Could space-based solar power be the answer to our energy needs?

In his 1941 short story, