"One way to purchase sunlight is through a solar easement. You buy from a house owner a binding agreement that he will not add anything to his house that would block the passage of sunlight to yours." This is sort of a crappy summary, because several of these laws are more about trees than they are about house modifications, but I don't know precisely which ones he looked at when he was researching this book nor exactly what the statutes said at the time. And one thing I know about researching what laws _used_ to say is that it's often of hard to track down.
"There is another approach and it avoids compensation. The model for this is New Mexico's statute... These statutes invoke the who-was-first principle of Western water-rights law, or Doctrine of Prior Appropriation. The statutes provide that the first man to install a solar collector has first call on the sun and will continue to."
Again, not a terrific summary: you have to file for it and that's not a trivial process and you have to define your path/angle in some detail.
"It is quite a conferral. ... [an owner] could seriously impede subsequent development and impair their property rights."
"There is not enough experience yet for firm conclusions, but I would guess that the easement approach will prove sound, if limited, and that the prior-appropriation approach will not. I would also guess that the easement approach will prove most useful in conserving sunlight for sunlight's sake and that its main application will be in cities."
In order to _get_ an easement, you have to negotiate in a binding, legal, file with the recorder sort of way, with any neighbors. Whyte thinks someone is going to do this to guarantee that they have sunlight, not for power, but just for sunlight, and to do this _in advance_ of someone directly threatening that access (because when the developer owns the property and plans to build believe me you won't be able to buy the easement then). The only thing that could convince someone to go through the hassle of negotiating for and filing the easement is that they are planning to spend tens of thousands of dollars on a solar installation and they don't want the neighbors trees to block it in five years, which they predictably _will do_, but which you can pay the neighbors to agree to cut down if you plan ahead of time.
New Mexico's approach seems to be holding up fine, and the current energy environment suggests that's not going to change.
I think this is actually a classic example of bias (not the "he/his" for property owner, altho that is grating, too). If you haven't lived with prior appropriation rules, they just don't seem real. But if you _have_ lived with prior appropriation rules, you know just how inflexible they can be, particularly since they only tend to get invoked when the pressure is on.