Yearly PV Generation Thread

My totals for the last 3 calendar years.

My setup is 2.08 kWp South facing, Cork, I should also mention that my roof pitch is about 45 degrees which seems to be a factor on my higher than average production.

2019: 2061 kWh

2020: 2128 kWh

2021: 2113 kWh

Interesting. Do you have temperature telemetry for the inverter? e.g.

Just wondering if your inverter is in the attic and it's getting too warm and then going into "idle mode" or something. Although that wouldn't really explain the "spikes" down. it would tend to be limited more for duration. Still it does seem to happen more in the afternoon from your chart above

Thanks mate - out of curiosity can you define more what you mean by "gird over voltage". Are you saying it's trying to export out to the grid at over tolerance. i.e. the 230 +/- 10%, so it would be greater than 253V, as a result it shuts off? Is that what you mean?

DrPhil's stats

6.2kWp (2.8 south/3.4 west), 20kWh battery, Zappi & Eddi – Donegal

Aug to Dec 2020 - 1.46mWh

Full 2021 - 4.68mWh

I dont have temperature info with the inverter however it is in the attic. It could likely be the temperature. I will set up temperature collection this year

2021 4.8kW E/W 2.4kWh battery. Charged battery at night rate in winter. EV and Zappi.

Production: 4194.5 kWh (Predicted: 3782)

Highest: 33.5 (May), Lowest 0.4 (Dec)

Total Consumption: 9159.3 kWh (That EV sure bumped up consumption. Used to average 5400 before.)

Export: 595.2 kWh (predicted: 1105.1) (Export almost halved thanks to the EV)

Import: 5560 kWh (2040 Day, 3520 Night)

Savings @ 19.89c/9.85c : ~645 Euro (assuming 700 units used at night rate/car charging) (I didn't pay this rate all of last year but this is the rate now. Probably paid closer to 16.5c on average so actually saved ~536)

For 2022, I have a larger 10.2kWh battery so I expect export of < 100kWh, much more of my usage to shift to the night rate and the Energia EV plan becoming a viable option.

4.65 kWp North Dublin (split SE (2.17kWp) / SW (2.48kWp winter shading) 

5.7 kWh Battery

PV power generation: 4287.70 kWh (Predicted: 4144 kWh)

Feed-in: 1157.60  kWh

Load:       5178.57  kWh

Grid Consumption:   2048.47  kWh 

Charge:             1732.70 kWh

Discharge:          1703.00 kWh

Eddi:               No idea as had power cut and looks like it resets its counters back to zero!!!

Saving:             652.79 euro (594.26 euro PV) (58.63 loadshifting - grid filling battery at night rate)

For 4 months of the year my panels perform worse than https://re.jrc.ec.europa.eu/pvg_tools/en/tools.html stats suggest due to shading from neighbours house and tree got about 50-70% of expected. But on the plus side every other month I was between 94 and 121%. (four months 115-121%)

** Edited to fix missing load line which screwed up some of the other figures!

4.7 E/W split in Cork, no battery. Generated 3.9mw. 1.4mw of that went in to the water tank. 700kw exported. Pretty happy with about 80% self use. A big chunk of the export was when we were out of the house on holidays for 2 weeks during the best weather of the summer

Like a good few others, I passed the yearly installation anniversary there recently (Oct 27th to be exact), but since I only report on full months - it's only now that I have the full 12.

Installation is 5.3Kwp of panels split 1.5Kwp East & 3.8Kwp West (exactly 90/270 by the way), coupled to a GivEnergy 5.4Kw inverter and 8.2Kwhr battery. In sunny Dublin 16 - LOL. Here's the data.

Some thoughts/observations.

With the mining, I'm in a semi unique position that I can scale my load up/down to virtually consume all the units I produce, so for most of the year until late July (when I installed an additional 2.3Kwp on the shed), you can see I exported virtually nothing <10 units month. From August on, the shed added to the generation that meant I was exporting a little more. The above grid doesn't include the shed generated, except indirectly the amount exported from the house as the shed helped cover the house load, so the stats reflect that in the original installation being able to export more as the house loading "reduced" meaning my original installation had more units to divert to the battery/export.

Payback timeline for me (excluding any crypto coins mined) would be 7 years as I paid €8500. If I include the crypto, it's 3.5 years as I mined €1,300 in the 12 months. Mining however with the Ethereum migration to "proof of stake" has meant it's not as profitable as it was. (About 1/5th the value) So that won't continue. But I view my payback timeline as 7 years. You could argue that if I wasn't mining then I'd be using less, so my payback is longer - but then again, I don't count FIT in any of the above (still haven't gotten paid from SSE - and probably wont), so one sort of balances the other. Different people will have different formulas, some including depreciation, or "loss of opportunity costs" on that €8500, and that's fine - and would come out with a longer/short timeline. Rock on. My formula/thinking is 7 years.

