How far does a 1.8 kW off-grid solar system go?
Modeled month-by-month output for a 1.78 kW array in Hilo and Kailua-Kona vs. Phoenix, Denver, Seattle and Burlington, VT, plus what a 314 Ah 12 V lithium bank actually stores.
I've lived off grid for 22 years, in a treehouse in a remote part of Hawaii Island. I'm not an electrician, just someone who has had to understand his own system because parts are always failing and troubleshooting is part of life.
These guides are first-hand: each one starts from my own setup and works the numbers from manufacturer manuals, datasheets and NREL's PVWatts model, with the arithmetic shown. Nothing here is a measurement I didn't take. If you spot a mistake, I'd like to hear about it.
Modeled month-by-month output for a 1.78 kW array in Hilo and Kailua-Kona vs. Phoenix, Denver, Seattle and Burlington, VT, plus what a 314 Ah 12 V lithium bank actually stores.
How much charger a Honda EU2200i can run into a 12 V, 314 Ah LiFePO4 bank, and how long a recharge really takes, worked from the Honda, EVE and PowMr manuals.
How many hours a 4.02 kWh, 12 V LiFePO4 bank runs Starlink, laptops and networking, what the inverter costs just by being on, and how to check the arithmetic against your own system. Worked from EVE, Starlink, Victron and Renogy specs.
Weekly, monthly and yearly checks for a small off-grid solar and LiFePO4 system, a generator service table, cabin storage notes and a printable battery maintenance log. Each line is taken from the makers' manuals.
Daily loads in Wh, NREL peak sun hours for nine US regions, usable battery Wh, controller and inverter sizing, worked through for a weekend cabin and a full-time cabin, with my own system as a reference. Wiring and fusing are left to the manuals and an electrician.
Figures in these guides are modeled or worked from published specs, not measured. Follow your own equipment's manuals, and get a qualified electrician for anything you aren't sure about.