I made the solar book to use as a portable solar energy source to power a small radio or other low power device in the event of a power failure or just for fun. I used two Chronar 6" x 12" solar panels that I bought from a local surplus dealer.
The Solar Book is capable of an output of about 3.6 watts in optimal
That is about 20 times more power than my old Channel Master radio needs to operate so I have plenty of margin to place the Solar Book on a window sill inside the house or use the unit outside in less than optimal light levels and still listen to my radio.
See my Chronar Solar Panel page for more information on the panels.
The Solar Book is about 16 1/2" x 14 1/4" when open and about 8 1/2" x 14 1/4" x 1 1/2" when closed.
Solar book, Channel Master radio, and homemade voltage regulator with two 10 foot power cords.
The solar book is covered with gray speaker cabinet carpeting bonded to the wood with contact adhesive. I used banana jacks for the output connections to the solar book. The banana jacks and toggle switch were installed after the carpeting was attached to the wood.
The panels can be configured electrically in series or parallel with the built in toggle switch.
Parallel switch setting gives an output of about:
6 volts @ 600 ma.
Series switch setting gives an output of about:
12 volts @ 300 ma.
For the interconnecting wire pair on the Solar Book. I decided to
mount the wire on the surface and restrain it with two cable tie
mounting bases. By having one mounting base on an angle and the other
mounting base vertical I was able to minimize the flexing of the wire
when the book is opened and closed.
For the hinge, I used a piano hinge I bought from a local surplus metals dealer for another project. I still had more than enough leftover to use for this project. I cut this section of piano hinge to length with my dremel tool and cut off wheel, and then cleaned it up with a metal file.
The carpeting is cut out so the cable tie mounting bases can sit on the plywood to provide enough clearance.
I routed recesses in the wood for the solar panel snap on contacts and channels for the wires with my dremel rotary tool and router base attachment. I drilled holes for the switch and banana jacks, and epoxied them in place with a two part epoxy. I used 3M Super 77 contact adhesive to bond the carpeting to the plywood panels. I cut the carpeting so the solar panels would sit flush to the wood. The two rubber feet on the corners keep pressure off the panel mounts and contacts when the book is closed. On the right side of the picture you can see a piece of thin cardboard material (office folder) I cut to size to protect the back of the panel.
The contacts that were included with my solar panels are actually
battery snap-on contacts. They seem to be a decent solution for the
way I am using the panels but if you want to use the panels outdoors a
better solution might be to use a conductive epoxy to attach the
After searching around a bit I found that the Keystone #209 Snap-on Contacts sold by Allied Electronics match the contacts that were included with my panels. On the left is the original contact. I modified the contact on the right by bending the barbs flat and the battery contact are down.
When installing the contacts on the solar panels you need to spread the contact open. If you just push the contact on the panel and use the glass to spread the contact you will probably make a mess out of the edge of the glass solar panel.
The battery snap-on contacts were made to be used on plastic molded
cases and there are barbs on the contacts designed to hold them in
I wanted the contacts to make an electrical connection with the solar panels but I didn't want the barbs to tear the deposited metal coating off the solar panels so I bent the barbs down and in line with the rest of the clip portion of the contact. I also bent the battery contact part of the clip down so the solar book can be closed.
You can use the contacts with the barbs facing the top side of the panels but I would still flatten the barbs.
Here is the wiring diagram for the solar book. A double pole, double throw (DPDT) switch is used to configure the solar panels electrically in parallel or series. I used a miniature toggle switch but a less expensive slider switch could be used instead.