Van Solar in United Kingdom
The UK has low sun for much of the year and very low winter sun — solar alone will not keep a full-time van charged from November to February. Size panels for the shoulder seasons, lean on campsite hookups and a DC-DC charger in winter, and build a generous battery so a few sunless days do not strand you. Flat, horizontal roof panels lose even more in low winter sun angles.
Take a steady 1,500 Wh/day build. At United Kingdom's annual 2.5 peak sun hours that needs about 800 W of solar. In winter, with only 0.8 hours, the same load needs about 2500 W — that is the ×3.1 winter penalty in one number. Size your array for the season you actually travel, and let the battery cover the cloudy days.
The calculator below is prefilled with United Kingdom sun. Add your loads and toggle winter to see your own numbers.
Quick start with a profile:
Your daily loads
Add each device with its watts and hours per day.
No loads yet. Add your fridge to start, or pick a profile above.
Solar array
—
Add loads to size your array.
Show the math
Battery bank
—
Show the math
Charge controller (MPPT)
—
Show the math
Inverter
—
Show the math
Battery-to-inverter wire & fuse
—
Show the math
Estimated cost
—
Budget street price → premium brands.