Off-Grid Load-Audit Worksheet

The load that sinks an off-grid budget is rarely the one you can see. It is the router that never sleeps, the inverter idling at thirty watts around the clock, the six chargers left in the wall out of habit. Individually, nothing. Run across all 8,760 hours in a year, they can quietly out-eat the refrigerator — and every phantom watt you forgot to count is a solar panel and a slab of battery you end up paying for anyway. This worksheet makes you count them.

Fill in a row for everything you actually plan to run. Put the running watts from the nameplate or a plug-in meter in the first column, the surge or starting watts a motor spikes to for a second on start-up in the second, and a realistic hours per day in the third. The sheet multiplies watts by hours into daily watt-hours and keeps a running total as you type — the number you hand to a solar designer, or drop straight into the sizing calculator below.

• Motors — fridges, freezers, pumps, compressors — surge to roughly two to three times their running watts on start-up. That spike sizes your inverter’s peak, not your daily energy, so it lives in its own column.
• Rate the hours the way the appliance really behaves. A fridge compressor cycles on and off; eight hours of running time a day is closer to the truth than twenty-four.
• Don’t skip the last pre-filled row. Standby and phantom loads never switch off, and 24-hour draws add up faster than anything you turn on by hand — the appendix below is there to help you fill it in.

These are the draws that never appear in a quick mental tally because nobody switches them on — they were on before you walked in. The worst offender is usually the inverter itself: many run a 20–40 watt no-load draw just to stay awake, which is half a kilowatt-hour to a kilowatt-hour a day before a single appliance turns on. Add these up and drop the total into the Phantom / standby loads row at the bottom of the worksheet.