Japan's Bold Lunar Ring Plan Would Turn the Moon into a 24/7 Power Station

by Aaron Leong — Tuesday, May 05, 2026, 10:11 AM EDT

One of the "Big Five" general contracting and engineering firms in Japan has revived one of the most audacious energy ideas ever sketched: wrapping the Moon’s equator in a giant belt of solar panels and beaming the power back to Earth via lasers and microwaves. So instead of building solar farms on Earth, why not build where the sunlight never stops?

luna ring model — *That's no moon... it's a power station.*

Shimizu Corporation calls the concept Luna Ring (not to be mistaken for the smartring of the same name), and its own materials describe a solar belt that would stretch for about 11,000 kilometers (6.835 miles) around the moon's equator, with widths ranging from a few kilometers to as much as 400 kilometers. Because the Moon has no atmosphere, no clouds, and no day-night cycle in the way Earth does, the system can harvest near-continuous sunlight and turn it into electricity around the clock. According to Shimizu, that electricity would be routed to a transmission base on the Earth-facing side of the Moon and converted into microwave or laser beams for delivery to ground receiving stations, or rectennas, on Earth.

The scale of this project is indeed extreme. Even a ring 100km (62mi) wide would amount to roughly 1.1 million square kilometers of solar infrastructure. Shimizu’s older presentations went further, suggesting the concept could eventually deliver enough energy to alter the balance of global power generation, though it has never been framed as a near-term engineering project.

luna method — *Cables carry power from the solar cells to Earth-facing side. Microwaves and lasers beam it to ground stations. (Credit: Shimizu Corp)*

And of course, the proposal faces significant skepticism regarding its economic and logistical viability. Even though the physics of space-based solar power are sound, the costs of transporting initial machinery to the Moon and maintaining a complex infrastructure 238,000 miles away may outweigh the benefits. Critics argue that the rapid decline in the cost of Earth-based renewables and battery storage makes a lunar-scale intervention an answer to a problem nobody really has.

Still, the Luna Ring keeps resurfacing because it compresses several powerful dreams into one: energy abundance, robotic construction, lunar industry, and a cleaner replacement for fossil fuels. The company has described a future in which lunar sand becomes concrete, glass fiber, and even structural materials used on-site (wait, that sounds familiar), with robots doing much of the building under Earth-based control.