Power connection - empty conduit to garage / e-car charging station

Hello everyone,

we have a garage about 30 meters away from our house, accessible via a shared path. (I have attached an overview image to the post) The shared path will be renovated soon, and we want to supply our garage with electricity. Currently planned is to lay a normal power cable (outdoor area rated at 0.03A).

To have the option in the future to lay another cable, the idea was whether it would be better to lay the cable (also for protection) directly in a suitably large empty conduit. What type of conduit and diameter would be best here? The suggestion from the external builder was a PE pipe to avoid problematic bends when pulling cables later?

It would be conceivable, for example, to have an electric car charging station, which requires a suitable cable for high power, or should the high power cable be laid immediately as well? Does anyone have a recommendation for which high power cable / type / conductor size would be best to use here? Is there any reason against laying it as preparation without connecting it?

Many thanks in advance for all the answers!

Just dealt with the topic myself, even though it wasn’t quite that long. I installed a 5x10mm2 right from the start. That allows me to easily charge at 11kW (the cross-section is actually oversized, 5x6mm2 would have sufficed). But maybe a second charging point will be added at some point. During the installation of the Wallbox (Tesla Wallconnector), it became clear that more than 10mm2 wiring definitely wouldn’t be fun; it was already at the limit.

I would also directly size it sufficiently and put in as much as makes sense right away.

Otherwise, you'll be messing around again in 5 or 10 years. You don't just open up a sidewalk for a small amount of money.

Lay an NYY-J cable as 5-core with 6 or 10 mm2. For the conduit, I recommend using at least a 50 mm, preferably 63 mm or 110 mm. No KG conduit because it is often mistaken for a channel pipe later on.

We have an empty conduit with a diameter of 100/110 from the cellar to the garage. This is directly connected to the [Mehrspartenhauseinführung] and sealed. We have a 5x10mm2 cable and a "normal" 3x5mm2 for lighting and the gate, etc.

Ideally, lay a cable right away. Over this length, a cable with the correct cross-section can no longer be pulled into an empty conduit using household methods.

At about 30m length, roughly estimated to 35m effective cable length, a 10mm^2 is just enough for 2x11kw or a 22kw charger, calculated with 1% voltage drop. So 10 square millimeters is the minimum cross-section I would start with. This will then be connected to a sub-distribution board and not directly to the wallbox.

Please also pay attention to the local TAB (have it checked) and have the dimensioning planned by a professional. You can also pull the cable yourself if it's not frost.