change/upgrade solar pv system

[solargenerator]

would rather change the layout myself.
have scaffold tower, roof ladders and by now the knowledge.

 

[whinmoor]

would rather change the layout myself.
have scaffold tower, roof ladders and by now the knowledge.

Be careful! It's not really your job to rectify their error.

 

[solargenerator]

2 years since install

 

[Beavstro]

I would be seriously careful about changing an existing set up, I helped my company put a wind turbine through the MCS scheme ( which all products have to have in order to be eligible for FiT) and they were very clear that the product tested and its set up is what is eligible. For example your panels and the inverters (including how the inverters set up) must be the same as what was tested for the MCS certificate. Thus any change to the set up is not eliagble for the FIT as it is not what was tested.

Best option here is to talk to your installer of the product and see what options they have, as the panels MAY be able to be used with other parts without affecting eligibility of the FIT. As I'm sure you know, if you lose your FiT you will lose a lot of money!

 

[SolarCity]

Bad design. If the firm is still going then I'd give them a call and ask for their thoughts.

 

[solargenerator]

thanks for all your inputs.

power optimisers behind panels with original invertor sounds a good bet?

 

[Vegelen]

1) Your PVI-3.6-TL-OUTD Inverter is larger than it needs to be for your present setup.
2) If your Romag panels are Vmpp 30.6V per panel > 7 East facing = 214.2 V, 2 East + 4 South = 183.6V.
3) The voltages on each of your strings are operational but not optimum.
4) Putting 2 East with 4 South will reduce the amount you can generate on the 2nd string.
5) It would be benefitial to have 9 East facing panels connected to 1 string, but what would you do with the 4 south facing panels you've currently got, their voltage wouldnt be high enough for the 2nd string on a PVI-3.6-TL-OUTD ?
6) Aurora Optimisers may be benefitial, but at what price. What will you gain for your investment?
7) PVGIS indicates 9 East facing 235W panels in Durham (2.115 KWh) could generate 1400 KWh.
PVGIS Indicates 4 South facing panels 235W in Durham (0.94 KWh) could generate 784 KWh.
Thus 2184 KWh is the likely theoretical amount you'd expect to generate with a properly designed system.
8) Solar system design isn't always straightforward because of the roof types, spaces, orientations & inclinations installers have to work with.
9) Do I think the installer designed your system to its optimum, no?
10) How much could you gain by altering this system? 2184 KWh V 1815 KWh (17%)?
11) In reality solar optimisers are unlikely to generate what you'd expect because of the low combined south facing panel voltage, shading issues, greater efficiency losses etc.

If you had more roof space to install more south facing panels, you could seperate your East facing panels from your south onto individual strings with higher combined voltages that would improve things.
It may be best for you to accept what your generation is and be pragmatic about it.
Many people may generate more than you but how much of it do they productively use 33%?
How can you better utilise the energy you generate to exceed typical usage?

 

[solargenerator]

View attachment ConfigurationReport (3).pdfit may be possible to move one of the nine panels to the south orientation to give a 8 x 5, might be a squeeze but with a couple of joist hangers extra to support the panels at the foof edge.
with the 5 south panels on a voltage reduction of only 161v.

 

[Vegelen]

It is going to cost you more to change this system, than what you'll benefit from it.
Make better use of what you generate.

 

[solargenerator]

looking that way.

there maybe something around the corner.

will not stop looking for improvements.

 

[Worcester]

Using the power-one optimisers, looking at the datad sheet, you effectively configutre it all as one string, as each optimiser works as it's own mpp tracker.

If you do anything, that may be the most cost effective solution.

 

[Earthstore]

Why not change the 4 panels for Sunpower, or Panasonic, or was it jetson that are 50v?
Then if the inverter allows all the others could be wired on one string.
It may be more cost effective this way, without the potential of having to get back up on the roof every few years if you have any reliability issues.

It may need some careful system design, but then it should have had that in the first place.
Just a thought, that's all.

 

[Vegelen]

Why not change the 4 panels for Sunpower, or Panasonic, or was it jetson that are 50v?
Then if the inverter allows all the others could be wired on one string.

H J Solar are inexpensive, decent panels with a reasonable temperature coefficient:

H J Solar 250W HJM250M-32-BL or HJM250M-32 (Vmp 50.6, Voc 60.5):

http://reseller.segen.co.uk/reseller/docs/HJ Solar HJM250 255 260M - Datasheet Black Modules.pdf

Which solar panels were most affected by shading, was it the south or east or both?