We are using Philips Hue lights in our house and I extended the system so that it reaches into the shed where my setup is located - this works via a mesh network that is created by the individual lights in the Hue system (see it as: "one light can send signals to other lights, so adding a light extends the range"). The Hue system also offers power switches that can be remotely turned ON and OFF (and I believe they have a maximum rating of 230V/2000 watt), I use one of those to turn ON/OFF my mount.
It's convenient if you already have a Hue system in place, it's pricy if you need to set this up from scratch since you'll also need a Hue bridge and you'll want to connect it to a Wi-Fi network etc. One remark: they are for indoor use, not sure if they have these available for outdoor use.
Next to this, I work for a QA/Testing company and for some of the services that we offer, we install a server rack that also includes a remotely switchable power supply with multiple outlets (you can just access the equipment via a web page). They are of the Anel brand. I haven't used them much, but when I needed them to switch power they always did.