how to built a solar panel-πως να φτιάξεις φωτοβολταϊκά

bought a couple of bricks of 3 X 6 mono-crystalline solar cells. It takes a total of 36 of these type solar cells wired in series to make a panel. Each cell produces about 1/2 Volt. 36 in series would give about 18 volts which would be good for charging 12 volt batteries. (Yes, you really need that high a Voltage to effectively charge 12 Volt batteries) This type of solar cell is as thin as paper and as brittle and fragile as glass. They are very easily damaged. The seller of these solar cells dips stacks of 18 in wax to stabilize them and make it easier to ship them without damaging them. The wax is quite a pain to remove though. If you can, find cells for sale that aren't dipped in wax. Keep in mind though that they may suffer some more damage in shipping. Notice that these cells have metal tabs on them. You want cells with tabs on them. You are already going to have to do a lot of soldering to build a panel from tabbed solar cells. If you buy cells without tabs, it will at least double the amount of soldering you have to do. So pay extra for tabbed cells.

There are lots of other sizes of solar cells besides 3 X 6 inches available. You could use larger or smaller cells for your panel. Just keep a few things in mind.

• Cells of the same type all produce the same voltage no matter what size they are. So the same number of cells is always needed.
• Larger cells produce more current (Amps) and smaller cells produce less current.
• The total power your panel can produce is determined by Amps X Volts.

So using bigger cells produces more power, but the panel will be large and heavy. Using smaller cells keeps the panel small and light, but won't produce as much power. Also, mixing cell sizes is not a good idea. This is because the current your panel can produce will be limited by the smallest cell in the group and the larger cells won't work to their full potential. 
The cells I settled on are 3 X 6 inches in size and are rated at roughly 3 amps. I will wire 36 of them in series to get a little over 18 volts. The result should be a panel capable of delivering almost 60 Watts of power in bright sunlight.
Getting the wax off the cells is a real pain.I would recommend buying from someone who doesn't dip their cells in wax. The first step is a bath in hot water to melt the wax and separate the cells from each other. Don't let the water boil or the bubbles will jostle the cells against each other violently. Also, boiling water may be hot enough to loosen the electrical connections on the cells. I also recommend putting the brick of cells in the water cold, and then slowly heating it up to just below boiling temperature to avoid harsh thermal shocks to the cells. Plastic tongs and spatulas come in handy for teasing the cells apart once the wax melts. Try not to pull too hard on the metal tabs or they may rip off. I found that out the hard way while trying to separate the cells. Good thing I bought extras.

The initial hot water bath for melting the wax is in the right-rear. On the left-front is a bath of hot soapy water. On the right-front is a bath of hot clean water. All the pots are at just below boiling temperature. The sequence I used was to melt the bricks apart in the hot water bath on the right-rear. I'd tease the cells apart and transfer them one at a time to the soapy water bath on the left-front to remove any wax on the cell. Then the cell would be given a rinse in the hot clean water on the right-front. The cells would then be set out to dry on a towel. You should change the water frequently in the soapy and rinse water baths.

All cells need to be soldered together in series.

Each solar panel in a solar power system needs a blocking diode in series with it to prevent the panel from discharging your batteries at night or during cloudy weather. use a Schottky diode with a 3.3 Amp current rating. Schottky diodes have a much lower forward voltage drop than ordinary rectifier diodes, so less power is wasted. Every Watt counts.You ken get a package of 25 31DQ03 Schottky diodes on Ebay 

		Parts
		Solar Cells polyester or glass
		silicon
		diode
		inverter Tab, Bus ribbon 25m & rosin flux

A Generator
B Inverter
C Electricity meter for injection
D House connection point
E Public electricity network
F Electricity meter for consumption
G Consumer load

A Generator
B Solar Charge Controller
C Battery
D Generator connection box
E Current Consumer (12 V-)
F Boiler
G Storage tank