Off-Grid Countdown & Load Planner

1. Find your real deadlineFirst hard freeze, minus a buffer, minus the longest lead time you are carrying. That date, not the closing date, decides which phone call comes first (Chapter 1).

2. Size the power you actually needList only the loads that keep you alive and reachable. Daily watt-hours become an array, a battery and an inverter with the book's four lines of math (Chapter 5).

3. Replace the placeholdersEvery lead time here is illustrative. One afternoon of calls to your county and two or three drillers gives you real numbers; type them in and the dates move.

Example from the book:

Countdown (Chapters 1 & 9)

Closing / start date

County average first hard freeze

Your county extension office or the USDA hardiness map gives the average first hard freeze (28°F). Use the average, not the record.

Buffer (days held in reserve)

Default three weeks: the permit that runs long, the delivery that slips, the week you lose to rain.

Lead times, in weeks (placeholders until you call)

Well driller (booking → rig on site)

Solar equipment shipping

Septic site evaluation

Septic permit (after evaluation)

Septic install (after permit)

Propane tank account + delivery

Electrical / mechanical permits

Temporary dwelling permit

The well is part of year one (otherwise it is deferred, as the Reference Build does) Solar equipment is ordered in year one

Minimum-viable load (Chapter 5)

Nameplate watts × hours per day, or type the watt-hours straight in when you know them (a fridge's yearly label ÷ 365). Leave a row at 0 if you will not run it.

Site and hardware

December peak sun-hours per day

Your Chapter 2 site number. Use the winter figure, never the brochure's summer one.

Days of autonomy wanted

How many cloudy days the battery alone must carry.

Panel size you will buy (W)

Largest motor's running watts

Well pump or fridge compressor. The inverter is sized to its starting surge.

Your countdown

Your power system

The rules behind these numbers

Your real deadline is the first hard freeze minus the buffer minus the longest lead time in your chain — not the closing date. Whichever clock has the earliest latest-start is the first phone call. Chapter 1.
The septic clocks run in series. Evaluation, then permit, then install; the evaluation's latest start carries all three. The site plan and the septic evaluation are booked in week 0 even though the toilet is built last. Chapters 1, 7 and 9.
Array size = daily watt-hours ÷ (December peak sun-hours × 0.75). The 0.75 is the winter derating for wiring, charge-controller and low-angle losses; round up to whole panels. Chapter 5.
Battery size = days of autonomy × daily watt-hours ÷ 0.8, because LiFePO4 gives 80% usable depth. Chapter 5.
Inverter size follows the largest motor's starting surge, two to three times its running watts at the floor; check the device manual. Chapter 5.
Generators: never indoors, at least 20 feet from the dwelling, a transfer switch not a window cord, and a carbon monoxide detector. Chapter 5.

This planner applies the book's arithmetic to numbers you type in. It is not engineering, electrical or permitting advice; every county enforces its own codes and lead times, and a licensed electrician sizes and inspects the real system.