Solar Carport

[shark2k]

Very nice! Do you have to clean them often? I want to build something on a small scale for experimenting. I also want it to power something I use, like my computer or few lights. I've read somewhere that cold weather increases PV cell efficiency. I was wondering how much more efficiency i can get from the panel if I water cool it on very hot summer days. I would seal up the back side of the panel and pump cold water from the lake through it.

I don't think you quite understand that based on your next sentence. From my understanding, the efficiency is increased when there is less humidity, not from the panels being cooler. I noticed you are in Florida, which means the panels won't be as efficient as, say, Maine where it tends to be cooler (which means less humidity). I'm not sure if you need to clean solar panels. They are usually placed on your roof (which can be high in some instances). Of course I wonder if there is a benefit from that.

-Shark2k

[shark2k]

Just wanted to give the actual specs of our system. It is gonna be a 4.725 kW system. Based on the calculations the solar company did they say we should produce 4,965 kWh annually and that would cover about 55% of our energy (it's listed as % of ON PEAK Energy Produced by Solar). It will be a grid-tied system with no battery backup. A battery backup would not be with it for us because we do not lose power very often (it is pretty rare for our area).

For a little idea of our energy use, it is 9,086 kWh annually. According to the rep from the company we are actually a little lower than average on the annual energy usage. So it will decrease our energy bill by about half which is nice, so I'm happy (even though it's my parents house).

After thought (since it's in the quote thingy):

Eliminate the production/emissions of:

Carbon Dioxide (CO2) 8,336 lbs/yr
Nitrous Oxide (NOX) 15.6 lbs/yr
Sulfates (SO4) 22.9 lbs/yr
Equivalent of Planting 2 acres of trees

-Shark2k

[TEG]

Oh I have another 80watt panel on my EV that keeps the 12v system topped off and can run the big stereo and TV in the back as long as needed while parked. 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.

--


Regarding the house panels - hours of sunlight is more important than cool panels. I would trade a long hot summer day for a cold winter day. The best would be a long day in summer with a cool breeze.

Also more important than temp is angle to the sun and any possible shading. When the sun starts to drop in the horizon do any trees or buildings cast any shadows on the panels?

[graham]

Very nice! Do you have to clean them often? I want to build something on a small scale for experimenting. I also want it to power something I use, like my computer or few lights. I've read somewhere that cold weather increases PV cell efficiency. I was wondering how much more efficiency i can get from the panel if I water cool it on very hot summer days. I would seal up the back side of the panel and pump cold water from the lake through it.

I probably should clean them frequently to remove the dust that builds up, but I am far too lazy. If I think about it, maybe once a summer when it hasn't rained in a while I turn the garden hose to the roof to remove some of the dust from the beach and salt from the air. Mostly I just wait until it rains to do that for me.

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... but once again, me with the lazy.

However, I do have to do battery maintenance twice a year - which is a drag - so my system is not entirely maintenance free. I could have gotten maintenance free batteries, but they were like twice the price and half the capacity.

[doug]

However, I do have to do battery maintenance twice a year - which is a drag - so my system is not entirely maintenance free. I could have gotten maintenance free batteries, but they were like twice the price and half the capacity.

What kind of batteries are they, and what kind of maintenance is required?

I appreciate your initiative to make your own thread, btw. Complete with links!

[shark2k]

I probably should clean them frequently to remove the dust that builds up, but I am far too lazy. If I think about it, maybe once a summer when it hasn't rained in a while I turn the garden hose to the roof to remove some of the dust from the beach and salt from the air. Mostly I just wait until it rains to do that for me.

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... but once again, me with the lazy.

However, I do have to do battery maintenance twice a year - which is a drag - so my system is not entirely maintenance free. I could have gotten maintenance free batteries, but they were like twice the price and half the capacity.

Really? Did you actually see this happen or did the guy just tell you that? I was under the impression that less humidity made the more of the "rays" reach the panels so they performed more efficiently. Of course I'm not an expert on this stuff (just really interested) so any correct info I get is always good.

As to the cleaning, I always just figured leave it to nature to clean it off .

-Shark2k

[shark2k]

Doug

I have 24 giant lead acid batteries

Of course graham still needs to mention the kind of maintenance, but one of your questions was answered.

-Shark2k

[graham]

What kind of batteries are they, and what kind of maintenance is required?

I have 24 of these guys:


They are 6 volt lead acid in 3 series of 8 (3 banks of 48V). Each are 2 or 3 times the size of a normal car battery and I think they weigh about 150 lbs a piece.

There are two pieces of maintenance required. 1) because they are not sealed, you have to make sure they have enough liquid to cover the lead plates, and 2) every six months they need to be "equalized" where you pop the tops off, and flood the battery with a bunch of current for about 3 hours which boils the sulfuric acid and gets it everywhere (nasty).

Because I use "water miser" caps, I only check the water levels when I do the equalization every 6 months instead of every month like I would if I kept the standard cap.

I appreciate your initiative to make your own thread, btw. Complete with links!

Happy to do my part -- we were going off in the weeds a bit from the "Top Gear" topic

[graham]

Really? Did you actually see this happen or did the guy just tell you that?

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!

[shark2k]

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!

Darn those urban myths .

-Shark2k