New Panels-Solar

325 watts? not worth the trouble...

I expect a link to that installation with full costs, and bill of materials on my desk by morning!

I think I could run most some of my shop building with that. Still won't get me any Air Conditioning out there, and no electric heater (other than a large light bulb).

New headline: Texan freezes to death in Blue Norther after wife kicks him out in the shed. LED bulbs do not have much thermal output he learns posthumously.

Led lighting.... that's it.

Two pigeons land on your roof and poop, poof, 175 watts, hmmm, NO!

You'd be amazed at how little that actually affects the panel output.

You can't get that much from burning pigeon poo.

Well, maybe not as is, but with a little refinement, charcoal, and sulfur...

Nice photo. I know that since I started feeding doves in the backyard, we have volunteer radishes, wheat, and God knows what else coming up, but the grass is Ireland green and Boston strong in Lubbock, TX, no less.

There is a lot to be said for a biodiverse yard instead of a monoculture.

My wife loves greenery, and makes every place she lives into a new paradise. I just bring a pair-o-dice.

So, what are the improvements? What makes this novel, noteworthy? Rooftop solar has been available for decades.

Is it the brown color that might match some rooftops?....though in hotter climates, lighter colored rooftops might save a significant amount of energy. I doubt the panels come in white.

Maybe the lack of specular reflection is seen as an improvement?

I guess when prices are posted, a cleared picture will be available.

You are aware, sir, or madam, that in order to produce electricity, firstly, radiation from the sun has to be absorbed? For efficient conversion, the energy needs to have a high quantum yield of charge carriers, and a low rate of charge carrier recombination, or cancellation at type boundaries. Also of importance to efficiency is the reflectivity of re-radiated photons so that these are not efficiently coupled out of the material, but have a high probability of re-absorption. Even further efficiency can be gained by having multiple active layers that absorb different bands of the spectrum.

White just ain't gonna get the job done.

.....which is exactly why I doubt the panels come in white.....so if you have a high reflectivity white roof for energy savings in the summer, any perceived benefits of having the panels blend in is no longer on the table.....however if you have a hot, low reflectivity brown roof that does not benefit efficiency in the summer by keeping attack Temps down, step right up for your matching panels.

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Yes, sir, or madam, I get that reflectivity is not a goal of solar panels...but you have been up close to typical solar panels, right? If so, I'm sure you have moved through the specular reflection of the sun off the glazing. There is a non trivial amount of reflection occurring, wouldn't you agree?

I agree about the specular reflectance, and this is due to off-angle set-up, among other things.

One thing that has been looked at is "moth-eye" surface topography to reduce specular reflection, but my question there is how would they actually manage to keep it clean?

Would high surface static charges to repel dust work?

That seems like an awful lot of panel area just to produce a paltry 325 watts. Note the second set extends beyond right edge of the photo. Can we safely assume the entire panel area produces only that much? And given its brownish colour, this looks to be using amorphous silicon which is considerably less efficient than polycrystalline cells. I see no advantage here.

I would guess that's 325 w per rectangle, so this looks like it could be 8, maybe more (don't know how far to the right they continue), this would be a 2.6kW system.

Shawn

According to this article, it is 325 watts per panel, there is 20 of them on this roof, 6.5kW total.

That seems about right, after all.

The new trick with CSP (this is not CSP), is to use the backside as well.

325 Watts per panel is pretty near industry average. The more telling number is watts per unit area. That will give you panel efficiency. Over the past few years, manufacturers have improved processes & QC to bring their efficiency up, most to around 15-16%.

I haven't checked recently, but Sanyo and Sunpower were the only manufacturers to hit more than 20% efficiency. There are probably more out there now. According to the article linked by JPool, these will reach 21.76%.

When all is said and done, if you've got room to mount less efficient panels that cost less, it'll be more cost effective to use those panels. If you are space constrained, and typically roof top mounts are, then the higher efficiency panels will be more attractive.

Speaking of attractive, looks like they've dressed up the edges of the array to make the system look more attractive. Not something you see very often.

It would be a benefit to make them more aesthetic and fitting in the surrounding. such as tiled, wood shingles or color. Things on that line. I don't know how this would affect efficiency.

One of the problems with camouflaging them too well is in case of fire. A typical string reaches 300-400 volts DC. If there's a fire, they're dousing it with water and potentially attempting to hack through it with an axe, not a situation you want to put a firefighter in.

Even with obvious roof mounts, fire companies tend to be leery of working around them. Rightfully so in my mind.

If there's a fire, they're dousing it with water ....

Thanks,... never thought about that, ...

Nah, let it burn... the materials should recycle just fine.

I did hear of a situation in which a building was lost to fire due to the inability to get through a solar array above the area that was burning. The delay in going through the panels, and the potential of electrical problems on top of the mass involved, resulted in the loss.

Fire codes will probably have to be updated to provide an external disconnect that is accessible from the ground to at least separate the array power from the rest of the dwelling. Understand that you can't turn off an array very well unless you wait for night.

Firefighters vent roofs away from solar panels . Sometimes the vent holes aren't being placed in the best area , but getting zapped is avoided by all costs . Thus solar panels do sometimes slow up venting operations .

I'd prefer them to be recessed so they were flush with the roof. But that would be best done when the house is being built. That way, they would tend to catch less airborne leaves, etc. Plus it wouldn't give it such a noticeable profile.

I, myself would prefer them to be part of the roofing... and unnoticeable.

My preference would be to build a large patio covering with solar panels. That way, when the house burns down, we will still have power! (Insert laughter here).

Once flexible solar panels are being marketed, maybe the awning folks will make a retractable awning of solar panels, so they can be protected from hail. Another issue to surmount will be micro-burst storms where the winds can rip things like canvas, etc. to shreds.

I can see this also working really well in desert areas where shade would be most welcome, and having power to do something would also be most welcome.

At least we could put up some artificial "shade" trees that are solar power plants, until the real plants could take root in the desert. Could I just have stumbled on the answer to restoration of the Sahara to savanna?