I have figured out when Studio Display irritatingly buzzes and how to stop it

There's plenty of questions on the forums (and all around the internet) about Studio Display buzzing, squeeching, humming, or otherwise being annoying.

I have figured it out, at least for my house and my setup.

Essentially, when there's lots of power surging through the house, and MacBook is plugged into Studio Display with the built in cable, the display will start to make noise.

Lots of power, for me, means when my solar production is high, and there's 5-6kW going through the house's veins, either charging my car or being exported. As soon as there's a cloud, and there isn't lots of power running through the house (because car charges only on solar, stops charging when Wattage drops below 1.4), the display stops buzzing. Of course, if I do charge my car through grid power, same thing happens. If there's lots of power, no matter how it comes into the house, the display will buzz.

In order to resolve this, I simply charge my MacBook with its regular MagSafe charger, and have the display's cable be just image cable effectively. This then doesn't put any strain on the power supply of the display. So my MacBook is plugged through two cables, not through one, I can live with that.

Of course, I don't know exactly why this happens, I am not an electrician. People speculate that Display's PSU is poorly shielded or something, but I think we will never know.

All I know is that I've solved the problem for myself. I hope this will work for you as well.