Size your whole system
Filled in from your off-grid home setup in Pennsylvania, recalculated just now. Change anything below.
Your daily use and your darkest month decide everything. Put them in and you'll get panels, batteries and an inverter, plus a cost range.
Pennsylvania gets about 2.5 hours of strong sun a day in December, its darkest month (NASA data).
| 25 | Solar panels, 410 W10.3 kW total, sized for your darkest month with 10% to spare |
| 6 | 48V server-rack batteries27.0 kWh stored · about 4.6 kWh usable each |
| 1 | EG4 12000XP (120/240V)Makes 120 and 240 volts for well pumps and big appliances |
Even in your darkest month, the batteries never drop below 60%, and the sun fills them back up every day.
In summer they're full again by 11am, and the extra sun is yours to use.
Starting full at 6pm, the batteries run the night, drop to their lowest around 8am (60%), then the panels make about 19.8 kWh a day in your darkest month against about 18.0 kWh used. After two days they sit at 94%.
Rough one-time cost: $15,500 – $19,000, parts and wiring.
Go deeper: how this works
Panels: daily use ÷ darkest-month sun hours ÷ 0.77 (wires, heat, dust) × 1.1 (margin).
18.0 ÷ 2.5 ÷ 0.77 × 1.1 = 10.2 kWBatteries: daily use × days without sun ÷ usable storage per battery.
18.0 × 1.5 ÷ 4.6 = 6Want it done for your life?
The guides ask how you live instead of how many kWh, then size everything and show the exact picks.