Plan solar for places the grid does not reach: cabins, campervans, boats and garden offices. These tools size every part of a stand-alone system from your daily energy use.
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Off-grid systems must be sized for the worst month, not the average one. In northern Europe winter sun can be a small fraction of summer sun, so a system that runs happily in July may fall short in December unless you add panels, battery or a backup charging source.
Start with the off-grid solar calculator for fixed sites, the campervan calculator for 12 V vehicle systems, and the power station runtime calculator for portable battery units.
All off-grid & van solar calculators
Frequently Asked Questions
How do I size an off-grid solar system?
Add up your daily watt-hours, divide by the worst month's peak sun hours and a performance factor to get panel watts, then multiply daily use by your days of autonomy and divide by usable depth of discharge to size the battery.
How much solar do I need for a campervan?
It depends on your 12 V loads and the season. A compressor fridge, lights, a fan and phone charging can use several hundred watt-hours a day, which a modest roof panel covers in summer but not in winter without driving or hook-up charging.
How long will a portable power station run a device?
Multiply the capacity in Wh by the usable share and the inverter efficiency, then divide by the device's watts. A 1,000 Wh unit running a 100 W load through an 85% efficient inverter lasts roughly 8 hours.
Checked October 2026 by the Solaxyra Editorial Team. Read how we build and check our tools in our editorial policy.