This article doesn't explain the link to solar. What I'm seeing is:

1. Some Dutch homes seem to have X amps of service

2. Some of those want Y amps, where Y > X

3. That upgrade is taking time and the servicers are asking for patience

I don't see the link to solar?

Central control of heat pumps sounds like a dystopian nightmare. I don't want to give somebody outside my house the ability to shut off my heating or cooling.

The real problem is that the price of electricity isn't high enough. When supply is running out, raise the price so supply and demand can find equilibrium, then invest the new revenue into increasing capacity.