Is 600–800 W of Solar and 3–5 kWh Enough?

In August 2026, reports described high-load off-grid systems for RVs, boats and mountain cabins moving into export markets, typically 600–800 W of solar with 3–5 kWh of storage and multiple inputs from PV, vehicle, grid and a diesel generator. What that package can actually carry is arithmetic. At four effective sun hours a day and 700 W of modules, daily yield is about 2.8 kWh; a 3–5 kWh battery at 80% depth of discharge delivers 2.4–4 kWh. Its sensible boundary is therefore a daily consumption of 2–3 kWh: lighting, a laptop, a router, a small fridge, phone charging. Add air conditioning and 1.5 kW for six hours is 9 kWh — a gap of more than three times, which only the generator or the grid can close. One simple rule for off-grid sizing: daily yield should be at least 1.2 times daily consumption, or 1.5 times with no backup; battery capacity is set by consecutive cloudy days, not by peak power.