Newbie

[Earthstore]

I am sitting on the fence here, however has any body ever mended a car when we have so many garages? Decorated the house when we have so many decorators? fitted a kitchen when ther are so many kitchen companies? And the list goes on.

The OP has been polite and is paying for specialist help, I may not agree with what he is doing but give the guy a break, I have seen some systems installed by professionals that are not fit for purpose, there is yet another recent one on here "should I be worried" .
Maybe some are unhappy because things are tough, or maybe they have valid points, but there is no need to lose your manners.....

 

[SolarCity]

Okay, points have been made. Can we now stick to the original topic please?

 

[Steve_rutland]

Popped in to see my install company today and they have been very helpful with my G59 form. Also spoke to the council regarding the Part A structural side and they are sending out a surveyor to do the check. Just need this wind to drop a bit now!

 

[AndyOz]

Best of luck (if you need it) with the install Steve. Keep us informed on your progress.

 

[Steve_rutland]

Thanks Andy. Need some luck with this weather lol!

 

[Steve_rutland]

Well got the first row of 7 roof brackets up. Did it via a ladder but have a scaffold tower arriving this weekend for the rest if it. Lot safer and less upping and downing for grinding! Getting there ;-)

 

[Steve_rutland]

Scaffold has arrived, so just need some time and less snow! Quick question,
My panel supplier have some slightly lower voltage panels and this would allow me to use 1 string. Is it preferable to match ( as close as possible ) the max voltage to my inverter, or just go with 2 strings and halve it?

 

[SibertSolar]

The inverter will have an optimum MPP tracking voltage range, taking into account the impact of temperature coefficients of the panel. Most MPP trackers will have a "sweet spot" range of efficiency at varying voltages. How you configure the panels to best suit the inverter capabilities depends on the inverter, the panels and the environmental/installation specifics. This can be calculated manually if you have all the info but easiest way is to use the inverter's configuration software. Any decisions made on "best judgement" come down to the experience and knowledge of the system designer.

 

[Earthstore]

I have just re read the whole thread out of curiosity really,

The comments from sibertsolar are good advice, whatever you put up there should produce something, however, you do need to match the panels well to the inverter to get it to work the best, we do keep bleating on about system design, but people do not realise how important it is to get it right, the thing is if you install the system and it works you will never know how much better it could have been with the correct design.
Compound a little extra performance over 20 years of FIT's and energy savings and it could be a tidy some of money lost.

Also do you think you will get the FIT on your original system?

 

[Steve_rutland]

Thanks for the pointers guys. Will have to wait for the various panel specs to come through. The original off grid system is coming out completely to be replaced by this dual aspect one. Amazingly enough, my batteries are valued at £360 scrap or around £600 re-sale so they'll be up for sale soon lol. Got the structural survey on Wednesday.

 

[Earthstore]

Sounds like it is coming together, just curious, what size/make of inverter do you plan to use?

 

[Steve_rutland]

It is......slowly
They are both Ever Solar TL3200

 

[Earthstore]

Oh.

Without doing all the calculations I would have used something like an SMA TL5000, probably would have been cheaper that your 2 inverters and would probably produce more KWH, but as stated would need to do the calcs first...

Added, At a guess, your inverters are too big for an east/west split..

 

[Steve_rutland]

I can get 14 x 250w panels on each side which comes in at 3.5kw each. Both inverters cost £725 ( one was £295and the other which came with cable & isolators was £430).

 

[Vegelen]

I can get 14 x 250w panels on each side which comes in at 3.5kw each. Both inverters cost £725 ( one was £295and the other which came with cable & isolators was £430).

Make sure you buy better solar panels than the inverters - I am not impressed with your inverter selection.

Time and time again I see people with little knowledge, taking shortcuts to install cheap solar systems, cutting corners, buying crap hardware, metaphorically shooting themselves in the foot, thinking they have bought a good system, ending up with a poor underperforming system that could have been so much better if they had took the time to consult a few experts on this forum like Earthstore.

If in doubt, ask and we'll try to help.