You are reading that very narrowly. The paragraph is simply pointing out that solar power is cheaper when built out in a centralised way because of:
* economies of scale for construction and maintenance
* higher utilisation. They don't spell it out exactly, but it is pretty clear fro m the context that, "lots of self-generated power will ultimately be wasted", is eluding to a wider geographic area needing more panels to satisfy all demand when each house has an independent system, rather than being grid tied.
I think this is true of a lot of things that are 'in our house' (or on our property). A fatuous hypothetical example might be a large central refrigerator shared between multiple properties.
The apartment building I live in has large central boilers for the hot water, to save space in the apartments. This benefitted the property developer, and is probably more energy efficient (although, just like our solar power example, transmission loss needs to be accounted for), but has downsides for the apartment residents.
A better example is private vehicle ownership, as opposed to public transport. It's a good example of something that has moved from a more centralised control to individual control, with benefits and downsides.
What's the downside of the central hot water? (Or heating.)
I've lived in buildings with this, and others (houses) without, and I much prefer the former. There's nothing I need to maintain, and the 'big' version seems to be more reliable than the single-house-sized heating equipment. The one time I remember the hot water being repaired, the janitor stuck up a note explaining that due to some sort of redundancy we'd still have hot water, but it would be less hot than it was supposed to be.
This wouldn’t be true in modern buildings, but in our case the hot water supply isn’t reticulated, and I’m at the ‘end of a (pipe) line’ so if no-one else sharing the same hot water pipe as me has run their hot water taps for a while, it can take 4 minute to get hot water in the shower.
This was bought up in a body corporate meeting several years ago. The cavities that the pipes run through are small enough that a reticulated system would be hard to retrofit. The suggested (tongue-in-cheek) solution was to “wait until you hear your neighbour showering before you have your shower.” Haha - thanks.
