs, the smaller one is set slightly forward of the bigger one - say 2m? Which 2 roofs would you say are best for PV?

One supplier has also stated that we MUST have Enecsys micro-inverters, are they more expensive? is it worth it?

Thanks again

 

[Worcester]

Are the two SE roofs at the same angle / pitch and same orientation, if so (and shading doesn't affect either group) then the panels on the SE roof can be combined onto the one tracker, if not then you'll effectively need three trackers, and with the latest enecsys 360's that should work out cheaper than multiple string inverters (a dual MPP and a single MPP).

Enecsys Micro-inverters work out to be the correct solution, where you need 3 trackers, or the shading issues are a big problem.

Yes they will cost more, however you'll get a system that works.

You have to be Authorised by Enecsys to design specify, purchase and install their micro-inverters, as they are installed and configured differently from a normal string inverter.

 

[BathKate]

Hi,

Thanks again for your help - it's much appreciated.

Yes, the 2 SE roofs are at the same pitch and orientation, the only potential shade issue is the small SE roof onto the larger SE roof - but I think it should be ok.

How much extra does it cost to have an inverter like the 4000TL rather than a bog standard single one?

The 3 quotes I have for the same building range from a capacity of 1.92kWp to 3.36 kWP, all using the same plans to quote........ and bizarrely the quote in the middle uses all 3 roofs rather than just 2. The price range is £10k to £13600 with the largest system at £10k (!) but only using a single inverter. All the quotes use Sanyo panels due to the restricted space, using 240, 245 and 250 W panels.

Cheers

 

[Ramjam]

Don't forget that Western Power have demanded the immediate disconnection of Enecsys micro inverters. The inverters were type tested G83 in isolation and not connected together as a system, their characteristics change with multiple units and collectively would fail G83, WP are demanding a re-test and have ordered that all existing systems be switched off....as I understand it....correct me if you know better!

I got enecsys authorised but when you look into them in detail it's shabby and they're not very good...opinion!

 

[SolarCity]

The 3 quotes I have for the same building range from a capacity of 1.92kWp to 3.36 kWP, all using the same plans to quote........ and bizarrely the quote in the middle uses all 3 roofs rather than just 2. The price range is £10k to £13600 with the largest system at £10k (!) but only using a single inverter. All the quotes use Sanyo panels due to the restricted space, using 240, 245 and 250 W panels.
Cheers

Difficult to evaluate the systems without knowing the details. If there is a single inverter being used then it must have a dual MPP tracker like the SB4000TL. If not then the system is very poorly designed.

 

[BathKate]

Hi Biggs,

Thanks for the reply. I should get more details on exactly what is being proposed tomorrow, so I'll get back to you then. Thanks again, happy Sunday!

 

[Brighton Solar]

Hi Kate,
Have you considered using Solar Edge components? By using their power optimiser units and inverters, you can put all the panels on one string. The optimisers will take the MPPT out of the inverter and into each individual panel. In your case, assuming that you had all 23 panels (which seems alot!) installed on the different roofs, you would have the benefits of 23 different strings with a constant voltage of all 23 panels in one string across the entire array!
This is a fairly new system, but it sounds that in your case it would be perfect. It also has the advantage of inbuilt monitoring software for your computer.
If you have further details, I will look into the best array configuration?