Well this is what the article covers, Grid Forming Inverters, I.e. inverters that have the ability to behave like they’ve got inertia, and where the feedback lo

Well this is what the article covers, Grid Forming Inverters, I.e. inverters that have the ability to behave like they’ve got inertia, and where the feedback loop between frequency and power output is tight enough they will naturally migrate to a stable grid frequency, rather than just bouncing around all over the place like normal Grid Following Inverts do if there isn’t enough spinning inertia in the system. So even in world where all power sources are coupled to the grid via inverters, it’s still possible to use the grid frequency as communication channel. Side channels that exist physically outside the grid will never be reliable and ubiquitous enough to replace grid frequency, for grid stability you need a feedback loop measured in nanoseconds to avoid scary oscillations in load and supply, that feedback loop needs to be faster than a microcontroller can manage, hence the reason why Grid Forming Inverters are more complex than normal Grid Following Inverters. After all the system you’re trying to monitor and keep stable naturally communicates at the speed of light, so it really isn’t possible to use digital systems to keep it stable. You need some sort of analog inertia (whether that’s spinning rotors, or clever analogue electronics doesn’t really matter) to handle the high frequency changes, and damp them enough for digital electronics to deal with the longer term drift. Also it’s not just suppliers that coordinate via frequency, it’s also loads. Anyone out there running a large semi-continuous, but interruptible loads (e.g. water pumps, large arc furnaces, heating systems, bulk EV charging etc) can usually get a discount on their energy prices, in exchange for voluntarily disconnecting their load if the grid frequency drops too far, allowing the grid to shed the least sensitive loads first, before it’s starts forcefully disconnecting more sensitive loads. > Capacitors do the same for DC. They are also more efficient and reliable. I don’t know who told you that, but capacitors aren’t even vaguely close to reliable compared to a spinning turbine. Not once you consider how many capacitors you would need to store an equivalent amount of energy as a spinning turbine. Super capacitors top out at about 4 Wh/kg, and can get up to 10 Wh/kg if you’re using hybrid capacitors (which basically a mix of a battery and capacitor). A flywheel energy storage systems are around 100Wh/kg. So at least one order of magnitude more energy per kg. So you need a lot of capacitors to replace the energy storage of a turbine. Once you’ve got that many very expensive capacitors linked up with the needed control electronics, I doubt it’s anywhere near as reliable (or cost effective) as a big spinning chunk of steel.