I'd have to dig back through bills and it was a different provider too.
I will if I get a chance!
Found it...
2019 period:
Bought 535 day & 692 night
2020 period (solar installed midway):
Bought 462 day & 472 night
Generated 572kWh, exported 147kWh
2021 period:
Bought 69 day & 199 night
Generated 1237kWh, exported 170kWh
August
Total: 792.20kWh
Highest day: 40.062kWh , 7th
Lowest day: 8.031kWh, 20th.
6.8kW setup, South facing. South East.
Decent month for month. Already September is terrible!
Total: 602kWh
Highest: 32.3kWh , Aug 11th
Lowest: 5.1kWh, Aug 14th.
5.7kwp SSW, Galway.
Another really bizarre month, where we didn't break 38C. This means that compared to last year, demand was less (though there were a couple of days where the aircon broke and was constant) and equally solar generation was obscured by cloud. Compared to last year, though, the amount taken from the grid was much better. (Solar install was late March).
Overall, the figures for the 11.5kWh system were as follows, which was rather disappointing.
When installed, the calculations were that somewhere between 65-70% of the summer electricity needs would be met by solar, the actual figure for this month was 56%. Max daily production in the summer is 10% less than it was in spring on a (rare) cloudless day, even though the day is a bit longer. As near as I can tell, it's because the sun is so close to directly overhead that it does not hit the panels as at good an angle, peak production was 7.8kWh, giving 68% efficiency. In winter, the sun is at a lower angle and hits the panels more directly.
Maybe the temperature could be playing a part here too? Typically panels have a best operating temperature of about 25C. Course with them being generally painted black even if the day's air temperature is 38C, your panel might be at 60C (more?) in direct sunlight. Some installs even have little coolers to keep them chilled. Definitely don't spray the garden hose on them anyway as you might crack the glass :-)
I saw somewhere that 0.5% drop off in efficiency for every 1C above the optimal temp for your panel. Different panels will have different optimal temps, but I guess they'll all be around that 25C-30 range.
Your right that the angle of incidence will matter, but August had the same inclination of the sun as would late April/early may, so maybe not angle then?
Did a bit of digging for you.
How Temperature Affects Solar Panel Efficiency (renvu.com)
Well that was a pretty gloomy month
Midlands
4.1kWp SW, 3.3kWp NE
522kW imported
376kWh Generated
328kWh consumed
213kWh to Eddi
0kWh to Zappi
Highest was 7th, 25.7kWh
Lowest was 5th, 5.3kWh
39% self sufficient for month
Monthly cash saving based on average daily load and all non-load items like dishwasher/washing machine/immersion at night rate, €47.57
2.08 kWp, south facing, Cork
150 kWh generated, only 109 kWh consumed, that's both with an E.V and diverter.
April has been the best month of year for me with 274 kWh generated
SE Wexford 6.2Kw, 10.5 Kw battery
Sep Total 499.1kw
Best day 7th 30.5Kw
Worst day 8th 6Kw
Imported 22.9kw (started charging the battery on night rate)
Consumed 435.3kw
Exported 91.5kw
Total Generation since June 2019 13.61MWh
First full month. 2.6kwp facing SSE, Dublin.
Generated 217k
Consumed 163k
Exported 54k
Imported 456k
Zappi 93k
Best 29th - 13.6kwh
Worst 30th - 2kwh
Dismal month, 2.5 kwp south facing Galway.
Total was 191.3kwh.
Best day was 23rd at 14.1kwh.
worst day was today at just 1kwh.
Total since install on 11th May is now 1,380 kwh.
On 16 days I did not exceed 5.5kwh and the average for those 16 days was approx 3.6 kwh per day.😮
S Dublin 7Kwp, 5 Kwh battery
Total 484kw
Best 7th 32.6Kw
Worst 12th 6.4Kw
Imported 113kw
Consumed 552kw
Exported 57kw
EV 91.2kw
Self use 88%
Solar - Grid use 80% - 20%
Total Gen since May 2021 - 3761kw
4.8kW EW Dublin. 2.4kWh battery
September 2021(kWh):
Production: 446.5 (462 predicted)
Consumption: 788
Import: 461 (157d, 304n)
Export: 25.9 (92.6 pred.)
Best day: 6th: 19.3
Worst day:30th: 4.3
September
Total: 391kWh
Highest: 28.7kWh , Sep 23rd
Lowest: 4.2kWh, Sep 18th.
