Solar Carport

[dpeilow]

I was pretty gutted recently when a friend of mine who works on a tug boat said they had to throw away several perfectly good 2900Ah batteries because they were no longer allowed to use unsealed ones. Would have been the basis of a good system.

Anyway - I moved the other posts in the TG thread over here (feel the power :biggrin - I hope that makes sense to everybody.

 

[graham]

I was pretty gutted recently when a friend of mine who works on a tug boat said they had to throw away several perfectly good 2900Ah batteries because they were no longer allowed to use unsealed ones. Would have been the basis of a good system.

That is horrible!

Anyway - I moved the other posts in the TG thread over here (feel the power :biggrin - I hope that makes sense to everybody.

Thanks very much!

 

[donauker]

He just told it to me, I have not experienced it first hand. Although I have heard other people say similar things, so if it is untrue it must be a common urban myth!

Hard to say if you could see a difference by doing that, but solar panel output is very much affected by heat not by humidity.

 

[doug]

I don't see how humidity would affect the operation of the solar panel itself. Perhaps it has to do with fewer photons making it to the panel do to atmospheric absorption.

 

[graham]

I have never really noticed any difference in PV performance related to humidity... unless you count clouds / fog. Aptos can get very foggy, and the fog rolling in plays havoc with the amount of juice produced.

 

[TEG]

I met a guy once who used to hose down his panels on hot days because cooling the panels would make his meter spin faster...

By the way, when I asked my solar panel provider about cleaning them he said it is a good idea to hose them down a couple of times a year, but he said do it when the panels are not hot because it could damage them. I gather there was some concern over thermal shock. I wonder if the glass could break from cold water hitting hot panels?

 

[doug]

I have never really noticed any difference in PV performance related to humidity... unless you count clouds / fog. Aptos can get very foggy, and the fog rolling in plays havoc with the amount of juice produced.

In the case of fog, it's a scattering issue more than absorption, since the water is in a liquid phase (suspended in the air). Atmospheric water (gas phase) absorption is a problem for mid and far IR, but not so much for visible radiation.

 

[doug]

By the way, when I asked my solar panel provider about cleaning them he said it is a good idea to hose them down a couple of times a year, but he said do it when the panels are not hot because it could damage them. I gather there was some concern over thermal shock. I wonder if the glass could break from cold water hitting hot panels?

A sharp thermal gradient could also damage the Si or cause metal-semiconductor contacts to fail.

 

[vfx]

Oh I have ... 80watt panel on my EV that keeps the 12v system ... That panel is sized for RV type use where it is just over 12v so you don't really need a regulator. It has a cheap control box that just cuts out the panel if it gets over voltage.

TEG can you give some details on this? I want to put up a small panel with a motorcycle battery (Own it) with a few strings of Xmas LEDS (own them) as a stand alone system.

 

[shark2k]

I don't see how humidity would affect the operation of the solar panel itself. Perhaps it has to do with fewer photons making it to the panel do to atmospheric absorption.

I'm not really sure where I heard that humidity affects the performance of solar panels. I don't think it was my solar guy. It could have been somewhere on the internet I read it or thinking about it now, I think I might have extrapolated it from what my solar guy said. I think he mentioned they are more efficient in the winter (due to the panels being cooler) and I might have (for some stupid reason) connected that with humidity (stupid on my part). So sorry for any misinformation I gave, I did not mean to do that.

-Shark2k

 

[TEG]

TEG can you give some details on this? I want to put up a small panel with a motorcycle battery (Own it) with a few strings of Xmas LEDS (own them) as a stand alone system.

You can find all sorts of info on RV solar kits from google.
Here is one link:
RV Solar Power Kits, Portable RV Wind Generator

This is the panel I used:
Sharp NE-80EJE | Sharp 80 Watt Solar Panel - Solar Power Panel

 

[vfx]

You can find all sorts of info on RV solar kits from google.
Here is one link:
RV Solar Power Kits, Portable RV Wind Generator

This is the panel I used:
Sharp NE-80EJE | Sharp 80 Watt Solar Panel - Solar Power Panel

Thanks!

Funny, Solar is never as cheap as i think it should be...

 

[AntronX]

Does anyone know what happened to that huge solar panel installation at google headquarters? They used to have real time performance monitor page, but now i cannot find it. I would like to see their total energy generated to date.

 

[TEG]

Video

Yeah, I don't see the online power tracker anymore.
It used to look like this:

Archive.org has a copy of the old page

All the old links seem to take you here now

 

[AntronX]

That's it. Wonder why they took that tracker page down. I hope their PV system is still running.

 

[SByer]

Barry, great picture. Are those SunPower 230s up there? Our roof is fragmented like yours, and we'll have a mix up vertical and horizontal orientation on the panels.

 

[Barry M]

Thanks! I originally engineered it with the Sun Power panels, but later switched to BP 175 so I could use micro inverters. As you can see, I have a huge sycamore tree that gives me some shade "challenges". This way, every panel's output does not affect the rest of the array. I have about 3kW total.

 

[Kevin Harney]

How do I determine what size panels I need for my usage and what square footage they will take up on my roof ?

 

[AntronX]

They will take up 0.124231 sq. ft / Watt
So, if you want 4000 Watts of panels, you will need at least 497 square feet.

 

[Kevin Harney]

so how does that translate to the usage I get at home which is Kwh/ month?