Recommended Panel Size by Location

[Dilbertic]

Hi All,

I was talking to a Solar installer about installing 300w panels and he asked my why 300w? Hmmm OK I said I don't understand.. He said Here in San Jose, CA the Recommended panel size based on sun output is 255w and that 300w panels would be a waste of money..

So I tried to research this, but don't seem to be finding anything based on location by Recommended panel size.. Any truth to this and if so please point me towards some info

Thanks,

Dilbertic

[Naptown]

find another installer this one knows nothing and I suspect him to be a sales type.

[Ian S]

find another installer this one knows nothing and I suspect him to be a sales type.

I suspect he's got a bunch of 255 W panels that he's anxious to unload. The only way what this guy said could make any sense is if he was talking about using Enphase inverters which are limited to lower panel wattage. But that really is not because of solar output per se.

[Naptown]

I suspect he's got a bunch of 255 W panels that he's anxious to unload. The only way what this guy said could make any sense is if he was talking about using Enphase inverters which are limited to lower panel wattage. But that really is not because of solar output per se.

that very may well be.

[Dilbertic]

Thank You All for the feedback.. I thought it sounded a little fishy and Yes he was trying to push a 255w solarworld panels using Enphase Micro Inverters, nothing wrong with them of course, I just wanted a high watt panel using SolarEdge Micro Inverters

OK back to pricing out systems then

Dilbertic

[Ian S]

Thank You All for the feedback.. I thought it sounded a little fishy and Yes he was trying to push a 255w solarworld panels using Enphase Micro Inverters, nothing wrong with them of course, I just wanted a high watt panel using SolarEdge Micro Inverters

OK back to pricing out systems then

Dilbertic

OK, that makes some sense at least regarding the Enphase inverters. 255 W panels would at the upper limit wattage-wise for those inverters especially for a sunny location where you might occasionally achieve nameplate wattage so that may be what the installer was trying to get across.

That said, there is typically no great reason to go for a higher wattage panel: most achieve the higher wattage because they are larger physically. A few (e.g. SunPower) achieve it through higher efficiency as well. But unless you are limited in rooftop real estate for your system, a higher efficiency may not translate into a more cost-effective system. That's why it's most important to look at your installed cost per watt regardless of the power of the individual panel. Now there may also be some advantage for a high power panel like SunPower in that its power decline over the years is supposed to be less so, over its lifetime, you may get more generation than the same nameplate wattage of another brand system. However, SunPower panels typical sell for a premium price. Hope that helps.

[Dilbertic]

RE

OK, that makes some sense at least regarding the Enphase inverters. 255 W panels would at the upper limit wattage-wise for those inverters especially for a sunny location where you might occasionally achieve nameplate wattage so that may be what the installer was trying to get across.

That said, there is typically no great reason to go for a higher wattage panel: most achieve the higher wattage because they are larger physically. A few (e.g. SunPower) achieve it through higher efficiency as well. But unless you are limited in rooftop real estate for your system, a higher efficiency may not translate into a more cost-effective system. That's why it's most important to look at your installed cost per watt regardless of the power of the individual panel. Now there may also be some advantage for a high power panel like SunPower in that its power decline over the years is supposed to be less so, over its lifetime, you may get more generation than the same nameplate wattage of another brand system. However, SunPower panels typical sell for a premium price. Hope that helps.

Hi, Thanks for the great information and that's kinda what I was looking for so I will have to see what the panel size difference is vs Smaller panel and cost per watt. I researched the Solaredge micro inverters and I like the unit and system design and cost. Last time I talked to a local installer he was talking about 1.25 a watt, so I thought about just putting up a smaller system with a larger inverter tie from Solaredge for a 6kw system, the cost is only a few hundred and then add more panels later once I get an idea how the small panels are doing. I have tons of roof, but I was just thinking the 295 to 305 panels don't seem to cost that much more and 20ea 300w panels vs 24 250w panels ends up costing more in costs by 4 inverters, rails and mounts so on..

Thanks,

Dilbertic