Solar panels - how much electricity are your panels actually generating?

lisyloo

Mines 3500 - 4400 for 3.9 system

Martyn1981

apennysaved_4 said:

Thanks everyone for the comments. I'm finding this thread very useful.

Quick question though - on the thread 'Talking 'bout My Generation' (great name), people report generating in Os. Could someone tell me what this is please?

As others have said it's based on the industry standard of kWh/kWp, so it standardises our generation, and thus allows us to compare how we've done each day, month, year etc compared to others with differing orientations, locations and even weather on a given day.

But be warned, don't use "O's" outside of MSE, as it's a very old in-joke (possibly 10yrs), and a tribute to Oscargrouch who first suggested we use kWh/kWp to aid in comparisons, but we quickly got bored of typing it all out, and just went for O's (Oscars).

No, it's not you, it is daft, but it shows a fun side and a little bit of MSE community spirit.

jimjames

We have 14 x 215W panels so total of 3kWp. Over the last 10 years (to the day!) we've generated 32528 kWh of electricity so 3250 kWh per year on average. Our panels are almost directly south facing with no shading until late afternoon in autumn/winter and none in summer. From previous posts here it seems like ours are pretty much approaching the maximum you can generate in the UK.

It might not be obvious to someone new to solar but generation isn't linear or simply on/off, it follows a bell curve on a good day. So maximum output is in the middle of the day and tails off at both ends (blue line). On a mixed cloud/sunny day it's much more up and down (purple line) so as well as generating less it will also be much more peak and trough. Much easier to plan to use the electricity on a day like the blue than the purple.

JKenH

PV generation will be much better in summer than winter. My 7.8kw system is predicted by PVGIS to generate an average of 28kWh per day in May but only 3.73kWh per day in December. Total generation per annum is predicted at 6000kWh. My system is split over two roofs, one facing ENE and the other WSW. Consequently I only get around 77% of what a south facing system might generate, the biggest difference being in winter. 

apennysaved_4

I've been asking for quotations for a system. Does anyone know if there's a thread that compares quotes? If not, I'm happy to share here...

CKhalvashi

apennysaved_4 said:

I've been asking for quotations for a system. Does anyone know if there's a thread that compares quotes? If not, I'm happy to share here...

If you can't find one, it may be worth starting one, as many (including myself) are considering such a system at the moment but haven't got round to it.

Remember to include region (NUTS1 should be ok for this purpose as a guide), kW generation and break down any extras (such as storage batteries) if possible.

apennysaved_4

CKhalvashi said:

apennysaved_4 said:

I've been asking for quotations for a system. Does anyone know if there's a thread that compares quotes? If not, I'm happy to share here...

If you can't find one, it may be worth starting one, as many (including myself) are considering such a system at the moment but haven't got round to it.

Remember to include region (NUTS1 should be ok for this purpose as a guide), kW generation and break down any extras (such as storage batteries) if possible.

Done. Here's the link:

https://forums.moneysavingexpert.com/discussion/6314328/solar-panel-quotations-are-they-any-good/p1?new=1

Magnitio

apennysaved_4 said:

My motivation is not really to save huge sums of money in the short / medium term. I've reached the time of life that I have some financial security and want to invest in something like this to do my bit to reduce emissions. I expect to be in this house for the next 10 years at least. I got rid of my petrol car and now lease an EV, so the next logically step is to start generating (and storing) my own electricity. And then get an air source heat pump, but that's another story...

The question is to see if they actually generate the electricity that is claimed. I don't want to spend £000 and then not be able to light a bulb! The next question will be 'what deliver the best kwh for the buck?'

I'm in a similar position having recently retired. I have chosen to invest in a 6.4kwp REC panel installation with 8.2kw battery. I was quoted for cheaper panels, but was looking for a quality system with lower emissions during manufacture. I know that this will generate more than I will use during several months of the year, but it is not all about the finances, it is also about reducing our co2 output. Based on our current energy consumption, payback is expected in 12-13 years (11-12 years with cheaper panels), but I am expecting to purchase an EV at some stage, so will be making greater use of what we generate.

jimjames

Magnitio said:

apennysaved_4 said:

My motivation is not really to save huge sums of money in the short / medium term. I've reached the time of life that I have some financial security and want to invest in something like this to do my bit to reduce emissions. I expect to be in this house for the next 10 years at least. I got rid of my petrol car and now lease an EV, so the next logically step is to start generating (and storing) my own electricity. And then get an air source heat pump, but that's another story...

The question is to see if they actually generate the electricity that is claimed. I don't want to spend £000 and then not be able to light a bulb! The next question will be 'what deliver the best kwh for the buck?'

 I know that this will generate more than I will use during several months of the year, but it is not all about the finances, it is also about reducing our co2 output. 

The advantage is that over the autumn/winter months you may well be able to use all you generate. Our system is 3kWp and on winter days when output is low we have much higher consumption than they produce as our base load is above it. You'd have the advantage that you might be able to use 100% over some months of the year.

Spies

Equally the argument for oversizing is that on those dull days, you'll get more useful generation.