Renewables: "talking 'bout my generation"

ely_ellis

Crowmann wrote: »

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?

Just wondered also if you are taking your generation figures from your inverter or your generation meter.
I know that I cheat a little as I use the figures from my Solaredge monitoring (the inverter figures) which I know are a little higher that my actual figures recorded on the generation meter.
Although not much, but I believe a greater tolerance on the inverter to your generation meter is allowed.
For example, since installation (8 months) my generation meter shows 2194 kWh, but my inverter shows 2270 kWh. Some 76 kWh difference (about 3.4 %).

Of course, this could be nothing to do with it, just thought I would mention this.

Cheers

Martin

Rheumatoid

Crowmann wrote: »

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

That is more in line with mine bearing in mind your slightly larger system :T

Nov/Dec were a right off for most anyway :rotfl:

Crowmann

Just re ran it as I had put 'free standing' when of course it is building integrated.


Reduces the annual number to 3970Kw.


On that basis my newly installed system has performed across three and half months exactly to PVGIS.


Who would have thought?


Fixed system: inclination=45°, orientation=0° MonthEd Em HdHm Jan 4.911521.4745.7 Feb 7.632142.3465.5 Mar 11.903693.75116 Apr 14.804444.85146 May 15.104685.02155 Jun 14.904475.03151 Jul 14.704574.97154 Aug 13.204084.42137 Sep 12.403724.07122 Oct 9.222862.9391.0 Nov 6.662002.0360.9 Dec 4.871511.4444.7 Yearly average 10.9 331 3.53 107 Total for year 3970 1290

Crowmann

ely_ellis wrote: »

Just wondered also if you are taking your generation figures from your inverter or your generation meter.
I know that I cheat a little as I use the figures from my Solaredge monitoring (the inverter figures) which I know are a little higher that my actual figures recorded on the generation meter.
Although not much, but I believe a greater tolerance on the inverter to your generation meter is allowed.
For example, since installation (8 months) my generation meter shows 2194 kWh, but my inverter shows 2270 kWh. Some 76 kWh difference (about 3.4 %).

Of course, this could be nothing to do with it, just thought I would mention this.

Cheers

Martin

I am using the generation meter, not the inverter.

Rheumatoid

Crowmann wrote: »

Just re ran it as I had put 'free standing' when of course it is building integrated.


Reduces the annual number to 3970Kw.


On that basis my newly installed system has performed across three and half months exactly to PVGIS.


Who would have thought?


Fixed system: inclination=45°, orientation=0° MonthEd Em HdHm Jan 4.911521.4745.7 Feb 7.632142.3465.5 Mar 11.903693.75116 Apr 14.804444.85146 May 15.104685.02155 Jun 14.904475.03151 Jul 14.704574.97154 Aug 13.204084.42137 Sep 12.403724.07122 Oct 9.222862.9391.0 Nov 6.662002.0360.9 Dec 4.871511.4444.7 Yearly average 10.9 331 3.53 107 Total for year 3970 1290

I may have made a similar mistake then. If I go for building integrated I am massively outperforming estimates but reading around the 14% loss default does seem high for a modern system.

EricMears

Crowmann wrote: »

Just re ran it as I had put 'free standing' when of course it is building integrated.

Ah, but is it really integrated ? This is what the PGGIS help page has to say about the difference:-

In the application there are two possibilities: free-standing, meaning that the modules are mounted on a rack with air flowing freely behind the modules; and building-integrated, which means that the modules are completely built into the structure of the wall or roof of a building, with no air movement behind the modules. Some types of mounting are in between these two extremes, for instance if the modules are mounted on a roof with curved roof tiles, allowing air to move behind the modules. In such cases, the performance will be somewhere between the results of the two calculations that are possible here.

rodee13

ely_ellis wrote: »

Just wondered also if you are taking your generation figures from your inverter or your generation meter.
I know that I cheat a little as I use the figures from my Solaredge monitoring (the inverter figures) which I know are a little higher that my actual figures recorded on the generation meter.
Although not much, but I believe a greater tolerance on the inverter to your generation meter is allowed.
For example, since installation (8 months) my generation meter shows 2194 kWh, but my inverter shows 2270 kWh. Some 76 kWh difference (about 3.4 %).

Of course, this could be nothing to do with it, just thought I would mention this.

Cheers

Martin

Same for me..my solar edge inverter output shows around 3-4% more than actual generation meter output. I usually check output using pvoutput.org (they got a nice iphone app) which is closer albeit bit higher than gen meter. Today on track for a record day with 13-14kWh for me.

ely_ellis

rodee13 wrote: »

Same for me..my solar edge inverter output shows around 3-4% more than actual generation meter output. I usually check output using pvoutput.org (they got a nice iphone app) which is closer albeit bit higher than gen meter. Today on track for a record day with 13-14kWh for me.

Just been to that pvoutput.org site and found I am already a member!
Must have joined a while ago and never used it probably because it appears to be a manual data entry system unless I am missing something.
You say you check your output using pvoutput.org, how do you do that exactly as from what I can see you enter the data manually and therefore it only gives you a record of what you enter.
Maybe there is more to it and would appreciate more info if there is.

Ta

Martin

rodee13

ely_ellis wrote: »

Just been to that pvoutput.org site and found I am already a member!
Must have joined a while ago and never used it probably because it appears to be a manual data entry system unless I am missing something.
You say you check your output using pvoutput.org, how do you do that exactly as from what I can see you enter the data manually and therefore it only gives you a record of what you enter.
Maybe there is more to it and would appreciate more info if there is.

Ta

Martin

yes it used to be manual some years back but now it can read data from certain inverters automatically. For solaredge you just need to provide siteid and API key (http://pvoutput.org/help.html#autoupload-solaredge)

you can get the API key from installer or by emailing solaredge with your details like siteid etc.

ely_ellis

rodee13 wrote: »

now it can read data from certain inverters automatically. For solaredge you just need to provide siteid and API key .

Thank Rodee, that's useful to know.
I will have a go at that
Cheers
Martin