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Discussion Starter #1
A solar panel is a device that consists of a few bits of silicon, usually glued under glass, that you put in the sun to generate electricity. There are no moving parts and very little to wear out. A solar panel will go on producing electricity year after year with only one proviso ... it must be in full sun to produce full power. Forget about shade tolerant panels and other marketing hype, sunlight = power from your solar modules, shade, overcast, rain and all the inclement stuff means nil or very little output.

Some useful information to know:
• A solar panel is supplied ready to mount. It will have an aluminum frame that you use to attach the panel to any surface. Typically this will be with tags, strips of metal, wood or anything else that suits the particular location. Because aluminum reacts with some dissimilar metals you should either use aluminum for tags or separate different materials with a non-conductor like plastic.

• A solar panel should have a tilt angle wherever possible to face it square on to the sun at midday. The correct tilt angle is the latitude of the location in degrees. At 19 North, (here in Haiti) the tilt angle should be 19 degrees … but this is an average year round angle. If you want maximum output on winter days the tilt angle should be latitude plus 10-20 degrees. Here in Haiti I mount (fixed installation) panels at around 30 degrees. A few degrees here and there is not critical. If you are mounting your panels flat, such as on the roof of a caravan they will still work fine, you will however get slightly less power per day compared with a correctly tilted array.

• No matter what a solar panel salesman tells you there is really no such thing as a “shade tolerant” or “cloud tolerant” panel! A small loss of sunshine equals a large loss of output. A slight overcast typically wipes out 50% of a panels output. Partial shading from that tempting tree in the desert will mean no battery charging. Do not believe otherwise!

• A solar panel is not magic! If you use a 60 watt light globe for one hour at night you will need full sun on a 60 watt solar panel for one hour + to generate what you have used.

• Your solar panel will typically be 12 volt rated although there are now some 24 volt panels on the market. You will need pairs of panels to generate 24 volts if you use 12 volt panels. You will need your panels in groups of four for a 48 volt system.

• A 12 volt panel will have a typical output of 20 volts! You need an excess of voltage for power to flow from your panel to your battery.

• A solar panel will either be supplied with a junction box containing a positive and negative terminal or with “flying leads” which are your positive and negative connections.

Let me know if you found this helpful, I will post more Information working upto to a full "off-grid" system as I get time.

Regards

Amos
 

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Discussion Starter #4
so what is the best type of solar panal the monoCrystalline ones are the best i've heard
Monocrystalline panels are claimed to be the best and I'm sure that the lab data would confirm this, they are also more expensive than Polycrystalline panels. If you can afford the extra expense and are in a zone where you get an average of 7 sun hrs per day then Mono would be the way to go.
 

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I would agree with most of this except the shading issues.

When we first installed my unit i had my panels on my roof. It was VERY overcast that day so I figured hey we are good right, shading is supposed to make it safe, etc.

I almost fell off the roof when I got shocked- not that the shock was that much but I wasn't ready for it.

I think it depends a lot on the SIZE of the panel and array. A smaller panel WILL be more apt to a big reduction in power during shading.

We run 14 Kyocera 130 watt panels. I've went out on NIGHTS with full moon and checked the charge controllers- the panels were receiving power.....

The shading issue might have been more true 20 years ago.

OBVIOUSLY you want the best unobstructed view south you can get, and cut everything you can to get and keep the longest view, but I think the shading issue is way overblown in most cases.

Here is one of the systems we run-

 
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