Check the things you run, adjust how many and how many hours a day, and we'll estimate your daily power use and the solar panels and batteries to cover it. Great for a ballpark before you talk to an installer.
1. What do you run?
🔋 Your estimated system
Daily power use—
Recommended solar array—
≈ 400W panels—
Battery — lithium—
Battery — lead-acid—
Lithium batteries can be drained deeper (about 80%) than lead-acid (about 50%), so you need less lithium capacity for the same backup. The cheapest power is always the power you don't use — efficient appliances shrink the whole system.
Rough planning estimates using common rules of thumb (about 75% system efficiency). They are not a substitute for a professional load analysis and design. Have batteries and wiring installed by a qualified pro and follow local codes.
Why sizing matters more off-grid
On the grid, running one more appliance just means a slightly higher bill. Off-grid in Apache County, it means your panels and batteries either cover it or they don't — there's no backup grid to lean on when a system is undersized. That's why most experienced off-gridders out here oversize a little on purpose, especially battery capacity, since winter days are shorter and cloudier and a system sized tight for summer sun often comes up short by December and January.
Lithium vs. lead-acid, in plain terms
Lead-acid (including AGM) batteries are cheaper up front but shouldn't be drained past about 50% regularly without shortening their life, so you need roughly double the rated capacity to get the same usable power. Lithium (LiFePO4) costs more per battery but can be drained to around 80%, lasts many more charge cycles, and handles our summer heat better — which is why most new off-grid builds in the high desert lean lithium despite the higher sticker price.