An artificial glacier growing in the desert (2017)

This is IMHO very much an example of "permaculture"-ish thinking, at least in the original spirit of the philosophy.*

Studying and leveraging natural dynamics (e.g. the role the glaciers previously played), paying attention to energetics (in the physical sense), avoiding waste by clever system design (e.g. harvesting the gravitational potential energy upstream that would otherwise be dissipated, volume/surface ratio, etc).

For those who like this kind of thing, ref. also the returns on swaling dry areas, Geoff Lawton's "Greening the Desert" work, Alan Savory's surprising conclusions about the restorative value of animals in Africa, etc.

Anyhow, what a great story. Thanks to the OP for the point-out!

* I use original in terms of the older original work by Bill Mollison and Masanobu Fukuoka, who had a more general systems take on ethics. More modern interpretations tend to be more political and also come to some more limiting conclusions.

ETA examples and fix grammar

I'm not sure that's true. I think they're talking about how much they're in the Sun and I think I can construct a single counter example, r=2 h=1 for the cone, r=1 for the sphere should be the same volume. For light at 90 degrees the area in the sun would be 2m^2 for the cone and pi m^2 for the sphere.

That's not a perfect calculation so I don't know where the limits are here but I don't think they're talking strictly about surface area.

At the stated 150,000$ to irrigate 25 acres this is in no way viable.

At a guess this is generally viewed locally as rather pointless as you can store far more water with a simple earthen dam. Basically, the hard part is having water in the first place not storage.

In terms of efficiency, spraying water into dry winter air likely resulted in quite a lot of evaporation. Further 150,000 liters of water sounds like a lot but it’s about 1.5 inch of water across an acre. Which is why you would need dozens if not hundreds of them per farm.

The reason this works is that it is only filling the gap between the end of winter and when the glacier melt catches up. So you freeze water over the winter, and then it melts in the spring to feed your newly planted crops. By late spring the ice is all melted but that's fine because your normal source of water is active again.