Renewables: "talking 'bout my generation"

Oscargrouch

tunnel wrote: »

Mr O, national wine drinking day today(isn't everyday?), I'm guessing you'll be partaking? I am

Not wrong there Tunnel; home from work at 21:15 third bottle of red going down really well (not rushing it): I like to take part in these national traditions..

A good 3.6 O's for here today..

jonokimber

Hello everyone, first post so go easy :-)

I think I have a problem with my installation and peak power output. On a nice sunny day the other day my 4kw (14 x 285w panels) system peaked at 2.6kw and the generation curve appeared to be pretty flat on the top, certainly starting to flatten out at about 2.5kw. I compared my curve to a friend who has an almost identical system (14 x 285w panels) at a similar latitude to me and not to far either. His system peaked at 3.6kw on the same day and the gen curve was nice and round all the way.

I checked a previous reading from my generation meter reading from January 16th to today's final reading. Since then my generation meter has moved on by 200.8 kWh and my Growatt inverter wifi dongle shows 200.5 kWh generated since then so i think it's accurately sending the right figures to the Growatt server.

I have a two string setup on a lovely roof with about 40 degree slope, about 40 degrees east of south. no shading.

Here's a picture of the gen curve, does anyone think it's flat? Oh, it seems i cant post a link so that's a shame. maybe i need to post a decent quantity of posts before i can post a link?

Thanks

Jon

Oscargrouch

jonokimber wrote: »

Hello everyone, first post so go easy :-)
Here's a picture of the gen curve, does anyone think it's flat? Oh, it seems i cant post a link so that's a shame. maybe i need to post a decent quantity of posts before i can post a link?

Thanks

Jon

Welcome Jon; think you will find to post photo's you have to use something like 'tiny pics' as a host and then use the link from them on here...early days to make a sudden judgement on your system, you need to see how things pan out for a few weeks with your friend. Is his roof/roove the same pitch as yours? Get in touch with your installer, and get them to check it out....

Martyn1981

jonokimber wrote: »

Hello everyone, first post so go easy :-)

I think I have a problem with my installation and peak power output. On a nice sunny day the other day my 4kw (14 x 285w panels) system peaked at 2.6kw and the generation curve appeared to be pretty flat on the top, certainly starting to flatten out at about 2.5kw. I compared my curve to a friend who has an almost identical system (14 x 285w panels) at a similar latitude to me and not to far either. His system peaked at 3.6kw on the same day and the gen curve was nice and round all the way.

I checked a previous reading from my generation meter reading from January 16th to today's final reading. Since then my generation meter has moved on by 200.8 kWh and my Growatt inverter wifi dongle shows 200.5 kWh generated since then so i think it's accurately sending the right figures to the Growatt server.

I have a two string setup on a lovely roof with about 40 degree slope, about 40 degrees east of south. no shading.

Here's a picture of the gen curve, does anyone think it's flat? Oh, it seems i cant post a link so that's a shame. maybe i need to post a decent quantity of posts before i can post a link?

Thanks

Jon

Hiya Jon. Lot's to think about there and the short answer, do as Oscar says, take a bit of time and see how it all goes.

Longer answer:-

Have a look at the inverter screen and see if both strings are reporting (roughly) the same info volts, amps and watts. they might not be identical, but should be fairly similar unless there is shading.

Take a look at the roof a few times during a nice day, and make sure there's no shading, it should be more obvious at this time of year when the sun is lower.

Given your orientation of SE, is your friends identical, or more southerly? Total generation against south facing won't be too much less over a whole year, but could explain a bit of a difference at this time of year both kW's and kWh's.

Have a play with PVGIS (see section 5 of FAQ's), and find out the estimated annual and monthly generation. Remember though to take monthly weather into account before thinking you've generated too little (or too much). [Leave the defaults, put 4 in the kWp box, 40 in the pitch and -40 in the Azimuth. Zero right down to your house and pop a pin on it.]

