Size your whole system
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.
Utah gets about 3.2 hours of strong sun a day in December, its darkest month (NASA data).
| 8 | Solar panels, 410 W3.3 kW total, sized for your darkest month with 10% to spare |
| 3 | 48V server-rack batteries10.5 kWh stored · about 4.6 kWh usable each |
| 1 | EG4 6000XP (120V)Runs everything you plug in |
Even in your darkest month, the batteries never drop below 69%, and the sun fills them back up every day.
In summer they're full again by 10am, and the extra sun is yours to use.
Starting full at 6pm, the batteries run the night, drop to their lowest around 8am (69%), then the panels make about 8.2 kWh a day in your darkest month against about 7.0 kWh used. After two days they sit at 96%.
Rough one-time cost: $7,500 – $9,000, parts and wiring.
Go deeper: how this works
Panels: daily use ÷ darkest-month sun hours ÷ 0.77 (wires, heat, dust) × 1.1 (margin).
7.0 ÷ 3.2 ÷ 0.77 × 1.1 = 3.1 kWBatteries: daily use × days without sun ÷ usable storage per battery.
7.0 × 1.5 ÷ 4.6 = 3Want it done for your life?
The guides ask how you live instead of how many kWh, then size everything and show the exact picks.