Building the second solar panel

The last solar panel is completed but not installed.  As can be noted I have used both a different type of cell  (purchased from Renewable Energy Engineering ) and ones that are individually encapsulated. Each cell is sealed so I have had to hook three in series to get the necessary voltage. There are five rows, hooked in parallel, to provide the higher current. While I have not had sun for four days, I was able to briefly get one amp from it yesterday. I will complete the testing this weekend and then install it on the roof with the other panels. I will also install a junction box and larger gauge wire to the solar regulator.

 

The solar panel box is made from plywood and 1X2’s. The buss is made of copper foil as are the interconnections. I built it this way so that each cell could be measured should one go bad.

 

The observations of the battery system, which has been powering the TV, DVD player and satellite box, show that my original calculation that I could run for six days without sun was pretty close to being correct. As we have not replenished the batteries with any appreciable amount of current for four days I have noted that the battery voltage has gone from 12.8 VDC to 12.4 VDC. The system runs for a bit more than four hours in the evening and two and a half in the morning. The amp meter shows a combined draw of about 9 to 12 amps (depending on lights and if the DVD player is on). On a very bright day I can get about 5 to 6 amps from the solar panels (when the new panel is installed I should get close to 8). If you do the math, using a normal solar day for Dallas, I am able to put back just slightly more than I use. Therefore, so as long as I have excess battery capacity and at least three days of sun per week, I can run just fine.

 

However, it does prove that either additional solar panels are necessary or that I need to add the wind turbine as an additional source of energy.

 

The new panel puts out 18.4 volts at 1.51 amps DC as tested at 10:30 CDST in Dallas. This is right where the vendors calculations  said it would be.

 

As can be noted in the picture, I have left some room on the bottom to add two more rows of cells.

 

As seen in the photographs, I have put a piece of Plexiglas on top of the box holding the solar cells. Since we get frequent thunder storms, with hail, in the Dallas area, this is a small piece of insurance that the panel will make it thorough one of these storms.

NOTE:

Chris, at Renewable Energy Engineering, is a great guy to talk to about renewable energy and more specifically, solar. He and I spent a solid hour on the phone talking about systems.

Herb & Barbara our interests and family