Thoughts on LG 320 watt panels with enphase 250 micros?

[josefontao]

Will there be too much clipping?

[J.P.M.]

Run PVWatts use the advanced parameters tab and use an AC to DC ratio of 320/250 = 1.28 and look for clipping.

[bayareaemt]

I am getting LG-320 watts panels installed with Enphase s280. My installer mentioned that m250 will have too much of clipping..

[J.P.M.]

I am getting LG-320 watts panels installed with Enphase s280. My installer mentioned that m250 will have too much of clipping..

As suggested, run PVWatts and see for yourself. Do it 2 ways, one way w/ AC - DC ratio of 320/280 = 1.28, the other with AC - DC ratio of the default value of 1.1. Subtract one simulation result from the other for a rough estimate of clipping penalty. I'm no fan of micros for most situations, but clipping may/may not be a problem. Verifying/learning on your own will help clarify for you.

[Plut]

I simulated a 320 panel with a M250 vs a S280 for my location and tilt. The S280 only gets me 2.2 kWh more per PANEL per YEAR. That is only 25 cents worth of electricity per Panel per YEAR. Since the S280 averages about $25 more per inverter I would go with the M250.

Clipping for Enphase micro's is not a bad thing, it does not hurt the inverter in any way. People often think they are under utilizing their panels if they have clipping which is a true statement. But you have to also consider that you are under utilizing your inverters anytime it is not converting at full capacity which is the majority of the day.

For my simulation You would only have clipping for about 2 hours per day at the peak of the sunniest days in the 4 best months for your tilt angle. Total about 75 hours per year of clipping.

[ButchDeal]

I simulated a 320 panel with a M250 vs a S280 for my location and tilt. The S280 only gets me 2.2 kWh more per PANEL per YEAR. That is only 25 cents worth of electricity per Panel per YEAR. Since the S280 averages about $25 more per inverter I would go with the M250.

NOTE that this is your location not the OPs. Clipping would be location specifc as well as the value of the energy clipped.
Generally clipping will be on cold and/or breezy days but can be different for different locations at different azimuths.

There is also more to consider like that the S280 is the new design has slightly better efficiency.
Cost differences would be less than stated as well.

[FDJ]

Tagging on to this discussion with my two similar installation proposals. System 1 is a 24p LG 320 with Enphase S280 cost $26.3K, running PVWatts this system estimate to produce12,001 kWh energy value $1958. System 2 is a 25p is a LG 310 with Enphase M250 cost $25.9k, PVWatts estimates 12,104 kWh with energy value $1975. Do you simply look at the lower cost of system 2 or is there some intrinsic value paying slightly more for newer more efficiency? Thanks.

[ButchDeal]

Tagging on to this discussion with my two similar installation proposals. System 1 is a 24p LG 320 with Enphase S280 cost $26.3K, running PVWatts this system estimate to produce12,001 kWh energy value $1958. System 2 is a 25p is a LG 310 with Enphase M250 cost $25.9k, PVWatts estimates 12,104 kWh with energy value $1975. Do you simply look at the lower cost of system 2 or is there some intrinsic value paying slightly more for newer more efficiency? Thanks.

generally you compare them in $/watt
yours are
system 1
7.68kw at $3.42/watt

system 2
7.75kw at $3.34/watt

[J.P.M.]

Tagging on to this discussion with my two similar installation proposals. System 1 is a 24p LG 320 with Enphase S280 cost $26.3K, running PVWatts this system estimate to produce12,001 kWh energy value $1958. System 2 is a 25p is a LG 310 with Enphase M250 cost $25.9k, PVWatts estimates 12,104 kWh with energy value $1975. Do you simply look at the lower cost of system 2 or is there some intrinsic value paying slightly more for newer more efficiency? Thanks.

Did you adjust the AC to DC size ratio (1.14 vs. 1.24) in the PVWatts estimates ? If not, doing so will change the results slightly, but maybe not a lot.

The output estimates of 1.563 kWh/yr. per D.C. kW vs. 1.562 kWh/yr. per D.C. kW seem about equal, the differences trivial, making the efficiency that counts - output/yr. - essentially equal.

The difference in cost/Watt, while probably not enough to worry a lot about for your situation, may reflect differences in "newness". I'd suggest the quality of the panels is the same, with perhaps some of the differences in the panels' slightly different specs from some marketing pressures or some minor adjustments in the mfg. process/Q.C. methods, etc.

I would however, not put a great deal of faith in the PVWatts cost of electricity estimates, especially considering that a lot of tariffs have varying costs based on usage or T.O.U. or both, making differential costs based on average or blended per kWh costs such as for this example, hard to estimate.

[FDJ]

Did you adjust the AC to DC size ratio (1.14 vs. 1.24) in the PVWatts estimates ? .

Yes I did adjust the ratio in PVWatts. Thanks guys for your input that helped me make the decision. I negotiated a lower price on system 1 so I'm going with that.

[kgvenkatesh]

FDJ - you might be leaving money on the table.. unless it's a deliberate choice. For a 7+ kW system such as yours I'd imagine you could get to or better than $3/watt for lg320/Enphase option. I am looking at 4.8kw and hovering close to $3/watt for lg320/solar edge and I know bayareaemt got similar pricing with your exact option. These are from local installers and not national scale players. Saving 40 cents on 7.6kw would be $3000 gross, and $2100 post tax credits. Need to weigh if the installer you picked is worth that premium.

[OftheSeven]

Jose - you changing from your original Suniva setup?

Will there be too much clipping?

[andrewket]

I'm using lg320's with s280's in northern VA and have been clipping for 90-120 minutes each day for the past week. When I was choosing between the 250 vs 280, the price differential was around $20 per inverter. As a percentage of the total cost of the system that's peanuts. I figured buying the latest design which is compatible with the newer envoy and future battery options as well as slightly more effieicent was worth the difference.

[aliris]

As well the older M system seems to have gazillion performance issues reported online. Course with a new product there may not have been time to flush out problems. But I got the sense they redesigned from the ground up to undo a problematic M-series. Were there lawsuits about it?

[aliris]

I would however, not put a great deal of faith in the PVWatts cost of electricity estimates, especially considering that a lot of tariffs have varying costs based on usage or T.O.U. or both, making differential costs based on average or blended per kWh costs such as for this example, hard to estimate.

Well, but these would be comparable between systems, no? So on an absolute basis perhaps not reliable, but comparatively, fine...