String system vs. Optimizer System

[Hkwind1991]

That is pretty good news that utilities are using the bifacial panels to see how they work. Who is using them? I ask because here in Florida I have only seen basic panels arrays set up by POCO's. Since snow is not an issue here maybe the bifacial are not as efficient based on the cost per watt.

Yeah I've mostly seen it in the midwest, but that's partially because the midwest is in my region. I actually just learned how bifacial panels can help with snow mitigation, and it came from questions I had stemming from the recent Texas power issue. I think your theory for Florida makes sense, but I'm not positive. I'll see if I can find out more from some of our other regions. It's likely the company I work for has projects in Florida.

[SunEagle]

Yeah I've mostly seen it in the midwest, but that's partially because the midwest is in my region. I actually just learned how bifacial panels can help with snow mitigation, and it came from questions I had stemming from the recent Texas power issue. I think your theory for Florida makes sense, but I'm not positive. I'll see if I can find out more from some of our other regions. It's likely the company I work for has projects in Florida.

Great. Thanks

[bcroe]

+1 on bifacial panels and snow mitigation. I work on the project development side of utility-scale solar, and these are popular with most developers. If it's good for the utility-scale side, I would tend to believe it also good for the residential side in this case.

The term bifacial implies that the sensitivity is the same on either side, is that
true, or is it some much smaller secondary number? Please explain how a
panel mount can take advantage of bifacial panels, without any shadowing.
What does bifacial have to do with snow mitigation? Bruce Roe

[J.P.M.]

If it's good for the utility-scale side, I would tend to believe it also good for the residential side in this case.

Why ? Different applications.

[SunEagle]

Why ? Different applications.

I agree. For the bifacial panel to work it needs to have the sunlight reflected from below. Unless you have a white roof the reflection is pretty low.

[J.P.M.]

I agree. For the bifacial panel to work it needs to have the sunlight reflected from below. Unless you have a white roof the reflection is pretty low.

And if that rooftop array - like most rooftop residential arrays - is parallel to the roof surface with something less than 15 - 20 cm clearance between panel frames and the roof deck, the irradiance the backside that array sees will be close to zero, making any already hyped up advantage a bifacial panel may have about the same, that is ~~ = zero, even if that array is sitting on a very high albedo roof.

In spite of the hype and innuendo bifacial panel mfgs. push, for most residential rooftop applications, reflected light does not get to the underside of any array that is close to the surface it's mounted on.

Claims of bifacial panels achieving significantly greater energy collection over monofacial panels and studies are mostly B.S. anyway, and especially so with respect to most common residential rooftop applications. Bifacials may have some advantages for some commercial or industrial applications, but even then it's very application dependent and not a slam dunk with respect to cost effectiveness unless the cost differential/panel (not $$/STC W) between the bi and mono panels is very small.

If an application is on a residential roof with a type of orientation we all know about and see all the time - parallel to a roof and a few inches or less away from it - bifacials are a waste of money because there's no irradiance worth measuring that hits the backside of a commonly oriented rooftop array.

[J.P.M.]

The term bifacial implies that the sensitivity is the same on either side, is that
true, or is it some much smaller secondary number? Please explain how a
panel mount can take advantage of bifacial panels, without any shadowing.
What does bifacial have to do with snow mitigation? Bruce Roe

Mostly not true. If it was, which side of the panel saw the sky would not matter.

[SunEagle]

And if that rooftop array - like most rooftop residential arrays - is parallel to the roof surface with something less than 15 - 20 cm clearance between panel frames and the roof deck, the irradiance the backside that array sees will be close to zero, making any already hyped up advantage a bifacial panel may have about the same, that is ~~ = zero, even if that array is sitting on a very high albedo roof.

In spite of the hype and innuendo bifacial panel mfgs. push, for most residential rooftop applications, reflected light does not get to the underside of any array that is close to the surface it's mounted on.

Claims of bifacial panels achieving significantly greater energy collection over monofacial panels and studies are mostly B.S. anyway, and especially so with respect to most common residential rooftop applications. Bifacials may have some advantages for some commercial or industrial applications, but even then it's very application dependent and not a slam dunk with respect to cost effectiveness unless the cost differential/panel (not $$/STC W) between the bi and mono panels is very small.

If an application is on a residential roof with a type of orientation we all know about and see all the time - parallel to a roof and a few inches or less away from it - bifacials are a waste of money because there's no irradiance worth measuring that hits the backside of a commonly oriented rooftop array.

I agree. Unless the roof has a white surface and the panels are tilted due the roof being flat a bifacial panel will not produce anywhere near what would be expected.

[Hkwind1991]

Why ? Different applications.

I was more insinuating that advancements on the utility-scale would lead to better applications on the commercial side. My apologies for any confusion there.

I think your subsequent posts about orientation being the main driver for an advantage of bifacial vs. other models make sense. My understanding of bifacial panels is it's basically like a two-sided panel that would require an amount of reflection on the bottom side to receive the needed energy to heat the other side and melt snow or keep snow from accumulating. I don't know quite as much on the rooftop solar side of solar energy, so I definitely appreciate your insights there.