Cold storage

Ranked by how cold the store gets and how dependably. A powered refrigerator holds a set temperature whatever the weather. A root cellar is reliably cool from ground contact but tracks the season rather than a setpoint. A zeer pot achieves a useful drop below ambient only while the surrounding air is dry enough for evaporation, a real limitation in Normandy's oceanic climate.

Solutions

• Root cellar (passive cool storage): Uses ground-coupled stable temperature for cool storage with no power input.
• Electric refrigerator: Conventional powered cold storage; can be sized to run on the DC bus.
• Zeer pot (evaporative pot-in-pot cooler): Two nested unglazed terracotta pots with a roughly 4cm layer of wet sand packed between them; evaporation of the sand's moisture draws heat out of the inner pot