A 30-amp RV is the most common shore-power configuration on the road today. Travel trailers, smaller fifth wheels, and most Class C motorhomes use a single 120V/30A inlet, which translates to a theoretical maximum of 3,600 watts of incoming power. The question almost every owner ends up asking — usually after the third campsite without a hookup — is how much rooftop solar it takes to actually live like that without a generator.
Short answer: most 30-amp RVs do well with **400 to 800 watts of solar** paired with a 200–400Ah lithium battery bank. The reason the range is so wide is that “30-amp” describes the shore connection, not your daily energy use. A weekend boondocker who runs LED lights, a propane fridge, a vent fan, and charges phones may only need 300–400W. A full-timer running a 12V compressor fridge, occasional induction cooking, and a Starlink dish can push 1,500–2,500 watt-hours per day and needs closer to 800W on the roof.
## Step 1: Estimate daily watt-hours, not just watts
Solar sizing is a watt-hour problem, not a watts problem. Add up what each appliance draws and how long it runs:
– 12V compressor fridge: ~600 Wh/day
– Roof vent fan (8 hours): ~80 Wh
– LED lights (4 hours): ~40 Wh
– Laptop + phones: ~150 Wh
– Water pump (cycling): ~50 Wh
– Furnace fan (shoulder season, 2 hrs): ~100 Wh
– TV / entertainment: ~150 Wh
That’s roughly 1,150 Wh/day for a fairly typical 30-amp setup with no AC. For a longer-trip view of this calculation, see [how much solar you need to boondock for a week](https://rv.energy/how-much-solar-do-i-need-to-boondock-for-a-week/).
## Step 2: Translate watt-hours into panel wattage
A reasonable rule of thumb in real-world conditions (not lab spec sheets) is that each watt of solar produces about 3–4 watt-hours per day in summer and 1–2 Wh in winter. So 1,150 Wh of daily use divided by 3.5 = ~330W of panels needed just to break even on a sunny day.
For a margin of safety — clouds, partial shade, longer days indoors — multiply by 1.5 to 2x:
– Minimum: 400W
– Comfortable: 600W
– Future-proof: 800W
## Step 3: Match panels to battery bank
Solar doesn’t power your fridge directly — it refills your battery. A 200Ah lithium bank (~2,560 Wh usable) is the sweet spot for most 30-amp rigs. 400Ah lithium is overkill unless you’re stationary for long stretches or running AC at night. For a deeper look at pairing solar to that bank size, see our guide on [how many solar panels to charge a 200Ah lithium battery](https://rv.energy/how-many-solar-panels-to-charge-a-200ah-lithium-battery/).
The MPPT charge controller should be sized for your panel array, not your battery. A 40A controller comfortably handles ~600W on a 12V system; jump to 60A if you go beyond that.
## What you can’t do on a 30-amp solar setup
Even at 800W, rooftop solar will not run a 13,500 BTU air conditioner all afternoon — that needs more like 1,500–2,000W of panels plus a much larger battery. If AC off-grid is the goal, plan for a [50-amp fifth wheel sized solar system](https://rv.energy/how-much-solar-do-i-need-for-a-50-amp-fifth-wheel/) or accept that solar tops off batteries between generator runs.
## A quick gut-check before you buy
Run your actual numbers — your fridge, your climate, your camping style — through the calculator on the homepage. It’ll size the panels, battery, and charge controller for a 30-amp rig in about 60 seconds and tell you whether 400W is enough or whether you should stretch to 600W.
## Related guides
– [How many solar panels to charge a 200Ah lithium battery](https://rv.energy/how-many-solar-panels-to-charge-a-200ah-lithium-battery/)
– [How much solar do I need to boondock for a week?](https://rv.energy/how-much-solar-do-i-need-to-boondock-for-a-week/)
– [How much solar do I need for a 50-amp fifth wheel?](https://rv.energy/how-much-solar-do-i-need-for-a-50-amp-fifth-wheel/)
– [Best solar panel size for a full-time travel trailer](https://rv.energy/best-solar-panel-size-for-a-full-time-travel-trailer/)
**→ [Size your 30-amp RV solar system in under a minute](https://rv.energy/#calculator)**