The Field Calculators → Food & Storage
Food & Storage
Freezer & storage space
How much freezer you need for the beef, and what it costs to run.
Result
Food to store400 lb
Freezer running wattage100 W
Duty cycle35 %
Electricity price0.15 $/kWh
Freezer space needed
11.4 cu ft
About 35 lb of packaged meat per usable cubic foot.
Running cost
$46/year
307 kWh per year.
Daily energy
840 Wh/day
Useful if it's going on a battery or solar system.
Value at risk
$2,400–4,000
Which is why the $12 alarm is the first build in the book.
What this will not do
- Build the $12 freezer alarm. An ESP32 and a temperature probe, reporting on your own network. A tripped breaker or a bumped plug ruins everything in 18–30 hours, silently, and the alarm pays for itself the first time.
- A full freezer is cheaper to run than an empty one — the mass holds the cold. Jugs of water fill the gap and double as your emergency water.
- Chest freezers use substantially less energy than uprights: cold air doesn't fall out when you open the lid.
The full build and the reasoning are in Chapter 39 of the guide.