I found a really thorough article on an icy-ball style unit, abbreviated SAAR, done as a senior ME design project. The document includes a wealth of practical information, as well as a survey of the dominant intermittent solar refrigeration processes. It is obvious the prototype worked, as the team published charts and graphs describing operating data under typical observed conditions.
http://www.solaripedia.com/files/1113.pdf
Another site to see is Energy concepts and the ISAAC system. Be sure to surf around, as the info is scattered on the site (like most commercial pages).
http://www.energy-concepts.com/_page..._ice_maker.htm
Here is a STEVEN build, with pics and bill of materials:
http://www.free-energy-info.com/P13.pdf