Van Solar in Pacific Northwest

The Pacific Northwest has some of the lowest winter sun in North America. Grey, wet months mean a panel that makes 200 Wh on a July day can make a fraction of that in December. Full-time PNW builds should roughly double their array over the annual figure and plan a DC-DC charger from the alternator for long overcast stretches. Oversize the battery for autonomy, not the panels alone.

How to plan a build for Pacific Northwest

Plan the PNW in two halves. From April to September a 400–600 W array covers a normal build comfortably, and you can largely forget about charging. From November to February, solar becomes a trickle: at 1.5 peak sun hours a 600 W array averages under 700 Wh a day, which does not cover a fridge and a laptop. The realistic full-time answer is a DC-DC charger sized to your alternator, treated as the primary winter source with solar as the supplement, plus enough battery to ride out a week of rain. Campsite hookups are common and cheap here; budgeting for a few paid nights in midwinter is often cheaper than the panels you would need to avoid them.

Take a steady 1,500 Wh/day build. At Pacific Northwest's annual 3.8 peak sun hours that needs about 527 W of solar. In winter, with only 1.5 hours, the same load needs about 1334 W — that is the ×2.5 winter penalty in one number. Size your array for the season you actually travel, and let the battery cover the cloudy days.

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