Solar PV Peak Output?

jamesingram

The MCS online cert. process asks only for DNC
DNC = max AC output of inverter as per Ofgem definitons

SSE only ask for DNC other DNOs ask for TIC also .
reading definitions makes it easy to presume TIC= DNC also
check Navitron forum for more info , I'll see if I can find the link to
Ofgem definitions of various terms.
I have considered the views of others that I believe to be far more knowledgable than me on the subject and agree with there view .

jamesingram

grumpyoldsteve wrote: »

Surely fitting more panels just to maximise FIT return from an otherwise less than ideal roof orientation is not a very "green" thing to do?
Surely the best use of the FIT budget is to generate as much power from the least number of panels possible, ensuring the best use of the Earth's resources needed to produce these panels and ensuring that each panel becomes carbon neutral at the earliest stage.

hi , steve , i see your point but...
the Fits tariff levels are something created by a government based subsidy mechanism, it has nothing to do with efficient design.
there is plenty of debate regarding whether FITs is an efficient use of funds to achieve a goal, that is a different issue.
but to maximize resource use to achieve maximum energy returned on energy invested (EROEI ) designing an efficient Pv system should not be restricted by subsidy cut off levels.
Installing a sufficient no. of panels, relative to site situation, to maximize a specific inverters output is just efficient system design , nothing more than that.
cheers Jim

Solar_Novice

Hi Hobbo,


My father has a 2.66kW east-west split and we don't feel that the system will ever generate its max possible peak. As the sun gets higher however, he is beginning to get better peaks and also the benefit from longer days of harvesting. The max peak charge from the system so far seen on the display was 1450kWh. If it will help you can see our statistics including February here

http://www.devon-solar-panel-installation.onfocus.co.uk/tag/generation-stats/


I have a south, south-east array of 2kW capacity and although I reported peak figures on my blog of 91% (1821kWh), I have now seen the inverter hit its optimum yield in March!

Numbnuts

Martyn1981 wrote: »

Any chance you can post the exact model of inverter you have. Better still if you can look at the ID sticker on the side and give it's full model. E.g I have a SB2500HF, but there is also a simpler SB2500, and a better SB2500TL.

I'm wondering if you don't have dual MPPT, or if you do, if the strings haven't been wired correctly. I'm only guessing, but if both strings are going into one port, then your inverter may be ignoring the lower voltage string completely.

Anyways, post back and we can have a good thunk!

Mart.

The lowest TL model is a 3000TL

Models 3000TL 3600TL 4000TL 5000TL etc these sll have DUAL MPPT

Numbnuts

jamesingram wrote: »

The MCS online cert. process asks only for DNC
DNC = max AC output of inverter as per Ofgem definitons

SSE only ask for DNC other DNOs ask for TIC also .
reading definitions makes it easy to presume TIC= DNC also
check Navitron forum for more info , I'll see if I can find the link to
Ofgem definitions of various terms.
I have considered the views of others that I believe to be far more knowledgable than me on the subject and agree with there view .

Most local DNO will accept a G83 Cert for an inverter and a SMA 5000TL is g83.

so do YOU install above 4kwp and cap inverters to 3.68kwp

??? please confirm yes or NO

Martyn1981

!!!!!! wrote: »

The lowest TL model is a 3000TL

Models 3000TL 3600TL 4000TL 5000TL etc these sll have DUAL MPPT

Does the 3000TL now have dual MPPT? If so that would be a better option for Wensleydale than the 3600TL as he'd have more chance of convincing his installers as it would be a little cheaper, and close to ideal for his (or her) system size.

Mart.

jamesingram

Martyn1981 wrote: »

Does the 3000TL now have dual MPPT?
Mart.

Old one doesn't , heard new model may

jamesingram

!!!!!! wrote: »

Most local DNO will accept a G83 Cert for an inverter and a SMA 5000TL is g83.

so do YOU install above 4kwp and cap inverters to 3.68kwp

??? please confirm yes or NO

Yes or go for pre-inform g83/2 for installs DNC 3.68-4+ kWp

so far only done g83 the simpler post install paperwork, without additonal costs. Not had a client for a larger sys. yet.

wensleydale

EricMears wrote: »

Regardless of how many strings such an inverter might support, your screen dump shows pretty conclusively that it's only actually using one string - which (as Martyn has pointed out) would need two cables entering the inverter box. Even if you have 4 cables (two from SE & 2 more from SW) it would seem that they're joined inside the terminal box rather than feding two separate parts of the circuitry.

Afraid Martyn is also guilty of one of those 'errors' to which our forum seems to be prone. I'm absolutely not an 'expert' nor do I understand it any better than he does :rotfl::rotfl::rotfl::rotfl:

I am however quite happy with looking at Sunny Explorer output windows - hardly an hour goes by when I'm not viewing mine:eek:


My limited expertise is sufficient to agree with the other posters who have pointed out that to host two separate installations pointing in different directions on the same string is a recipe for disaster.

Afraid my 'expertise' isn't even sufficient to differentiate between a string and an MPPT. I'd always thought of them as equivalent terms. OMG - another 'error' !

Thanks for the help on this guys- 2 inverters now installed and things seem to be a lot healthier- particularly at the start and end of the day.

Appreciate all the input.

Martyn1981

wensleydale wrote: »

Thanks for the help on this guys- 2 inverters now installed and things seem to be a lot healthier- particularly at the start and end of the day.

Appreciate all the input.

Hiya Rich, glad it's been sorted.

Can I be nosey, and ask what inverters did you end up with? Did the installers stick with SMA, I've got my fingers crossed for 1300TL's as they're a little bit more efficient that SB1200's (which I've got one of).

All the best, and I hope it's sunny with you.

Mart.