I don't think that's correct. It only shows renewable sources, and of those solar and wind are (obviously) the vast majority here in NL. But it's not even possible to enable showing coal and nuclear on that site, even though you can't convince me that they are literally not operating at all on a relatively cloudy day like this.

Don't get me wrong, I wouldn't be surprised if renewables were a majority of the grid these days. It's just that this dashboard contains insufficient information to conclude that.