It is unfortunate that this project was met with such criticism. Moreover, I'm somewhat surprised that folks seem to be unaware of how solar technology is actually employed in practical, day-to-day applications around the world. Solar refrigerators using absorption technology, such as this one, have already been developed for use by medical personnel to keep vaccines refrigerated in developing nations. It has been seen as a viable alternative to using the same technology heated by kerosene (propane, butane, etc are typically not available on a reliable basis). There has also been a great deal of recent work in attempting to adapt dual Danfoss DC compressors to run directly off a PV array and store enough energy to work through the dark period for the same application. The results were not favourable.
I have had a quick look at my links but I long since deleted them. MIT, Berkley, and a number of universities have ongoing research projects so if you plug away on web searches you will eventually find their reports and designs. They're not trying to keep them secret, they just get covered up by a lot of commercial mumbo jumbo. There is also a particularly good report on the use of amporphous solar panels in Kenya including efficiency ratings, degradation over time, and durability. Surprising results that run counter to many prevailing attitudes.
One thing to consider about this absorption solar fridge. Electrolux makes an off-the-shelf fridge which runs off of 12 vdc as well as 240v and butane/propane. It does not have a thermostat for the 12v mode, but one can be made for about £5. The unit draws 5.75 amps at 12 volts so figure roughly 72 watts or, on a 70% on cycle, slightly less. The difficulty of routing thermal energy to the absorption unit may end up being less efficient and practical than a couple of decent 80 watt panels to simply drive the built-in heater. Food for thought? I run mine this way.
From the edge of the universe...
Cheers!