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So how was your December?


Bobster.

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I keep a rain gauge which I check every morning. It's not 100% accurate, but checking the volume of various sizes of cones shows that it's not far off. I compare my figures to those given by the SAWS (which are averaged for regions) and I'm in the ballpark. So my figures are reasonably accurate.

OK... so for December 2022 I logged 259 mm (this is in Randburg). For 2021 - same gauge in the same location - I recorded 181.5 mm. So December 2022 (as anybody living in greater Jhb could tell you) was significantly wetter than December 2021.

PV? Glad you asked. I had 305.2 kwh generated in December 2022, 329.2 in December 2021.

Figures for 2020 were 113 mm and 374.8 kwh.

OK... me just humble computer programmer. I can barely spell "climatology", but I think these figures fit in with something I recently read from SAWS to say that SA is entering a 3rd straight year of La Nina conditions, which means more and heavier rainfall. That seems like it should mean more overcast spells.

So how was your December? After all, maybe my panels are filthy (though with all that rain I doubt it)

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2 minutes ago, Bobster. said:

I keep a rain gauge which I check every morning. It's not 100% accurate, but checking the volume of various sizes of cones shows that it's not far off. I compare my figures to those given by the SAWS (which are averaged for regions) and I'm in the ballpark. So my figures are reasonably accurate.

OK... so for December 2022 I logged 259 mm (this is in Randburg). For 2021 - same gauge in the same location - I recorded 181.5 mm. So December 2022 (as anybody living in greater Jhb could tell you) was significantly wetter than December 2021.

PV? Glad you asked. I had 305.2 kwh generated in December 2022, 329.2 in December 2021.

Figures for 2020 were 113 mm and 374.8 kwh.

OK... me just humble computer programmer. I can barely spell "climatology", but I think these figures fit in with something I recently read from SAWS to say that SA is entering a 3rd straight year of La Nina conditions, which means more and heavier rainfall. That seems like it should mean more overcast spells.

So how was your December? After all, maybe my panels are filthy (though with all that rain I doubt it)

I Live in the Vaal Triangle, I don't have a rain meter, but I can tell you that December 22, in my case as far as PV generation is concern it's been slightly less than last year.

4920 Kw of panels, 2021 December = 453 Kw/h December 2022 = 445 Kw/h

So far, my best Month in 2021 was August = 525 Kw/h 

 

 

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20 minutes ago, Bobster. said:

OK... so for December 2022 I logged 259 mm

You are a lot more fortunate than me for December then.
Have complete rainfall data for the last two years here in Parkdene.
Dec 2020 - 205,5mm
Dec 2021 - 182mm
Dec 2022 - 159mm
2021 annual Total - 920mm
2022 annual Total - 1189mm

My solar stats for 2022.
Aug was bad as my Inverter took two weeks to be repaired. I was rather lucky as there was no loadshedding in those two weeks. 😉
If it seems low monthly Load figures, that is what I use, have never wasted energy. 

image.png.6a69d199024170bfc20729c69dc9e7f5.png

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43 minutes ago, zsde said:

You are a lot more fortunate than me for December then.
Have complete rainfall data for the last two years here in Parkdene.
Dec 2020 - 205,5mm
Dec 2021 - 182mm
Dec 2022 - 159mm
2021 annual Total - 920mm
2022 annual Total - 1189mm

My solar stats for 2022.
Aug was bad as my Inverter took two weeks to be repaired. I was rather lucky as there was no loadshedding in those two weeks. 😉
If it seems low monthly Load figures, that is what I use, have never wasted energy. 

image.png.6a69d199024170bfc20729c69dc9e7f5.png

Yes, indeed your consumption compared with my household is minimal. I average 22 Kw per day. and get an average of 15 Kw from my solar system.

Also, my battery use during that year was about 750 Kw/h

image.thumb.png.b0a46d832cd0b81481e293df67976044.png

See attached 1 year dashboard.

image.thumb.png.4cebd4f21781638e30bb2b5558f71a0f.png

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2022 was very kind to me not withstanding the many LS cycles where my grid tied stands idle. If there was less LS 2022 could have easily been 20-30% higher than the previous 3 years. It is still the best of the last 4 years.

