Solar Panel - Prototype One

After removing all the unusable bits of cell from the package I ended up with 99 cells that were at least full width or full height. I'm amazed at how fragile the cells are so its not really surprising that a few didn't survive the trip.

I found that securing any cracked cells to the glass with tape helped to avoid any further damage but get it right. There is no chance of removing the tape without destroying the cell. I'm not sure whats going to happen when the tape has been in the hot sun for a summer but hopefully everything is so tightly sandwiched that it won't matter.

The back view

I also found that soldering the panels while they were in contact with the glass was a stupid idea. The glass conducts the heat away far too fast to be able to get a good joint.

A bit of forward planning would have gone a miss. I ended up having to run a wire down the middle of the panel because I oriented both strips of panels the same. This meant the positive ended up at the top. No good when I want to connect them in series.

The front view

The silicon sandwiched between two sheets of glass takes a long time to set. Seal it and put it away for a week before playing with it. I used a bathroom silicon that reacts with water so hopefully the remain air trapped between the glass will be fairly dry.

Best result so far was 1.2Amps at 5.2 volts = 6.24w. Which is reasonably pleasing considering the state of the panels and the terrible soldering job and having to run the connecting wire down the center of the panel.

The panel cost about $6 for the cells and a couple of dollars for silicon and connectors. Call it $10 which makes it ~$1.60/watt. A lot cheaper then buying them but no 25 year output warranty.

Getting moisture inside the panel will be the biggest issue. We'll see how they go when I mount them outside. A local company Terranova operates a waste exchange. One of their clients is advertising factory second double glazing for free. I'm thinking I might be able to pop the end off and slide the cells inside. This would probably keep them dryer and be a cheap source of glass.

I metered a couple of power points around the house for a few months and found the following;

Fridge uses 0.72KWh/day
Internet connection, wireless router and switch use 0.24KWh/day

My first goal is to get the internet gear running off the panels. Assuming I get 6 hours of sunlight a day (very optimistic) I'd need a 40W solar array so maybe if I have a 100W solar array I might be able to do it. So far I've observed that 12 cells is required for 6W so I'd need 200 cells to archive this goal. Sounds like a lot but its how many I ordered so all I need now is more glass and lots more patience.