SolarEdge POWER Accuracy? 11,900 AC Watts from 12,000 DC array

[gvl]

Understood, posted to show that there can be even more surprising output numbers than in the OP. I think my inverter was clipping too, wondering how high the spikes would be with no clipping.

[J.P.M.]

I saw up to half-minute bursts of 10200 AC watts today from a 9kW DC system on a 10kW inverter.

That's mostly because instantaneous solar radiation peaked at 1,100 to over 1,200 W/m^2 several times today. Nothing unusual for cloudy/pt. cloudy skies. Today's total around here is likely to be about 75% of a clear day's output for this time of year.

[gvl]

I saw up to half-minute bursts of 10200 AC watts today from a 9kW DC system on a 10kW inverter.

[russ]

Let us know if that irradiance stays high for an extended period of time. That might be an indication that the sun is somehow producing a lot more photons than normal. And you know what that means!!

Somebody pulled the control rods too far out?

[SunEagle]

The last few days, the pyranometer next to my array has reported and recorded several periods from 1 min. up to 20 min. when the global horizontal irradiance reached over 1,100 W/m^2, with several of those 1 min. interval reading in succession over 1,200 W/m^2. The highest 1 min. irradiance was 1,267 W/m^2, 30 successive min. at 11:42 to 11:45 P.D.T., 05/18/2015. All high readings were only momentary and are due to reflections and forward scattering of sunlight by clouds. For the last 16 months, the highest clear sky P.O.A irradiance I've calc'd is about 1,030 W/m^2. There may be some ground reflected radiation component in there.

Let us know if that irradiance stays high for an extended period of time. That might be an indication that the sun is somehow producing a lot more photons than normal. And you know what that means!!

[J.P.M.]

Haha, you want to see something really funky? A few days ago I saw 5.32KW AC from my 4.8KW system.

[ATTACH]6748[/ATTACH]

I'm sure it's a combination of cloud edge effect + SE SW glitch. It's no way physically it can happen in any sustainable fashion. So I wouldn't pay too much attention to instantaneous measurements, especially in a partially cloudy day.

The last few days, the pyranometer next to my array has reported and recorded several periods from 1 min. up to 20 min. when the global horizontal irradiance reached over 1,100 W/m^2, with several of those 1 min. interval reading in succession over 1,200 W/m^2. The highest 1 min. irradiance was 1,267 W/m^2, 30 successive min. at 11:42 to 11:45 P.D.T., 05/18/2015. All high readings were only momentary and are due to reflections and forward scattering of sunlight by clouds. For the last 16 months, the highest clear sky P.O.A irradiance I've calc'd is about 1,030 W/m^2. There may be some ground reflected radiation component in there.

[rhedayi]

Yeah clouds rolling by etc, it was instantaneous, spike, barely caught evidence of it5600.jpg

[SunEagle]

On SE web portal (see signature) the "Current Power" changes every few minutes or so. I'm not sure how it is calculated, but it's very erratic in partially cloudy days as the result of edge effects (light reflect and refract off cloud edges, and sometime focuses large amount of light onto a small area, like a magnifying glass) and cool temperature. So maybe for a few seconds or minutes it did reach 5.32KW, but definitely not over a long period of time.

I understand about the cloud affect. It is similar to reflected sun from snow onto a panel which can inflate the KW production numbers.

That is why there is research using concentrated or magnified solar pv panels so more photons can be captured to create a panel with a higher % yield.

[thejq]

Is that 5.32kw a "peak" reading for generation over few seconds or over a longer period of time?

It's like using a meter to measure your kW load where you see a "peak" kW when the AC unit comes on but the actual continuous load is much smaller after the initial start.

On SE web portal (see signature) the "Current Power" changes every few minutes or so. I'm not sure how it is calculated, but it's very erratic in partially cloudy days as the result of edge effects (light reflect and refract off cloud edges, and sometime focuses large amount of light onto a small area, like a magnifying glass) and cool temperature. So maybe for a few seconds or minutes it did reach 5.32KW, but definitely not over a long period of time.

[SunEagle]

Haha, you want to see something really funky? A few days ago I saw 5.32KW AC from my 4.8KW system.

[ATTACH]6748[/ATTACH]

I'm sure it's a combination of cloud edge effect + SE SW glitch. It's no way physically it can happen in any sustainable fashion. So I wouldn't pay too much attention to instantaneous measurements, especially in a partially cloudy day.

Is that 5.32kw a "peak" reading for generation over few seconds or over a longer period of time?

It's like using a meter to measure your kW load where you see a "peak" kW when the AC unit comes on but the actual continuous load is much smaller after the initial start.

[russ]

I wouldn't pay too much attention to instantaneous measurements, especially in a partially cloudy day.

You got it - a meaningless number really.

[thejq]

sunday was funky, at one point my 5.2kw system was reading 5600 !!!

Haha, you want to see something really funky? A few days ago I saw 5.32KW AC from my 4.8KW system.

Capture3.JPG

I'm sure it's a combination of cloud edge effect + SE SW glitch. It's no way physically it can happen in any sustainable fashion. So I wouldn't pay too much attention to instantaneous measurements, especially in a partially cloudy day.

[russ]

sunday was funky, at one point my 5.2kw system was reading 5600 !!!

Some clouds?

[rhedayi]

sunday was funky, at one point my 5.2kw system was reading 5600 !!!

[makarowski]

What was your "Net Delay" set to??

My net delay was 15 min...for fun I changed it back to 0 ..And will see how it looks over the next few days... I will be looking for those false 0 usage data points


Cheers
BMak