What does bifacial mean here?

The panel has cells that can collect light on both faces. The back side adds output when it faces a bright reflective surface such as snow, sand or a white roof.

Do I need a special charge controller?

No special type is required, but the controller or power station input must accept the panel's voltage and current. Check the panel's specs against your device's input limits.

Is N-type better than standard panels?

N-type cells typically lose less output as they heat up and degrade more slowly than older P-type cells. The practical gain is modest but real in hot conditions.

Can I mount it on a roof or a vehicle?

It is a rigid panel suited to flat or tilted mounting, including van roofs. Leave air gap behind it for cooling and use proper mounts for wind loads.

Which wattage should I pick?

Choose 100W for small, portable setups and 200W when you need more daily charging for a battery bank or power station. Match total panel wattage to your battery and controller.