Or, say, medium scale. I've taken away that communities of a couple hundred-thousands homes could now create their own grid, using wind/solar with batteries.

Islands are special use cases. Many non-US islands still run bunker fuel, some of the nastiest hydrocarbon fuel available. It is still eye-bleedingly expensive to burn that per kWh. Diesel gets you to ridiculous cost levels, and that's just fuel running costs. Add in personnel, and maintenance and repair, and solar looks good to a lot of island residents.

But self-sufficiency is a capital-intensive effort, and most residents cannot afford the up-front capital, nor have access to the credit necessary. That's yet another reason scaling up is the way to go for self-sufficiency.

> ...sometimes you end up with more power than you can use in the moment.

This is simply solved by co-generation, but it isn't easy: capital and/or credit availability drives this solution path. Excess power on an island can always be put to use somewhere, but it requires intensive capital equipment investments. Make potable water. Desalinate water. Push potable water uphill into a reservoir, then let it flow down through a hydroelectric generator at a minimum constant flow rate; constantly moving the water up and down hill keeps mosquitoes from settling in it. Many islands are in tropical zones, and there are always chilling needs: chill sea water in ocean-side reservoirs to drive central chillers. Even with efficient reuse and recycling, there will still be unreusable, unrecyclable trash: pull the surplus energy to drive a plasma arc-based garbage gasification plant (which generates more energy). Still more energy to use? Drive automated excavation machines with it, building out more reservoir capacity.

> Other than the fruit trees dotting the property...little else has taken root.

Permaculture techniques might assist here.

> ...the utility is offsetting some panel owners’ bills for their (less efficient) solar power...

This will take time (decades) before building construction habits change to regularly accommodate panels. Anywhere there is more climactic heat than desired for comfort levels, panels can be blocking the solar irradiation, but we don't have commonly-accepted construction idioms for moving panels to where they are needed around a building, and everyone ad hocs their own. I'd prefer to see people continue to use panels for the secondary and tertiary benefits, despite the reduced efficiency compared to utility-scale installations, for as long as real estate asset valuation remains high.

Yup. Diesel is so expensive, I don't understand why they are making 2030 plans. Why not 2018 plans? Solar panels are now about 40c / installed watt or less. They will have trouble getting much below that with even Chinese panel manufacturers barely breaking even. Interest rates are still very low.

Just get everyone involved & roll that solar out. Not a biggie. The savings will be immediate over burning diesel to generate electricity.

All your ideas were spot on & good for using excess energy.

Heck they can even mine some bitcoin if they have extra energy.

Much smaller than that is viable: https://building-microgrid.lbl.gov/isle-eigg

.. but generally the larger your grid the better.

But I guess there is some upper bound of connected nodes, or covered grid area, where it makes sense to break the grid up into sub grids, and make those sub grids self-sustainable? E.g. voltage losses over huge distances would force you to transmit with high voltage to faraway subgrids, and require additional transformer stations; not to speak of the line losses. I think you could eliminate those by giving each node cluster (residential area) its own closed grid. Perhaps emergency needs (like a rock concert in your neighborhood) could someday be covered by long distance laser or EM transmission from other grids, without using a landline that makes power management so difficult (because when interconnected, all grids would have to coordinate their combined consumption).

> long distance laser or EM transmission

This is either impractical, or a literal death ray.