The 4WD Solar Fridge Project: Details 1 (2001 posting from old site – Page 2)
This system consists of a solar electric panel, a storage battery, a voltage regulator/diode, electrical wiring, various mounting hardware, and modifications to the vehicle to mount the hardware and allow sleeping and storage.
These pictures were taken on the day I de-commissioned the system from the vehicle (March 17, 2001). The solar system had been up and in use off and on since January 1995 (6+ years) without any problems except for the battery. The vehicle on the other hand (a 1986 Isuzu Trooper) had seen better days, and was too old to take to the desert anymore.
The panel is made from 4 surplus photovoltaic panels bought from Solar Electric, Inc. They were only $50 each if you bought four, for a total of only $200. If you’ve ever priced photovoltaics, you’ll know this is very cheap.
These tempered plate glass panels were originally part of a solar demonstration project put on by Arco in the Arizona desert in 1984. They were apparently used in conjunction with mirrors that concentrated the sun to a degree, which accounts for the brown color. They only lose a couple of percentage points in efficiency from being browned – no big deal.
I built a frame from wood, wired the 4 panels in series, and sealed and glued it up with some non-acidic black silicone sealant (Dow 739). The sealant was also used to seal the holes I drilled where the wires entered the roof of the truck. The wood was given a coat or two of spar varnish (what you use on boats).
In the photo above you can see where the positive and negative wires enter the roof and were sealed with silicone. You can also see some of how the panels were mounted: the luggage rack hardware was modified to hold the panels. Holes were drilled in the mounts, and custom fittings made from wood and brass were put in place to hold the long brass bolts that served as the mounting point and hinge for the panels.
The original machine screws that held the luggage rack mounting hardware on the roof were not strong enough to hold the panels firmly while driving over rough, rocky desert roads I discovered, so I drilled larger holes in the roof and used brass bolts. I had to cut through the ceiling liner to get at the bolts from inside the SUV (see next page).