I show it in kWh per kw installed per day as my panels have increased every year over this period.

pv-years.jpg.554aa60f44f24e9c65fe19b67dd3d928.jpg

Edited by Scorp007
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Hi All

2021 - 70mm 550kwh

2022 - 100mm 656kwh

I think 2021 was low the reason being I finish build my 15kwh bank after the 16th Dec 2021. Would love to have more battery capacity to store more energy maybe in 2023 , system drops down to 1kwh after 11:30am as charge is set at 100amps

Screenshot_20230102_191252_Chrome.jpg

Edited by Raj35
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ahem...

2021 - December rain 48.75mm & 871.8kWh

2022 - December rain 37.5mm & 871.6kWh

fancy that, 19 * 280kWp panels and pretty much identical power produced... actually only 18 * 280kWp panels at the moment/since November, previously 8S + 9S on 2 MPPTs, current 8S2P on one MPPT...

...and these wombats talking about La Nina and el Nino should go back to school and attempt to get an education... the biggest driver of weather on earth is that shiny star referred to as Sol or the Sun and normal for us here on the ar*e end of Africa is that the 1st 3 years of a new solar cycle are above average wet in the summer rainfall regions... this is the 3d rainy season since the start of Solar cycle #25 (the current one) and this one should still give us above average wet conditions, from September 2023 onwards it should be somewhat less damp on average...

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My observation if we compare Dec 2021 with Dec 2022 is that 2021/2022 we has lots of clouds for the greater part of the day with no rain. 2022/2023 we get some nice clouds rolling in followed by rain and then less clouds and sunshine again. Thus we find more rain recorded but also good PV production. Having lots of cloud with little rain was not only in Dec 2021 but for the greater part of summer 2021/2022.

In line with @Antonio de SaAug 2022 was my best ever with little LS and a yield of 5.04 kWh/kW installed per day.

Edited by Scorp007
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10 hours ago, Kalahari Meerkat said:

his is the 3d rainy season since the start of Solar cycle #25 (the current one) and this one should still give us above average wet conditions

good to see that there are others that are also aware of the true drivers of climatic changes.

In recent years, the Sun has been at its weakest state in more than a century. This is revealed by the sunspot count (shown below)–a great barometer for solar activity.


international-sunspot-nu.jpeg?ssl=1 

The Sun’s output ebbs and flows on a roughly 11-year cycle.

As visualized above, the most recent solar cycle (24) finished up closely matching those of ‘The Centennial Minimum’ (≈1880-1914), the previous multi-cycle period of low output, aka a ‘Grand Solar Minimum’ (GSM).

Grand Solar Minimums themselves can also range in depth and length, and, crucially for all of Earth’s inhabitants, these factors determine the severity of the accompanying ‘global cooling’.

The Centennial Minimum was a relatively modest GSM.

https://sidc.be/silso/

 

 

Edited by zsde
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Happy new year and welcome back folks!

While the rain was one thing, the intensification of load shedding is slowly wrecking my batteries... Since I'm in a complex I am not allowed panels as per the governing body for the property. So my batteries were made to work this season, I spent days without power and there was often so little time between outages that the batteries barely got a chance to charge (The biggest issue with any grid tied system that needs AC to charge). So while my KwH produced is at an all time high my batteries are at an all time low, they seem to be maxing out at about 25,7V now instead of the expected +-27V. So starting the year off on a good note this side 🤣 

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7 hours ago, wolfandy said:

Only installed weather station this week, so no rain data yet

I'm really interested in PV generation. All my waffling about rain was to make the point that maybe conditions had been overcast. My first December with my system was the most productive, since then it's dropped off each year.

Now, this might be something I'm doing, or it may be that this has not been a good month for PV.

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23 minutes ago, Bobster. said:

I'm really interested in PV generation. All my waffling about rain was to make the point that maybe conditions had been overcast. My first December with my system was the most productive, since then it's dropped off each year.

Now, this might be something I'm doing, or it may be that this has not been a good month for PV.

Could some of your loss be due to panel deterioration?

Edited by Piper
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5 minutes ago, Piper said:

Could some of your loss be due to panel degradation or deterioration?

