Making a 1 Watt Solar Array.

I love my neighbor’s garbage I call them the parts department. In this, instructible I am building a Solar Array out of 30 solar lights my neighbor threw out.

For this project I am only going to use 18 of the solar cells for the array I am building. The array will be able to charge a 12 volt 10 watt hour battery in a day. The total cost of building this array is about 5 dollars, a comparable array or solar cell can run you 60 dollars.

Since all the parts are salvaged, I will test every thing every step of the way, I don't want to completely assemble the array only to find out one of the components I used is faulty.

For testing you will need a multimeter.

Step 1 The Lights.

My neighbor threw out 3 different styles of solar lights.

I took them apart and kept the tops with the solar cells  and electronics.

At this point you don’t need tools all the parts clip or press together.

The white spot next to the solar cell or in the solar cell is a photovoltaic cell the photovoltaic is used to set the light into charging or lighting mode.

Comments

[Josehf Murchison]

If you do make an array make an instructible on it and here is a little advice.

Try not to mix different makes of cells in string series to be sure you don’t create an over current in a cell in the string or the string may fail if a cell burns out.

With solar cells, you should always have a diode to prevent a back current from batteries and the other strings of solar cells in the array hooked up in parallel.

Back currents can drain your battery at night or burn out a cell string even when you are not using the array.

There is a voltage drop across a diode, try to pick a diode with the smallest voltage drop.

Small cells like the ones I used create a small current so if you use diodes rated for 1 amp you should be safe.

Make sure the diode is rated for a voltage greater than the string voltage generated by the string, the 1N5819 Schottky Diode is a good diode it is rated for 40 volts and has a voltage drop of less than 1 volt.

High-speed diodes have the small voltage drops and Germanium diodes have voltage drops as low as .45 volts.

Last seal up the array so morning mist and rain wont short out the array, you wont believe how many commercially available solar cells cannot be let get wet.

Hope this is helpful

Joe

[cobourgdave]

I like this instructable. I had not considered the garden light solar panels in this way. Clearly I am going on a scrap hunt amongst the garage sales this spring. Nice instructable with good clear instructions and good pics.
Well done sir.

[wouternet]

I'm only seeing volts here. How much current can it deliver?
It will probably be about 150 ~ 200 mA....

[wouternet]

Plastic doesn't oxidize. It decomposes or degrades.
Metal oxidezes. And oxidation isn't caused by UV light, it's caused by water and oxigen.

[paintphone]

So I used your instructable and made an upcycled solar pannel myself, here is what i came up with: 5 glass cells and a wopping 16.4V thanks so much for helping me understand this more.

[Josehf Murchison]

cool it looks nice also
Joe

[paintphone]

I love just driving down the road and seeing some perfectly good solar lights, just hazed over and in need of a quick scrub with 1000 grit wet sandpaper and a quick coat of clear or 5. Defiantly going to a new home  a new home. This is going to be very useful for me. Great Instructable!

[dasimpson1981]

sorry to tell you but the voltage you are getting is not the voltage you need to charge a 12 volt battery from solar most solar panels are 18-21volt

[Josehf Murchison]

I have checked out commercially available solar cells of the same power they only go up to 15 volts max 12 volts average. Even the charging system in a car only goes up to 14 volts.

[drbill]

I have a 10 panel array. Each panel produces 22V @ 1.18A/20 W

My array produces 200W @ 11A.

I charge 2 Deep Cycle Marine batteries and run them through an inverter to

power a 625W device.

If I wire them differently I can get 220V out of them.

[Josehf Murchison]

If the solar panels don’t have a diode in them, I hope you put a diode between the solar panels in parallel.
I get a much larger wattage.

I x V = W
1.18a x 22v = 25.96 watts
25.96w x 10 = 259.6 watts

If you connect them in series you should get 220 volts at 1.18 amps and 259.6 watts.
You can connect them together two different ways.

[Josehf Murchison]

Sorry wrong diodes 1N5403 in the top schematic and 1N5400 in the botom.

[dasimpson1981]

deep cycle batterys are not to be charged the same way as a car battery different voltages etc but all solar info i have read says 18v-21 i guess that way it can start charging sooner with less light

[Josehf Murchison]

You want more build your own.
I have commercially available solar cells.

[dasimpson1981]

i will be doing soon i will go round collecting the end of crimbo ones every one seems to scrap

[Josehf Murchison]

If you do make an array make an instructible on it and here is a little advice.

Try not to mix different makes of cells in string series to be sure you don’t create an over current in a cell in the string or the string may fail if a cell burns out.

With solar cells, you should always have a diode to prevent a back current from batteries and the other strings of solar cells in the array hooked up in parallel.

Back currents can drain your battery at night or burn out a cell string even when you are not using the array.

There is a voltage drop across a diode, try to pick a diode with the smallest voltage drop.

Small cells like the ones I used create a small current so if you use diodes rated for 1 amp you should be safe.

Make sure the diode is rated for a voltage greater than the string voltage generated by the string, the 1N5819 Schottky Diode is a good diode it is rated for 40 volts and has a voltage drop of less than 1 volt.

High-speed diodes have the small voltage drops and Germanium diodes have voltage drops as low as .45 volts.

Last seal up the array so morning mist and rain wont short out the array, you wont believe how many commercially available solar cells cannot be let get wet.

Hope this is helpful

Joe