Daily pv production

LimerickCity · 12-01-2022 4:40pm

When can you expect to see the optimum performance from the solar pv.

We have a small system, just 3kwh installed since late November.

The max I have seen it get up to is about 1.7kwh in terms of monitoring.

It has generated almost 7kwh today but has never gone beyond 1.45kwh at any stage.

They are perched on the roof with no obstruction in full sun.

bullit_dodger · 12-01-2022 4:57pm

Hey up mate. The highest production is a factor of a couple of things.

the orientation of your panels
the time of year
and finally the time of day

If you panels are facing exactly due south, then they will generate max output at "solar noon". Solar noon of course isn't at 12pm, as we're a bit further west than London, so in Lmk (being 9 degrees west) solar noon is about 36 minutes later so in about 12:36. If your panels are facing a little further west (say 195 degrees) then the time would be a little later in the day, which you can see from your chart above. So I'd suspect from the chart that you panels are orientated that way.

As the sun climbs higher and higher in the sky as the seasons change towards summer, your panels will generate more and more as we get towards June - after that then they'll slowly start to produce less and less until December and the whole cycle starts again.

The changes per day in output are quite small this time of year, you have to compare week by week at best, but by mid March you'll be probably 2.2-2.3Kw or so

Bif · 12-01-2022 5:10pm

https://www.boards.ie/discussion/comment/118462522#Comment_118462522

Great post. I imagine the angle (pitch) of the roof can impact a little on output as well.

LimerickCity · 12-01-2022 5:20pm

https://www.boards.ie/discussion/comment/118462522#Comment_118462522

Thanks for the update. Much appreciated as always :)

The panels are South West facing at 35 degrees.

bullit_dodger · 12-01-2022 5:21pm

https://www.boards.ie/discussion/comment/118462613#Comment_118462613

Absolutely. And that's why you see those solar tracker moving the panels around to face the sun like this jobbie changing the pitch angle from day to day as well as east to west. If you've got 15 mins or so this gives a decent intro.

How Solar Trackers Work - YouTube

Great for professional solar farms, for us though the cost in the gimbles etc and the fact that most of us bolt ours onto the roof it's a non-runner, and that's ok. Our fixed panels on the roof get like 60-70% of the max power thats there.....it's worth the drop in efficiency for a simpler system. We don't have the problems of gusts catching the panels and behaving like a "sail" on the roof etc.

unkel · 12-01-2022 5:28pm

Over 10kWh today. Not bad for the first half of January! Saw 2.3kW at around midday. Down to 10W now, sunset is already kicking in

Zzippy · 12-01-2022 6:00pm

Good day again today, 11.72kWh. Slight interruption at lunchtime when ESB Networks arrived to install the smart meter 😏. Presumably they take a final meter reading on the old meter? The new one is still at 0.0 a few hours later 😀

Bif · 12-01-2022 6:57pm

Another good day also. I guess this is exceptional weather for January.

Jonathan · 12-01-2022 7:14pm

Cracking day; 11.9kWh

paulbok · 12-01-2022 7:39pm

15.4kw today

idc · 12-01-2022 8:43pm

Obviously not as good as all you lads but highest day this month with 4.8kWh. Shading and angle of my south west panels really limits my winter generation 😕

bullit_dodger · 12-01-2022 8:50pm

Beaten badly again. 4.3Kwh off a 5.3 Kwp (E/W spit) in Dublin. I reckon another month/6 weeks of hurting

....and then I'll have my day. Oh yes - I'll have my day! Just you wait ! LOL !!

ECO_Mental · 12-01-2022 8:55pm

Tipped over 20 kWh today...💪 tbh most of it went back to line the pockets of Mr. ESB 😪 I had all my washing done yesterday..

Good start to the month overall though.

slave1 · 12-01-2022 9:03pm

gonna have to ignore this thread for a few months...

reklamos · 12-01-2022 9:17pm

10.5kWh today it is good start of the month

THE ALM · 12-01-2022 9:27pm

is like solar top trumps😂 although bif has us all beat.

Best day with us so far with all generated being consumed by the Eddi and Zappi over the last couple of days which equates to 160km of free driving so happy out.

Bif · 12-01-2022 10:49pm

https://www.boards.ie/discussion/comment/118464023#Comment_118464023

😂. It is irrationally satisfying (beyond the monetary concerns involved) to fill the car with solar energy.

irishchris · 12-01-2022 11:01pm

20.7 kWh here in galway today.

Cracking week but tomorrow sadly not looking as good

bullit_dodger · 12-01-2022 11:03pm

Dublin is reporting (according to the Met Eireann site) that tomorrow will be fractionary better than today. We'll see, but sounds promising.

THE ALM · 12-01-2022 11:15pm

https://www.boards.ie/discussion/comment/118464544#Comment_118464544

That is for sure. Looking forward to our first leccy bill since installation, not be something I'd normally think 😄

THE ALM · 13-01-2022 5:17pm

Bit of a swing from the highs of yesterday and the rest of the week not looking much better.

Bif · 13-01-2022 6:02pm

The highs and lows of PV in Ireland!

paulbok · 16-01-2022 7:23pm

Decent day today despite the clouds, 10.9 kw.

bullit_dodger · 16-01-2022 8:05pm

Yeha, not a bad old day considered.

Tomorrow (Monday) and tuesday looking good according to the forecast.

Bif · 16-01-2022 9:14pm

Good day for the PV.

Jonathan · 17-01-2022 10:50am

Expecting good production today due to clear skies and sub-zero temperatures.

Perfect generation curve so far, and already generating in excess of 1kW.

THE ALM · 17-01-2022 11:32am

Looking like a good day indeed, tipping 2kW at 10:30 so glad the car is plugged in.

A few peaks and troughs yesterday but about the third best day of the month so far.

garo · 17-01-2022 5:42pm

Just catching up on this thread. Like the rest of you E/W installs this is the time of the year my production is hurting. Got 3.7kWh today so highest for the year so far. But thanks to the DIY 10kWh battery and night time charging my grid import for the first 16 days is 61 day/349 night.

@bullit_dodger Convention is to take the angle of incidence as 0 when the sum is directly overhead the panels so you'd be taking cos not sine. But yeah the increase in theorectical production is only about 1% per day at this time of the year.

Let me get a pet peeve out of the way. kWh is amount of energy produced (in a day/hour/year) and kW is the instantaneous production. So if your panels give you 1kW for an hour you have produced 1kWh.

THE ALM · 17-01-2022 5:50pm

Just about done for the day, drops off quickly for the last 30mins as there is a small hill which cuts off that last bit of productions but still the best day so far.

Jonathan · 17-01-2022 5:56pm

https://www.boards.ie/discussion/comment/118488083#Comment_118488083

Finished out the day with 13.1 kWh.

https://www.boards.ie/discussion/comment/118490404#Comment_118490404

If that was aimed at me, I know the difference. My panels were generating over 1,000W at the time. I hadn't generated 1kWh at that stage.

Daily pv production

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