Solar Power Satellites

solar power satelite

I love space. I count myself blessed to have grown up with family members who encouraged in me a strong interest in the sciences. I feel they would be quite happy to know that that interest has only grown stronger as time went on. Now I spend most of my free time researching topics both science-fiction and science-fact so that I can write my own stories to hopefully inspire some future generation of dreamers to look up to the stars.

Of course, that doesn’t mean I believe that an enterprise in outer space can be fuelled solely by hopes and dreams.

And what better way than through the Energy Sector?

Without a doubt, the energy sector is the foundation upon which civilisation is built. We know our current reliance on fossil fuels can’t last forever.

While solar power has done good work so far, and is getting better as the years go on, it is limited by certain conditions here on Earth. This is where the idea of solar power satellites came in.

What are solar power satellites?

Solar power satellites are a method of collecting solar energy from space for earthside purposes. The satellites are equipped with solar panels that can freely collect energy from the sun without interference from Earth’s atmosphere.

The collected energy is converted into microwaves and then beamed down to dedicated collector facilities on Earth.

The earliest known example is from a short story written in 1941 by the legendary science-fiction writer Isaac Asimov. In his short story, “Reason”, a space station transmits energy collected from the Sun to various planets using microwave beams.

Several decades later, amid the Space Race, several proposals were drawn for putting up solar power satellites by the United States.

Advantages of space-based solar power

The chief advantage of space-based solar power is that collecting surfaces could receive far more intense sunlight, owing to the lack of obstructions such as atmospheric gasses, clouds, dust, and other weather events. Consequently, the intensity in orbit is approximately 144% of the maximum attainable intensity on Earth’s surface.

Space-based solar power generates forty times more than solar panels and brings almost zero percent of hazardous waste to our environment. It also allows for electricity to be generated continuously, twenty-four hours a day, 99% of the year.

A satellite could be in Earth’s shadow a maximum of only 72 minutes per night at the spring and fall equinoxes at local midnight. Orbiting satellites can be exposed to a consistently high degree of solar radiation, generally for 24 hours per day, whereas earth surface solar panels currently collect power for an average of 29% of the day.


The main drawback holding us back from developing space-based solar power is the cost associated with both launching and maintaining the satellite. Both come from the expense of transporting mass up Earth’s gravity well.

Space debris is also a major hazard to large objects in space, particularly for structures such as Space-Based Solar Power (SBSP) systems in transit through the debris below 2000 km in altitude. Collision risk is much reduced in Geostationary Earth Orbit (GEO) since all the satellites are moving in the same direction at very close to the same speed.

If space exploration were to progress to the point of establishing a moon base, costs could be significantly reduced by building the infrastructure required out of the processed Lunar regolith, the loose material covering the Moon’s surface, and launching it from there. The low gravity of the moon would significantly lower the launch costs.

Could this be a reality?

While space-based solar power has remained a mainly theoretical concept for over 80 years, there is progress being made, a lot of it in recent years.

In May 2020, the US Naval Research Laboratory conducted its first test of solar power generation in a satellite.

In August 2021, the California Institute of Technology (Caltech) announced that it planned to launch a SBSP test array by 2023.

And finally, a team at Caltech successfully demonstrated beaming power to Earth in 2023, marking it as a milestone in the technology’s development.

So, the dream is not yet dead, and seems to be growing stronger every year. It is my hope that this trend continues and for there to finally be an end to our dependency on fossil fuels. I hope for this to be the beginning of a thriving orbital industry that can bring a future further out in the Solar System ever closer to reality.

ABOUT THE AUTHOR: Stawie is a tech-loving young optimist, intrigued by the mysteries of what lies ahead.

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