So now I have a solar PV system how do I make the most of it???

don0301

Doc_N wrote: »

And the pitch of the roof.

and shading, and inverter size (apparently :P)

John_Pierpoint

beansy wrote: »

Hi

New to all this and trying to read up on it through your posts.

We are in N Wales and had our system installed last Sat. To date we are reading 58.5 Kw and had some quite cloudy and dull days last week.

Is this good or ave please?

Thanks

Beansy

15.25 KiloWatthours today a personal best. (ie 1000 Watts for 15 hours or 2000 Watts for 7.5 hours etc.)

Installed 14th February and broke through the 100 kWh target today in S. Essex.
So 58.5 kWh in 8 days sound a fair average performance to me.

Who are you registering with for your FiT payments?

Martyn1981

beansy wrote: »

This is what is says on our quotation sheet:
System output 3.9 Kwp, Panels: 20 Phono Solar panel output 195 watts, SMA Sunny Boy 4000TL
Location: N Wales, Roof: South facing, 30 degree pitch

Hiya Beansy, this may help.

Ran your details through this estimation site

http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php#

It's not as bad as it looks. You can play all you like, but only really need to complete;
Installed peak power - 3.9
Mounting position - building integrated
Slope - 30deg
Azimuth (point of reference, the sun) - 0deg for south
Click on the map for where you live
Click calculate.

I popped in Denbigh, just to get an approx N. Wales location (tempted to put in Llanfairfechan, but concerned that the Essex members might dislocate their tongues!). Results:

Location: 53°11'9" North, 3°25'2" West, Elevation: 86 m a.s.l.,

Solar radiation database used: PVGIS-classic

Nominal power of the PV system: 3.9 kW (crystalline silicon)
Estimated losses due to temperature: 11.4% (using local ambient temperature)
Estimated loss due to angular reflectance effects: 3.1%
Other losses (cables, inverter etc.): 14.0%
Combined PV system losses: 26.2%

Fixed system: inclination=30°, orientation=0°
Month Ed Em Hd Hm
Jan 3.07 95.2 0.99 30.7
Feb 5.52 155 1.80 50.4
Mar 8.02 249 2.70 83.6
Apr 11.80 353 4.09 123
May 14.30 443 5.07 157
Jun 13.50 404 4.85 145
Jul 13.60 423 4.94 153
Aug 11.60 359 4.16 129
Sep 9.50 285 3.32 99.5
Oct 6.26 194 2.12 65.6
Nov 3.65 110 1.19 35.7
Dec 2.19 68.0 0.71 22.0
Yearly average 8.60 261 3.00 91.2
Total for year 3140 1090

The table gets a little distorted, but suggests an annual estimate of 3,140kWh's.

Remember this is only an estimate, and generation will be affected by shading.

Note estimate for Feb 155 units, which is approx 5.5 per day. But don't get too excited yet, weather makes such a huge difference, it'll actually take a few months to see how the system is doing. And really several years to compare good and bad months.

Have fun.

Mart.

Edit: Sorry, meant to say it's looking good so far, congratulations. M.

sly_dog_jonah

Finally a couple of good days of generation again this weekend in cider country! 14.7kWh and 15.0kWh on Sat/Sun respectively, and yet both days had cloudy intervals (as I can tell from SoloPV output graphs).

This has put us back on course to make [PVGIS estimate+25%] (200kWh) for February all being well. Just another 18.9kWh needed by Weds evening. Time for a sun dance. :j:cool:

jackieblack

teachergirl wrote: »

I hate to say it but I think we could do with some rain here in Essex

EricMears wrote: »

You need occasional rainfall else the 'self-cleaning' panels won't self-clean.

jackieblack wrote: »

Absolutely fine with me, it can rain every single night - once the sun has gone down

Well, our panels got a good cleaning last night
Unfortunately it's forecast to be cloudy for the rest of the week now

EricMears

beansy wrote: »

This is what is says on our quotation sheet:
System output 3.9 Kwp, Panels: 20 Phono Solar panel output 195 watts, SMA Sunny Boy 4000TL
Location: N Wales, Roof: South facing, 30 degree pitch

Reasonably comparable to mine.

N Wales is pretty much same latitude as N Derbys & longitude really doesn't matter (sunrise will be a little later for you but so will sunset).

Your 3.9 kwp isn't quite as good as my 4.0 but jolly close.

South facing is ideal - but even a few degrees of error might have some effect. My foundations were pegged out with reference to a shadow cast at true noon rather than relying on a man with a compass ! That wasn't so much optimisation for PV (payback period for solar installations 12 years ago was approx 250 years - yes I do mean two hundred and fifty !) but correct orientation of a house reduces long term heating costs by optimising solar gain.

Your pitch of 30 deg is much better than mine of 17.5. For ideal generation this week, pitch ought to be around 60deg but yours will be spot on for Summer Solstice (& mine will still be a bit too shallow).

Whilst 'orientation' once meant 'alignment (of a church) with compass' it's far more general these days and can certainly include 'pitch'. I don't think anyone would say their sexual orientation was 'East' or 'West' !

FWIW, in the same period that you generated 58kwh, I did 64 but the major factor of difference is local weather. N Wales might well have been more cloudy than N Derbys last week; indeed, on average it will be because your prevailing winds bring clouds straight off the Irish Sea (& Atlantic beyond) but by the time they get to me, same clouds will have dumped rain on Welsh mountains & Peak District. Your only valid comparison is with a similar setup within a few miles of home.

The prediction sites are fine for an annual estimate but a complete waste of time for short term production. Annual cloud cover is reasonably stable but tomorrow's is at best an estimate and next week's virtually impossible to guess.

Kernel_Sanders

EricMears wrote: »

Your pitch of 30 deg is much better than mine of 17.5. For ideal generation this week, pitch ought to be around 60deg but yours will be spot on for Summer Solstice (& mine will still be a bit too shallow).

With the sun rising in the NE and setting in the NW at that time, surely your pitch will be better suited than mine? (Mine is 23°).

EricMears

Kernel_Sanders wrote: »

That's an exceptionally shallow pitch; how did you measure it?

Actually, I've never 'measured' it (perhaps I should ?) - it's taken from the architect's plans and was used as the shallowest possible angle at which Marley 'BoldRoll' tiles can be fixed. That part of the roof is essentially a 'dormer' and we wanted a sloping roof which would shed rain without the leakage problems associated with flat rooves but the shallowest possible pitch to maximise ceiling height in bedrooms without increasing overall ridge height.

If somebody had told me at the time that an insane Government scheme would subsidise PV panels we'd probably have compromised on pitch !


(added later) Just 9.7 kwh but unless KS lives in same village, a direct comparison won't be useful.

Fruit_and_Nut_Case

Kernel_Sanders wrote: »

That's an exceptionally shallow pitch; how did you measure it?

I'll tell you how I measured mine; might be useful for someone without a handy protractor.

I went inside the roof and cut a cardboard template which exactly fitted the angle 'twixt ceiling and floor. Then scanned this in to my PC and used Paint Shop Pro to rotate the image until the ceiling was horizontal. The required rotation indicated the slope of my roof to be 32.5 degrees.

don0301

or download a spirit level app to your phone, and put it against the ceiling.