6Kw going in soon in Aliso Viejo

[Alisobob]

I'm trying to decipher that now.... My generation is split between Off peak, and On peak hours. I need to go back, and separate it ...day by day.

[J.P.M.]

Heres my first TOU-D-T statement, and how it all shook out. I also included 3 snapshots , Total use, Peak, and Off Peak.

Hope it sheds some light on how you can save money, combining solar generation, with TOU billing.

[ATTACH=CONFIG]6331[/ATTACH][ATTACH=CONFIG]6328[/ATTACH][ATTACH=CONFIG]6329[/ATTACH][ATTACH=CONFIG]6330[/ATTACH]

Any idea what the bill would have been if you were still on tiered rates ?

[Alisobob]

Heres my first TOU-D-T statement, and how it all shook out. I also included 3 snapshots , Total use, Peak, and Off Peak.

Hope it sheds some light on how you can save money, combining solar generation, with TOU billing.

solar75.JPGsolar72.JPGsolar73.JPGsolar74.JPG

[J.P.M.]

You have panel level data, right? Check and see what the individual panels were putting out at that time. It kind of looks like some panels were clipping and maybe some not, going to M250's might have helped round it out. The amount of energy getting shaved off there is very low.

It might be clipping but from my experience that admittedly suspicious looking plateau isn't that unusual.

Same date, 04/09/2015, my array put out about 8,036 Wh between 12:09 P.D.T. and 13:54 P.D.T. Max. RATE was 4,590 W. MIN. rate was 4,470 W. Fouling at this time is running around 5 % or so.

The P.O.A. irradiance for the same period as estimated from recorded global horizontal irradiance at the array varied between 954 W/m^2 to 982 W/m^2 corrected for pyranometer temp.. Max. P.O.A. occurred at 12:59 P.D.T.

Under a clear sky, things don't change much for about an hour or so on either side of min. incidence angle, which for me occurred at about 13:10 P.D.T. Output usually rolls off a bit sooner in the afternoon which I believe MAY be due to the gradual increase in the temp. of the roof tiles under the array (thermal "lag" of the concrete tiles being the culprit here) which would tend to decrease the radiant heat loss from the underside of the panels, resulting in a slight but I believe noticeable decrease in system efficiency.

So, the plateau on Bob's graph, while it could be due to clipping, may have other, or additional causes. Sometimes things may not be as simple as they appear.

[thejq]

http://enphase.com/global/files/Enph...ightsizing.pdf

Enphase first rated M215 support up to 260W panel, but in 2014, they raise up to 270W.

And back then M250 was rated at up to 300W DC input. http://pdf.wholesalesolar.com/invert...146.1426919041 Now it's 310W.

My guess is that they don't want to lose certain part of the market as panel output keeps increasing, but they don't have the next generation of inverter yet to support them. I can bet that if and when they finally have it, those numbers will come down (or de-emphasized), so they can sell the newer models at higher price/margin.

[Alisobob]

http://enphase.com/global/files/Enph...ightsizing.pdf

Enphase first rated M215 support up to 260W panel, but in 2014, they raise up to 270W.

Thankyou! I have seen the first page of this report, but never saw the whole thing.

Very interesting.....

[sensij]

[ATTACH=CONFIG]6307[/ATTACH]

This is two hour period I'm concerned about.

Would the M-250's have eliminated this plateau ???

You have panel level data, right? Check and see what the individual panels were putting out at that time. It kind of looks like some panels were clipping and maybe some not, going to M250's might have helped round it out. The amount of energy getting shaved off there is very low.

[silversaver]

[ATTACH=CONFIG]6307[/ATTACH]

This is two hour period I'm concerned about.

Would the M-250's have eliminated this plateau ???

http://enphase.com/global/files/Enphase_White_Paper_Module_Rightsizing.pdf

Enphase first rated M215 support up to 260W panel, but in 2014, they raise up to 270W.

[Alisobob]

solar71.JPG

This is two hour period I'm concerned about.

Would the M-250's have eliminated this plateau ???

[J.P.M.]

Thanks JPM.

I'm just trying to play the devils advocate for anyone undecided on which Enphase Microinverter to choose.

You only get one chance to make the right decision.... more info helps you to do so.

You're welcome. And, IMO, you're not clipping much, if at all.

[Alisobob]

Thanks JPM.

I'm just trying to play the devils advocate for anyone undecided on which Enphase Microinverter to choose.

You only get one chance to make the right decision.... more info helps you to do so.

[J.P.M.]

[ATTACH=CONFIG]6304[/ATTACH]

So.. I'm pondering things... and this occurs to me. The max continuous output of my Enphase M-215 microinverters is 215 watts A/C.

I have 24 of them, so max output of the system is 5160 watts.

My nameplate size is 6480 watts D/C ( 270 watt panels x 24)

Question? Is the limiting factor of the microinverters, limiting my system efficiency to 80% ?

I am gaining KW's produced per day, due to longer days, and better sun angle. My peak power produced on the Enphase website is 5.35 KW's.

I shouldnt expect to see this number climb much , due to the limited inverter output, correct?

The Enphase M250 inverter, would bring my maximum continuous power up to 6000 watts, a system efficiency of 92% at peak output, a 12% improvement.

Perhaps that's the way I should have gone?

Bob: Anecdotal stuff:

Your system size is 1.24 times mine.

Our solar climates are somewhat similar. You're probably a bit cooler amb. temp. wise.

On clear days, when you report your output, it's come to my notice that your output is consistently (and a bit surprising to me) close to 1.25 times my output - i.e, giving consistently very similar output per installed kW.

Parenthetically, this is in spite of the fact that my array is Sunpower and, in theory has an arguably better orientation - 195 az, 18 deg. tilt - more eveidence to my and a lot of other contention that equal arrays will produce about equal output, Sunpower and most everyone else.

Back to purposes for this conversation, my array has a 5kW string inverter, and based on a lot of observations, I'm pretty sure it does not clip. Therefore, I'd guess, based on my observations of the similarity in our outputs/installed kW, yours doesn't either.

[sensij]

Look at the line above. Peak power is 225. It was well known in Enphase's first three generations that they would produce 10 W more than the part number suggested. The M250 was originally going to launch as the M240, before they decided to change it up. The M250 is their first model that doesn't produce higher than the name suggests.

Seriously, this is not news. Look through the forum history, this time of year it is common for people to see clipping and freak out. In a system designed per Enphase's guidelines, the lost energy rarely adds up to much.

[Alisobob]

solar70.JPG

From Enphase.

[sensij]

Max output for the M215's is 225 W, not 215 W. If you run the numbers, you'll see the value of the energy you are missing out on doesn't add up to much. If M250's had been the same price, sure, but typically they are more expensive than the value they would bring to your system.