Renewables: "talking 'bout my generation"

EricMears

Rheumatoid wrote: »

Why are you located near to me with a similar orientation but with bigger system and lower target?

Possibly you're using different versions of the PVGIS calculator ? There are several different 'models' that you can select and all of them got revised a couple of years ago. It isn't therefore enough to say "my PVGIS forecast is xxxx", you need to explain which model you used and when you last checked the site.

ispookie666

2.4 O's yest at least its producing more O's than just 0's
:T

EricMears

FWIW, I've just had a look at the PVGIS page.

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


I entered Thetford (near enough SW Norfolk) along with 35 deg slope S facing Roof (defaults) to get :-

PVGIS-classic : 878 kWh / kWp / Year
PVGIS-CMSAF (aka: 'climate change') : 962kWh / kWp / Year

both of course are today's forecasts but they would have been different a couple of years ago.

Funnily enough, there's very little difference between the two for the month of February.

That doesn't of course allow for other factors such as one of our Norfolk guys having slight shading or in a valley and the other on a hilltop facing out to sea etc etc

ely_ellis

Not been around much for a few months now, a bit like the sun I suppose!

Pretty poor generation (as probably everyone else), since Oct 2015 not reached PVGIS, but this Feb, blasted through it and not finished yet as today looks like a clear sky!

Month PVGIS Gen Difference
Oct 252 254 +2
Nov 158 123 -35
Dec 126 101 -25
Jan 128 106 -22
Feb 191 282 +91 (and still have today to add)

Looks like this Feb has me covering up for the shortfall since October.
Now then, what to do with all this generation today!

Cheers
Martin

Rheumatoid

EricMears wrote: »

FWIW, I've just had a look at the PVGIS page.

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


I entered Thetford (near enough SW Norfolk) along with 35 deg slope S facing Roof (defaults) to get :-

PVGIS-classic : 878 kWh / kWp / Year
PVGIS-CMSAF (aka: 'climate change') : 962kWh / kWp / Year

both of course are today's forecasts but they would have been different a couple of years ago.

Funnily enough, there's very little difference between the two for the month of February.

That doesn't of course allow for other factors such as one of our Norfolk guys having slight shading or in a valley and the other on a hilltop facing out to sea etc etc

Ahh, maybe he has shading and I don't. 970 O's (SAF Database), 885 (Classic), here but Jan=135kWh, Feb = 200kWh (SAF)

shavy65

Fantastic weekend for me up here in NE Scotland -> a combined 8.2 O`s

Crowmann

EricMears wrote: »

Possibly you're using different versions of the PVGIS calculator ? There are several different 'models' that you can select and all of them got revised a couple of years ago. It isn't therefore enough to say "my PVGIS forecast is xxxx", you need to explain which model you used and when you last checked the site.

I am just going by the contract details for the install - I do have an 'extra' 265w panel so I should really add 6.66% to the months target. which gives me 202 Kw.


Does that sound more like the right number?


Either way today has started well here and assuming it stays that way the system will pass even the revised target by 50%.


Now if it does that for the rest of the year and the iBoost grabs 80% of the surplus as it is currently then the recovery period for the panels will be close to 5 years.

Crowmann

No shading - just clear sky!

Rheumatoid

Crowmann wrote: »

I am just going by the contract details for the install - I do have an 'extra' 265w panel so I should really add 6.66% to the months target. which gives me 202 Kw.


Does that sound more like the right number?


Either way today has started well here and assuming it stays that way the system will pass even the revised target by 50%.


Now if it does that for the rest of the year and the iBoost grabs 80% of the surplus as it is currently then the recovery period for the panels will be close to 5 years.

That probably explains it. My contractors were obliged to give a conservative estimate and it is much lower than PVGIS - whatever version.

What do you get here:

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

Crowmann

On that calculation I get ....


So this month was up but overall doing a few adjustments as the system went live on the 13th Nov but had some outages due to installers and inverter I am down about 30Kw from the start date to the end of Feb.


So good news really?


I guess as the installers guarantee the output or nearly all the output they put a low ball number on the kit?


Nominal power of the PV system: 4.2 kW (crystalline silicon)
Estimated losses due to temperature and low irradiance: 7.5% (using local ambient temperature)
Estimated loss due to angular reflectance effects: 2.9%
Other losses (cables, inverter etc.): 14.0%
Combined PV system losses: 22.8%
Fixed system: inclination=45°, orientation=0° MonthEd Em HdHm Jan 5.121591.4745.7 Feb 8.012242.3465.5 Mar 12.503883.75116 Apr 15.704704.85146 May 15.904945.02155 Jun 15.704715.03151 Jul 15.504804.97154 Aug 13.904304.42137 Sep 13.003914.07122 Oct 9.683002.9391.0 Nov 6.952082.0360.9 Dec 5.051571.4444.7 Yearly average 11.4 348 3.53 107 Total for year 4170 1290