Off-grid from zero · lesson 3 of 12

Water comes first

Size how much you use, pick the source that fits the land, and plan storage and treatment before anything electrical.

Power gets the attention, but water is what decides whether the place is livable. It is also the system most tied to the land itself: a drilled well, a spring, a roof, a pond, or a truck. Each one sets a different electrical load, a different budget, and a different set of habits.

Start with use, because everything downstream is sized from it: gallons per person per day, then storage in days, then the source that can sustain it in the driest month. The planner now carries all of those choices, and the water tools size each piece.

Numbers to carry
  • Moderate off-grid use is about 15 gallons per person per day; conservation households run 5.
  • A 1 hp submersible pump draws about 1,200 W running and can spike to roughly 4,000 to 7,000 W on start, so check the motor's locked-rotor rating on the nameplate before sizing.
  • A 1,000 square foot roof in 38 inches of rain yields about 19,000 gallons a year after losses.
Read
Use
Do before the next lesson
  • Pick your water source in the planner and note the pump load and surge it adds; that number follows you into the power lesson.
  • Size storage for at least a week, a month if you haul or catch rain.
  • Schedule a water test for the source, and write down where the test goes.
← Lesson 2 Lesson 4: Loads before panels →
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