Off-Grid Van Living: The Complete Electrical & Systems Guide
What does it actually take to live full-time off-grid in a van? We break down every system — electrical, water, heating, and ventilation — with real specification numbers.
Off-grid van living is achievable. Tens of thousands of people do it full-time across Europe. What separates comfortable off-grid living from miserable off-grid living is almost entirely a function of what's built into the van before you leave.
The electrical system: the heart of everything
Every other system depends on your electrical specification. Get this right and almost everything else follows.
For part-time use (weekends and holidays): 200Ah lithium, 200W solar, B2B charger from alternator. This will comfortably run a compressor fridge, lighting, phone charging, and a laptop for 3–5 days without sunlight.
For full-time use: 400Ah minimum, preferably 500–600Ah. 400W+ solar. Shore power capability. Alternator charging with a proper B2B charger rated for your alternator output. At this specification you have genuine resilience — a week of overcast skies will not leave you managing battery anxiety.
The battery chemistry: lithium (LiFePO4) is now the correct choice for van conversions. The weight savings, depth of discharge (80–90% vs 50% for AGM), and cycle life (3,000–5,000 cycles) justify the higher upfront cost within 2–3 years of regular use for most users.
Solar: real numbers
Marketing materials inflate solar output. A "400W solar system" will produce 400W only in perfect direct sunlight at optimal panel temperature. Real-world UK production in summer: 150–250Wh per 100W of panel per day. In winter: 30–80Wh per 100W.
This matters for system design. If you're full-timing in the UK in winter, you need either significantly more panel area, shore power access, or to accept that you'll charge primarily from alternator driving.
Heating: the system that matters most
In the UK climate, heating is the most important system in the van. The options:
Diesel air heater (Webasto, Espar, Chinese units): Combustion air pulled from outside, exhaust vented outside. Heats the cabin quickly. Proven technology. Global parts availability. Noisy at startup. Best for: most builds.
Hydronic heating (Webasto Thermo Top, Eberspacher Hydronic): Liquid-coolant system that provides both cabin heat via radiators and hot water via a calorifier. Quieter, more even heat distribution, and integrated water heating. Significantly more expensive and complex to install. Best for: premium builds where hot water integration and silent operation matter.
Propane heating: We don't recommend it for sealed vans. The carbon monoxide risk is real. The condensation output is significant. Use it only with proper ventilation management, never while sleeping.
Water systems
A van water system has four elements: tank, pump, filtration, and waste.
Tank: 50–100L for most builds. Fixed tanks under the floor or in the garage are more efficient than portable jerricans. Insulate the tank and all exposed pipework if you're operating in sub-zero temperatures.
Pump: a 12V diaphragm pump (SHURflo, Jabsco) gives adequate pressure for a kitchen tap and shower. Install an accumulator tank to reduce pump cycling and extend pump life.
Hot water: a calorifier (water heater exchanging with the diesel heater circuit) or an on-demand diesel water heater (Wallas, Webasto). Electric immersion heaters via shore power are fine as supplementary heating but should not be the primary off-grid hot water source.
Filtration: a basic under-sink filter removes sediment and improves taste. Useful when filling from variable sources.
Ventilation: often neglected
Condensation in vans comes primarily from breathing and cooking. The fix is ventilation, not more vapour barrier.
A quality roof vent — the Maxxair Deluxe or Fan-Tastic are the standards — running on low overnight will remove the moisture a sleeping adult generates. Two vents, one front and one rear, create cross-ventilation in warmer months.
If you're cooking in the van, run the vent on extract. One pot of pasta produces approximately 600ml of water vapour. That moisture will find the coldest surface in your van and condense there.
Putting it together
There is no universal specification. The right system depends on how you use the van, where you travel, and how long you're away at a stretch. What doesn't change is the hierarchy: electrical first, heating second, water third, ventilation throughout.
Get the systems right and the van becomes infrastructure — something you live in without thinking about. Get them wrong and the van becomes a project that manages you.