Avoiding for a moment the problem of glass walls that need to be several feet thick, I would like to propose an alternative method for growing greenhouses: make them move with the sun.

Using circumlunar electric rail transport, with periodic solar panels set up as sun shades over the track to provide power and day/night cycles seems like the most logical setup. Glass walls can be replaced with fiber optic cables, in an idea I will post separately.

Those who want details can stay tuned for the grueling mathematical examination of the concept which I am writing below:

The moon has a synodic period (from new moon to new moon) every 29.5305882 days, or once every 708.7341168 hours, whichever comes first.

The moon's diameter is 3476 km, and by judicial use of the concept of Pi and radii, I can therefore calculate that the moon's circumference should be about 10914.64 km.

This means that the terminator of the moon (no, not Arnold... the line between dark and light) moves around the equator at a speed of approximately 15.4 kilometers per hour as the eagle flies.

Of course, rail transport would not be moving in a perfectly straight line. The tracks would need to curve a bit here and ther to get around mountains. I understand that surface routes tend to be about three times longer than air travel for this reason, and the vehicle would therefore need an average speed of about 46.2 km/hr.

As with most rail transport, it would also need to stop occasionally, to unload cargo, undergo maintenance and repairs, and possibly to accept commuters on one garden-like leg of their commute (return trips would be provided by non-greenhouse vehicles, for obvious reasons.) This down time may account for as much as half of a vehicl'es moving life, and therefore, the trains would likely need a maximum speed of twice their average speed, meaning that the trains would need to be capable of traveling at 92.4 km/hr.

Those of us with the sad need to see things in miles per hour will be pleased to know that this Lunar Green Line will apparently need a top speed of less than 60 miles per hour That's a little slow for most industrial rail cars, and the load on the trucks could be significant, due to needing water, and soil, or hydroponic grow mediums, but it's certainly nothing compared to Japanese bullet trains, and with lower gravity, and no atmosphere to produce drag, I suspect this moderate freeway speed train should be wholly feasable at the equator.

Since the equator is the widest part of the earth, such a system would be even easier to setup at other locations, and therefore, this idea could be applied to any locale on the moon. Food production no longer needs to be the sole domain of polar colonies, and huge batteries will not be required.