Space Odyssey: can moon power answer the earth’s energy needs?

Giant solar belt around moon could meet all of humanity’s energy needs by 2030, say Japanese inventors

Japan luna ring 466

By Ed King

Japanese scientists believe they have discovered the secret to providing the earth with clean energy: build a giant solar power station on the moon.

The plans, published on the Shimzu Corporation website, say the energy could be sent back to giant receivers on planet earth’s oceans via lasers and microwaves.

A 400km wide solar belt constructed on the moon could produce energy equal to 17 billion tonnes of oil equivalent (TOE).

This is equal to the amount of energy the International Energy Agency believes will be consumed by 2030.

Shimzu say pilot demonstrations could be carried out on the moon in the 2020s, with construction of the Lunar Ring by astronauts and robots to start in the 2030s.

The plans add that “Lunar resources will be used to the fullest extent possible in constructing the Solar Belt” to save on rocket costs.

Perhaps unsurprisingly, experts appear slightly sceptical of the plans. Dr Ned Ekins-Daukes, a senior lecturer in Physics at Imperial College, London points out the costs of launching materials into space would be significant, around £50,000/kg.

I’ve attached his response to my questions below:

-On the first point, it would be easier and cheaper to build a ring of solar panels around the Earth rather than the moon which would also give 24/7 power.  An entire mining and manufacturing economy would be required on the moon for this to be possible, this exists today on Earth.  A covering a small fraction of the world’s deserts would power the entire planet.  This is the vision of the Desertec project.

-On the second point, clouds and night time clearly reduce the power output from solar panels, but even on the moon there is day and night.  The term “dark side of the moon” is misleading, the moon rotates so that one side is always facing the Earth, but both sides experience day and night.   While clouds do reduce the output of solar panels, they do not reduce it to zero and were solar power manufactured and connected on Earth at the scale envisaged by the Lunar Ring project then there would be an effective balancing of supply and demand over the planet.

-Thirdly, one of the key benefits of solar power is that it is distributed.  Power can be generated and consumed locally, whether in individual homes or within districts.  Having the moon beaming power down to Earth eliminates this advantage and establishes some hazardous areas where a very large quantity of power (microwave or laser) would be delivered to the Earth’s surface.

This isn’t the first innovative idea Shimzu have come up with.

Other concepts include low carbon floating cities that would use ocean waste as power, and a space hotel, closely resembling the ship used in Arthur C Clarke’s 2001AD.

City in the sky

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