Joey Hess designed the first Fridge0 a year ago: it uses a standard chest freezer with added thermal mass, a simple controller, and a photovoltaic panel that effectively stores sunshine as coldness, obviating the need for expensive backup batteries. The Fridge0 is an advance on traditional off-grid 12v solar fridges that assume that solar panels are expensive and inefficient; by exploiting modern PV technology, Hess says “A kilowatt of solar panels provides enough power to run a conventional fridge on even most cloudy days, and costs less than a commercial offgrid fridge.” (via Kottke)
Fridge0: an open source hardware solar fridge with no battery requirement
