Freeing home energy gear from vendor lock-in. Matter 1.4 adds some big, expensive gear to its list of device types and control powers, and not a moment too soon. Solar inverters and arrays, battery storage systems, heat pumps, and water heaters join the list.

Yeah I seriously doubt solar inverter providers will sign up to this. Here's what QCells said when I asked them about an API:

I’m sure it is possible and we’re in discussions with some providers over opening up to their requirements, but it’s not something we’d offer to individuals unfortunately.

They view control of their "virtual power plants" as a commercial asset and they don't want to give it away for free.

Don't buy a QCells solar inverter btw. I should have done more research! I believe GivEnergy are less stuck in the 80s but don't quote me on that.