Method of storing energy on the Moon

[Al_]

TL;DR

This article: https://phys.org/news/2026-01-lunar-nights-martian-storms-batteries.html says batteries are problematic in space. I propose a flywheel.

Batteries bad

The article linked above says batteries are problematic in space. I propose a flywheel, which is suited to the Lunar environment. 1) It is in vacuum already. 2) Magnetic suspension is less demanding in 1/6 gravity. 3) Superconductors need very low temperatures which are easily available 4) Craters provide ready-made disintegration safety containers 5) Local resources can be used to manufacture parts on the moon, e.g. spun basalt fiber has high tensile strength. 6) The device's performance will not degrade as quickly as a battery 7) It can store power for the duration of the Lunar night with minimal loss

 

[jrmichler]

Some points to consider before you get too excited:

1) Thermal cycling also kills motor/generators. I once headed a motor reliability project. The primary cause of failure was thermal cycling. If the energy storage is underground or inside a thermally insulated structure, thermal cycling will be minimal.

2) Estimate the cost to store a realistic amount of energy. A starting assumption is that you need to store enough to supply 100 kW for 3 weeks. That's 50 megawatt-hours. Calculate the mass and cost of batteries to store that much, then the mass and cost of a flywheel energy storage system. Note that the cost is the cost of a system installed and running on the moon. And that the mass is the system mass, not just the mass of the spinning rotor or battery cells.

3) Any concept that requires manufacturing on another planet must include the cost, energy requirements, and mass of the manufacturing plant that is shipped to that planet.

It is not a trivial problem.

 

[Rive]

Superconductors need very low temperatures which are easily available

One of the problems is thermal cycling. Superconductors are just about a different temperature window than batteries, but it's still a window.

Local resources can be used to manufacture parts on the moon, e.g. spun basalt fiber has high tensile strength.

I can assure you that local manufacturing of that kind of inertial mass would be a real nightmare.

I won't say that it's not possible or that there are no circumstances what would make this practical, but not in any close future.