Well maybe. I don't know. I know all parts of the system will eventually deteriorate, but I don't know how deteriation is typical. The system was installed in July 2019, so how much would the panels have degraded in that time? 

Also I do recall (even with my memory, it was only last month after all) a lot of overcast days.

So if lots of folks in my neck of the woods are noticing lower PV then it's likely that the sun didn't shine so much. If the results are more mixed then I do need to look at my system. I don't see any tailing off in performance on mornings like this one where the sun is shining brightly in a clear sky.

Edited by Bobster.
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Then it’s probably the overcast causing it. 
I know my production is down to the fact that I’m more conservative with my battery settings due to the stage 5,6 load shedding. Not draining them as low at night because there won’t be AC available if needed. Bit of juggling activity going. 

Edited by Piper
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3 minutes ago, Piper said:

Then it’s probably the overcast causing it. 
I know my production is down to the fact that I’m more conservative with my battery settings due to the stage 5,6 load shedding. Not draining them as low at night because there won’t be AC available if needed. Bit of juggling activity going. 

I haven't changed the DOD on my batteries, but again I can think of other things I've been doing that may have affected PV. But if it's a general thing then it's a general thing.

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Ok well, to expand on production

12/2020 - Monthly Production: 917.1kWh
12/2021 - Monthly Production: 871.8kWh so down by 46kWh
12/2022 - with 1 less panel and a different Inverter 871.6kWh

no data prior to 20th September 2020 and 9th of September 2022 swapped inverters so no data until last week of November 2022 for the current inverter...

Partial data for 2020 and 2022, 2021 was mostly complete, I think....

2021 autumn was fairly poor mostly May, actually, expecting another poor autumn ahead...

Screenshot 2023-01-03 at 09.29.30.png

Screenshot 2023-01-03 at 09.29.07.png

Screenshot 2023-01-03 at 09.28.53.png

 

Oops, looks like May last year was not as bad as I stated, we actually had no internet, mosty due to Eksdom outages in the area...
 

Screenshot 2023-01-03 at 09.56.42.png

Edited by Kalahari Meerkat
more info...
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Panel degradation is highest in the first year. https://solarpowergenie.com/how-much-do-solar-panels-degrade-each-year/

Windy.com provides a SolarPower forecast overview with animation for the next 10 days. Now all this data is obviously available as historic data but the companies that keep that data want some money for it.
You could record the solar power daily info and create your own dataset, that way in the future you could look back at your own historic data and do comparisons with the actuals achieved.

image.thumb.png.43fee5f43c5013fd03432d3c53fccaa9.png

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I am in Hillcrest which is close to Durban.We are about 30 km inland but at 2200 ft above sea level. With the warm humid air coming off the ocean ,it cools and condenses and combined with weeks and weeks of very overcast conditions ,I really had to manage my system well.From an output view it was super  kak but today we have sun.

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Another source of solar forecast and actuals is https://toolkit.solcast.com.au/
Once again, the data is limited to 3 days into the future and actuals for 3 days into the past for the free service. You want more data, get a paid subscription.
I am not sure what their grid size is in terms of the solar irradiation but I don't expect it to be less than 5 or 10km squares.
So low cloud movements and local shading will never be reflected.
The data is based on your site data that you enter once you set up your site. Data intervals are every 30mins.
If you then take a snapshot everyday for the actuals of the previous days, then that can be kept to refer back for comparison with your solar system data.

image.png.0d00325e0601e1c32e9fe982d97d6ada.png

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5 hours ago, Antonio de Sa said:

I've been comparing our two systems on PVOut, you beat me most of the time.

image.thumb.png.07e94614952375f5e9c5cad118a7a46e.png

Thanks for all your figures. I was getting worried seeing more guys with high production in winter. Yes my panels are working flat out and not affected by load or battery but yes LS is a killer but ever so my Dec was the best in 4 years. 

Interesting to see your efficiency as it makes comparing with my system easy do to my adding of panels over 3y 9m 

@Bobster.

I think there are other factors eg the weather affecting your system. The drop from the panels would be so small that you can hardly detect it. 

Guys we better enjoy the period of global cooling as per an earlier post. Pretoria did not experience over 30 degrees C on a regular basis as we are seeing for a few years now. Not sure of global cooling :)

Edited by Scorp007
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