Do you know that such things exist?

http://www.monash.edu.au/pubs/eureka/Eureka_95/fridge.html

With no back-up available, I believe refrigerator goes to sleeeep in absence of Solar energy.

Without batteries, how will it function in low-light conditions?

You need Solar Photovoltaic panels to supply the electrical power to drive the refridgerator compressor.

You don't say how big the refrigerator is. You can buy ice chest size coolers using peltier effect cooling for your car. Add enough solar cells to provide enough 12-v power and you're all set. Add a few more to keep a battery charged and you're covered for nights, but you'll need a lot of batteries (probably 8-12 car-size bateries) and solar cells to charge them.

The Peltier effect methods are very inefficient, about 5%. The best type are the absorption fridges that use the heat directly shone on the back and have 6 inches of foam insulation and dual seals and plastic trim to stop edge leakage to get you through the night. These are sold commercially. Better ones have a tracking array and use a heat transfer fluid. = $$.

a simple search gives this list.

http://www.google.ca/search?hl=en&q=solar+%2Brefrigerator&btnG=Google+Search&meta=

I am currently developing such a refrigerator, but I'm afraid that it won't be available for at least another 12 months. What is the application ?

Deseng

I have seen advertisements for fridges in recreational vehicles that can be powered by 12V DC, 120V AC, and propane. Before rural electrification took over it was possible to buy fridges that used propane. They used heat to pressurize a gas, which was then liquified, probably by releasing the pressure which would give off heat, and the liquid refrigerant was circulated through the cooling coils in the fridge where it became a gas again and absorbed heat and the merry go round went round and round.

A solar fridge may not need photovoltaics and batteries and inverters. A solar concentrator could provide the energy to heat and pressurize the gas. Effective insulation and some sort of solid objects to serve as thermal sinks and hold cold would get you through the nights and cloudy days.

A chest type cooler would be better than a vertical one as the cold would not fall out each time you opened the door.
I wish I better understood the technology but it does exist and it does work.

sun can be focussed on the hot end of an absorption refrigerator. Designing for this make it more efficiebnt. Fallback is heat from any flame, propane etc.

Good design with 5" foam and zero air leak and zero metal path to ambient lets it endure the night. Cold mass internally helps as well.

www.SunDanzer.com build a few dozen such units between 1996 and 2003.