How do you get off-grid power for a holiday home, retreat or campsite used mainly at weekends?

For off-grid power at a holiday home, an off-grid system with solar panels and a battery is usually the calmest and cheapest route. If the site is busy mainly at weekends, the panels fill the battery during the empty week. A generator, if any, is only back-up for dark winter weeks.

You arrive on Friday evening and check the generator fuel. All weekend you, your guests and the neighbours hear it run. Or the grid operator quoted more for a connection than you will ever use.

A meditation centre in Hechtel-Eksel runs this way on six existing panels and a classic home battery that charges on weekdays.

Do you need a grid connection to power a holiday home, retreat or campsite?

No. Choose the route that fits how and when the site is used. The real cost is everything around the kilowatt-hours.

A connection you use eight weekends is paid all year: Flanders charges capacity on at least 2.5 kW, even in empty months. The peak is short but high: a Friday group, an event kitchen, a full summer campsite.

At a hunting lodge in the woods of Gedinne, in Wallonia, only 180 V was left on a 3x230 V connection. A semi-off-grid system with a 46.2 kWh battery now supplies 3x400 V and uses the grid only as a charger. A generator covers power cuts.

Only a caravan fridge or lights on a seasonal pitch? A portable power station with a panel is enough.

A fixed system pays off from a chalet, retreat, sanitary block or site with guests. For lighting, signage or cameras without a building, see how to power lighting or cameras far from the grid.

How does an off-grid chalet or holiday home work?

The solar panels produce every day, also when nobody is there. During the week, all that power goes into the battery.

Its heart is an inverter-charger: it turns the panels' and battery's direct current into normal 230 V or 400 V and forms the local grid. At Hechtel-Eksel a hybrid Victron device does both jobs, with no new panels.

A stable and cottage in Kasterlee lie very far from the public grid. The owner wanted no generator running at every stay. Most use now comes straight from the panels; the surplus goes into the battery.

How big should the battery be for a weekend cabin or holiday home?

Size the battery on the weekend, the panels on the week. With five empty days, a weekend site often needs fewer panels and a smaller battery than a house used every day.

• The battery covers evening, night and a grey day of your stay, plus reserve.
• The inverter power follows your biggest simultaneous loads: kettle, coffee machine, water pump, sauna or electric heater. Heating or a car charger drains the battery fast and needs more power or a generator.
• Winter decides. In December, 1 kWp in East Flanders yields about 33 kWh in the whole month, against about 128 kWh in June (PVGIS).

Three off-grid systems we installed on sites without a grid connection show the range. Inverter power (kVA) is what the system delivers at once, battery size (kWh) what it stores. Tap a project for details.

When nobody is there for weeks, the panels keep charging. The app and the Victron VRM portal show charge, production and use per minute, hour or day. A low-battery alert warns you before you leave.

A Victron lithium (LFP) battery is rated for 2,500 cycles at 80% depth of discharge, far more than a weekend site uses in a year. Switch off a fridge or freezer that would run all week in an empty building.

Does a battery help a campsite or festival with high peaks?

Yes: a campsite with a connection has enough electricity, but its peak is expensive. In Flanders a busy summer weekend costs you all year. On low voltage the capacity tariff averages your highest monthly quarter-hour peak over 12 months.

Showers, kitchens and caravans create peaks in July and August that the quiet months do not reach. So one busy August weekend still raises the January bill. A battery behind the connection delivers the power above a limit you set, so the meter sees a lower peak.

Asked for a heavier connection for the busy season? Read what to do when a heavier connection is refused, or choose semi-off-grid, where the grid only charges the battery. The sums are in calculating the capacity tariff.

A festival can often run partly without a diesel generator. As on a building site, a battery takes the peaks and a smaller connection or generator only covers the average. A generator that runs all day for a few loads is the expensive part.

Our site battery article sizes on peak kW and daily kWh. A fixed event ground with buildings follows the approach above. Full event sizing: how big a battery you need for an event without diesel.

Which rules apply to an off-grid holiday home or retreat in Belgium?

A building without a grid connection is allowed. The safety rules of any electrical installation apply, plus a few steps:

• Notification: in Flanders, an island-mode installation (running without the grid) with an inverter from 800 VA is notified to the Vlaamse Nutsregulator.
• AREI inspection: the Belgian electrical code (AREI, RGIE in French) applies with or without a grid; an accredited body inspects a new installation before use.
• Permit and zoning: whether you may stay overnight or live in a chalet, holiday home or tiny house depends on zoning and permit, so ask your municipality first.