Hacker News Reader

Comment by photochemsyn | Hacker News Reader

Solar PV linked to battery storage is the obvious energy source for a moonbase. All reactors require coolant circulation and water is going to be among the most valuable commodities on the moon, not something you want to circulate through a reactor (where you inevitably get tritium formation, making the water unsuitable for other uses).

Maybe you could use helium or liquid sodium metal as the primary coolant, but then you still need to generate electricty via secondary water coolant loop that runs a steam-powered turbine. Really not plausible on the moon.

View on HN

> Solar PV linked to battery storage is the obvious energy source for a moonbase

It's not serious with chemical propulsion and the Moon's day/night cycle. Put another way, if one team uses nukes and is, as a result, power unconstrained, while the other spends all its energy launching solar panels and batteries to keep life support online, it's obvious who's going to be doing any science.

> All reactors require coolant circulation and water is going to be among the most valuable commodities on the moon

Sodium and sterling, no water [1]. There is a reason even NASA is only seriously considering nuclear power [2].

[1] https://www.nasa.gov/directorates/stmd/tech-demo-missions-pr...

[2] https://www.nasa.gov/tdm/fission-surface-power/

Solar PV battery combo is just a giant spatial transmission line system for a fusion reactor. For high density applications, fission and/or fusion make more sense.

It's just that we're close enough to the Sun, and that a lot of us are living in low-density residences.

Solar ray density reduces to half of what we get on Earth on Mars our closest outer planet, simply from inverse square law. And deep space people always said it goes down so fast a space nuke is a hard requirement for Jupiter and beyond. There might be ways to make it work on Moon, but PV plus battery is just rural inner planets thing, not the way forward or anything. It's just temporary hype technology.

You'll need a massive amount of batteries for solar night. People severely over-estimate battery storage.

Even on earth, giant grid-scale storage system are not able to supply all the power for region they serve alone for more than some 4 or 6 hours. In the moon, they would have to supply power for some two weeks.

Battery storage is not a real solution on earth, it is even less plausible in the moon.

You'll need an insane amount of battery storage, since the moon only rotates once per month and you'll need to power through a long period of no sunlight.

Or just very long power lines and multiple solar stations, it's not like the moon is impossible large. But that would be harder than a singular location using nuclear fuel, it's true.

Or alternatively, for polar bases, very tall panels, which would be able to be in permanent sunlight.

> very tall panels, which would be able to be in permanent sunlight

Or normal panels on the rim of Shackleton [1]. (You'd still want to bootstrap with fission.)

[1] https://en.wikipedia.org/wiki/Shackleton_(crater)#Potential_...

A belt of solar panels encircling the moon would solve that problem though perhaps a bit ambitious at present.

Reply on news.ycombinator.com