5.7kwp SSW, Galway
September Stats
6.4kWp (4.5 SSE, 1.9 WSW) , 4.8kWh battery, Eddi, dumb electric car charger – Tipperary
Generation – 380 kWh Export – 39 kWh Divert – 94 kWh Import – 201 kWh Best day - 7th, 29.3 kWh Worst day - 13th, 2 kWh
Totals so far:
Month |Generate (KWh)|Export (KWh) |Divert (KWh) |Import (KWh) ---------+--------------+-------------+-------------+------------ November | 163 | -- | -- | 443 December | 117 | 1 | 22 | 552 January | 163 | 2 | 29 | 709 February | 213 | 10 | 47 | 496 March | 436 | 26 | 119 | 384 April | 705 | 54 | 219 | 207 May | 734 | 63 | 223 | 141 June | 722 | 54 | 230 | 104 July | 720 | 177 | 220 | 111 August | 613 | 127 | 184 | 58 September| 380 | 39 | 94 | 201 ---------+--------------+-------------+-------------+------------ Total | 4987 | 552 | 1387 | 4006
September was a shocker - way down on what was forecast.
It was, but Dublin seems not as gloomy as elsewhere based on stats posted
4kw SE/NW. South Dublin. Sept Gen. 212kw. Best 12.9/ Worst 3.2.
3.24kw facing west.
214.7 kwh this month.
Best 14.3
Worst 2.4(today)
705.1kwh since installing in mid July.
Location kerry
4.83kWp system facing south. Dublin.
System only commissioned on the 10th Sept, but 288kWh for month of Sept since installation.
2.52kWp south facing, Dublin city, installed Dec 12th 2020.
December total 58.4kWh
January total 82.6kWh
February total 148.3kWh
March total 222.8kWh
April total 327.2kWh
May total 345.6kWh
June total 341.1kWh
July total 334.2kWh
August total 254.6kWh
September total 214.9kWh
Back down to March levels already, the declining output is causing me a mild dose of SADS!
Highest - September 7th (12.8kWh)
Lowest - September 12th (2.8kWh)
Highest Ever - July 19th (16.6kWh)
200kWh for the month of Sept, only 5.5kWh exported
4kWp SSW facing in North Tipp
6.2kWp (2.8 south/3.4 west), 20kWh battery, Zappi & Eddi – Donegal
Generation – 347.6kWh (down 20% from last year! )
Export – 3.4kWh (down 94.3%)
Import – 316.2kWh (up 54.6%)
Best day - 1st, 26.1kWh
Worst day - 23rd, 2.6kWh
Awful month. 20% drop in generation since last year. Plus I charged the car a lot more this time than September last year so a big jump in purchase. However much of that purchase has been via overnight charging so I don't expect a bump in the bill.
Went live with my system the same day as you so not a full month and I have a 6.1 kWp system. Its saying I generated 347 kWh. South facing, south of Cork City
I have a 6.1 kWp system and only went live on the 10th September so only 2/3rds of the month but I generated the same as you 347 kWh.....(just to rub salt in your wounds 😎) Based just south of Cork City.
I am pretty happy with set up and looking forward to trying to maximize the use out if
4.83/6.1*347 = 274.75kWh
So proportionally, my system performed better. 😋
September 324 kWh
Best day 23rd 23 kWh
Worst day 08th and 12th 4 kWh
Total since install 2.68 MWh
Significant drop in production output this month
8.64kWp on a 6kw inverter,
12 degree roof, NE/SW 50:50
10kwh Battery storage
"September
Generation : 511.3kWh
Solar Used Directly : 174.8kWh - €35.43
Solar Used Nightrate : 15.2kWh - €0.89
Battery Charged : 198kWh
Battery Discharged Day : 137.6kWh - €32.33
Battery Discharge Night : 21.9kWh - €1.28
EVSE Divert : 5.8kWh - €0.34
Battery Discharged From Grid Charging : 22.3kWh - €2.91
Export : 117.5kWh
Total Savings : €72.29"
Month | 2020 | 2021
January | 75kWh | 56.14kWh
February | 121.55kWh | 142.04kWh
March | 200.59kWh | 269.23kWh
April | 279.11kWh | 373.69kWh
May | 396.34kWh | 430.96kWh
June | 264.13kWh | 425.00kWh
July | 261.88kWh | 387.40kWh
August | 254.10kWh | 264.41kWh
September | 268.62kWh | 248.31kWh
October | 151.43kWh |
November | 90.4kWh |
December | 56.47kWh |
Total | 2.41mWh | 2.59mWh
August Generated - 248.31kWh / Consumed - 230.82kWh / Imported - 46.25kWh / Exported - 20.41kw / Eddi - 22kw / Zappi 3kw
Meter Readings 03813 (00886 Day - up 29 / 02927 Night - up 40)
September 2021
5.4kwp east west split
286kwh produced
![Photo of [Deleted User]](https://w1.vanillicon.com/v2/11f397efbb618f280f346771bb290fe0.svg)
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