For those of you looking at what "real world" yields are, you can note that Mar (421 Units) -> Oct (233 Units), the system produces a very healthy and useful amount of power. Nov (99Kwhr), Dec (58Kwhr), Jan (103Kwhr), Feb (162Kwhr)....while it's something, with an average production of 3-4Kwhr/day it's not going to be doing much - that said, it's a few quid off the bills. The battery here was saving me about €30/month - although I had an issue with my battery for Nov+Dec which was replaced, so that's why it was lower above. Jan was the first "correct" month for battery. The savings of €193 a year with the battery is only the savings generated from grid in at night time. You also have the battery for storing solar energy and using at day rate. So the real savings with a battery for me is about €350-400/year

Technical performance:

Some observations.

Many of us will know this already, but with the poor "slant angle" the East/west split has, it does pretty poorly in winter. You can see that the highest output, even on a sunny day in December was 1409watts off 5.3Kwp. So approx 26% of the max rated power. Conversely in summer I've seen the inverter handle regular spikes to 5600watts, which is the realistic max I would expect. That's not to say E/W is bad, it's not - and if you have this as your roof in some respects it's actually the best (debatable) as you get a much longer power curve during the day, rather than a huge spike at noon which sometimes is difficult to manage all the power. For example, with a lower (but longer) generation curve, you can put on the washing for 2 hrs and then the dryer after it. With all the power coming quickly in about noon with a South facing array, it's harder to manage that. Battery of course helps, but if you are producing 5Kw and the battery can only charge at 2.5Kw.....you can see the problem! FIT has changed the landscape a little since I got my installation put in, so what wasn't completely a good strategy before has now become viable, and vice versa.

The production verses the PGVIS results are pretty good. Generally, I beat it by about 15%, with last March being the obvious outlier. (It really was a great month for solar)

Overall thoughts

Pretty happy with the installation. Battery works well for me. I'd buy one again, but it really does depend on your consumption. I've somewhat of a unique ecosystem with the mining and using that for heating is another benefit that I'm not burning fossil fuel (natural gas). Still haven't turned on the heating yet and it's Nov 1st first as I write this - but while the mining allows me to heat from electricity, it's not powerful enough to heat during a right "beast from the east" cold snap. So I'll have to fire up the boiler eventually. :-(

What would I have done differently?

Not much. I am adding 3x panels to the roof shortly, but it wasn't possible to do this originally as I would have violated the 50cm gaps that the SEAI guys want to see or they will deny the grant. With it being my dime, I can drop that down to 30cm and get 3 more panels up there.

Panels panels panels are the key (mostly). You can actually have too many panels, but it's hard. Real hard - to have too many. Max your roof is the single biggest piece of advice anyone can give you, that and stay away from the gougers in the market place.

Man, that last table shows the benefit of solar. Bar winter, you’re only paying 50-100 quid every months on kWhs - and that includes the car charging. And before you deduct FIT. That’s unreal. Ok, you’ve a big South setup which is great. Hats off to you! 

For sure, we're lucky that we can afford it. I constantly count myself lucky that we don't have to worry about energy bills. And, for the 1st time, I notice when my elderly neighbour has her gas boiler running a lot. And I'm thinking that must be costing a lot. Not an easy time for everyone.

Would be amazing to see more of a push from the State on it to somehow make it more available for those on lower incomes. I know some will say it's only €50+ per month for solar as a service, but that's more than some can afford.

Or to even get on public buildings (once the roof suited it of course). I worked in a State org and we leased a brand next 6 floor city centre building for 25 years and weren’t allowed access to the roof (as tenants). So likes of solar is not possible, unless the landlord decides to install themselves (which they won’t when tenant pays for power). The roof is of course the same footprint as the floor - which is large for all new buildings on the Liffey in Dublin. Ok, roofs on commercial buildings tend to have a lot of ducts, masts….but the fact that none of them (that I have ever seen) have solar tells a story.

If there were public buildings plastered in them that the general public could see it might help. There's an education piece for people to see the benefits. It was only when I was getting quotes and reading up that I realised it was light levels not temperatures.

Anyways, off topic but very much linked to the benefits of solar. 

7kwp S facing W Dublin on 6kw inverter

Very happy with 85% self use, 2023 should be a bit higher as I only added 20kwh batteries in April of 2022. Or less as I plan to add another 1kwp shortly.

1400kwh into the PHEV

First full calendar year and produced 7,010 kWh on my 6.1kWp system just south of Cork City

Best Month was August at 925 kWh

Best Day was 28th May at 44.5 kWh

Rough estimate my PV system saved me €940 in PV generated used at day rate. About 43% should be more next year as I only got my EV in July..

I got FIT off Electric Ireland of €320. If I had a smart meter I should have got around €815 from February to December (all before Tax!!)

Out performed most months from the PVGIS estimate apart from JUNE of all months! that month was a disaster.

My aims for next year is to obviously increase my self usage but with the FIT at €21c Im not too concerned. The EV should help matters as I only got it Mid July last year so missed the best of the years production. Plan is to get a smart meter installed ASAP but struggling as I am down the priority list for EI as I have a day/nigh meter already.