This will hopefully be something like district heating, so a central heat pump that distributes hot water. I don’t think hydrogen in on the table. They could add a flow battery to capture more solar energy locally but I don’t think that’ll be on the cards early on.
But in reality it’ll probably be a heat pump per home and a big energy bill for us. Our street was built over 50 years ago when natural gas was plenty and cheap so insulation wasn’t much of a concern. We’ve added insulation under the floors and in the walls, but it’s never going to be as well insulated as a modern home.