One thought is that as the sun rose and generation grew, it then started to move away from your orientation, but held onto 2.6kW as it grew higher and better travelling through to south.

For comparison my 3.58kWp ESE system has only hit 2kW so far this year. But not a great guide as it's smaller, shallower and further from south ...... but hopefully some reassurance.

Early days, don't panic.

Mart.

jonokimber

Thanks Mart and Oscar.

I'll be getting my head back up in the loft later as it looks like we'll have some nice sunshine. A glimmer of hope for me is that every decent day the maximum peak does seem to increase by about 30watts, as would be expected for the sun that is rising higher every day. Maybe it's just the nature of my system and i'm glad i've taken the step to sign up here as the quick respinse was encouraging.

My first go at PVGIS correlated quite well with my installers FIT estimate for the year and January's actual production so maybe things are just fine?!

Regarding posting a picture I need to be able to post a link and new posters can't do this. I'll keep posting until the forum realises i'm a human and not a robot.

Cheers

Jono

Rheumatoid

jonokimber wrote: »

Hello everyone, first post so go easy :-)

I think I have a problem with my installation and peak power output. On a nice sunny day the other day my 4kw (14 x 285w panels) system peaked at 2.6kw and the generation curve appeared to be pretty flat on the top, certainly starting to flatten out at about 2.5kw. I compared my curve to a friend who has an almost identical system (14 x 285w panels) at a similar latitude to me and not to far either. His system peaked at 3.6kw on the same day and the gen curve was nice and round all the way.

I checked a previous reading from my generation meter reading from January 16th to today's final reading. Since then my generation meter has moved on by 200.8 kWh and my Growatt inverter wifi dongle shows 200.5 kWh generated since then so i think it's accurately sending the right figures to the Growatt server.

I have a two string setup on a lovely roof with about 40 degree slope, about 40 degrees east of south. no shading.

Here's a picture of the gen curve, does anyone think it's flat? Oh, it seems i cant post a link so that's a shame. maybe i need to post a decent quantity of posts before i can post a link?

Thanks

Jon

My system maxes out around 3.6 kW

Crowmann

I had a very similar initial problem - I just did not think the system was working as it should.


It wasn't, despite being signed off as fully correct the inverter was recording vastly different Volts and amps on the two identical strings.


After some reluctance on the installers part the inverter was swapped and now balanced and working well.


Peak watts on my monitor have been just shy of 3.9kw.

EricMears

jonokimber wrote: »

Regarding posting a picture I need to be able to post a link and new posters can't do this. I'll keep posting until the forum realises i'm a human and not a robot.

MSE won't actually say exactly how many posts it takes before you're trusted to post links (I think that's to deter would-be spammers from auto-generating just the right number) but it's not usually a lot - perhaps a dozen or so ? For much the same reason, you can't send a PM to another forum member and ask them to post a link on your behalf. However, you can (sort of) post links by dong something like this :-
(3ws), dot , Mywebsite domain name, dotORGdotUK, slash, filename

As long as it doesn't try to form a valid url it will probably be allowed. A mod (i.e. a real live human being) might look at it later and would have the power to zap it but probably wouldn't bother if it looked a reasonable addition to a thread.

Oscargrouch

jonokimber wrote: »

Thanks Mart and Oscar.
My first go at PVGIS correlated quite well with my installers FIT estimate for the year and January's actual production so maybe things are just fine?!
Regarding posting a picture I need to be able to post a link and new posters can't do this. I'll keep posting until the forum realises i'm a human and not a robot.
Cheers
Jono

These two links may be of use to you:-

http://wattson.energyhive.com/dashboard/oscarsenergy
http://suncalc.net/#/52.273,-0.8756,9/2016.02.19/12:02 Satellite image button (top left) is just about doable. Sure you will work it out....

Rheumatoid

Will be close but could be on to a 5-O

4.5 at 14.45 with clouds appearing. the tension mounts