Of course this varies quite a bit, but I would argue that people tend to want to live in sunnier places (population is generally higher near the equator than near the poles, but of course this is limited by landmass distribution too). So that means that solar generally works where the people are, hence the effectiveness of rooftop solar. While residential solar involves a lot of redundancy (of inverters and other components), rooftop solar on massive warehouses, factories, supermarkets, etc. is much more effective (pair this with electric delivery vehicles for extra efficiency). I don't know why we aren't seeing more of it. Certainly in densely populated urban areas solar doesn't work so well, since a skyscraper doesn't have much roof space compared to the amount of people in the building, and due to shading from other buildings.
Good points here, it varies a lot depending on what you are trying to accomplish. As you said, I'm mainly thinking at the municipality scale, and thinking about points of community aggregation, such as hospitals, schools, supermarkets, etc. I see your point about a factory having an unpredictable production schedule, but both Tesla and BMW are making it work. Tesla's gigafactory 1 in Nevada uses a combination of solar, wind, and geothermal, and was carefully sited to be able to make those three work in tandem. Retrofitting existing factories in less ideal locations will of course be much harder, and are more likely to continue to rely on the grid.
Milligrid is a new term for me, I like it. I'll research that more.
I'll admit that I have a kneejerk reaction to any solution that involves burning more fossil fuels, but this video on the future of turbine powered range extenders has gotten me to expand my view a bit. At least in the near term, this seems like a promising technology to get us through the next few decades (as we wait for battery tech to improve). See what you think:
(also check out turbine range extended electric aviation...also looks promising)
I'll have to look for that one. There's also a similar approach of using bladders of compressed air (in mineshafts or natural salt domes) as an energy storage system. Makes a lot of sense, and very safe as well.
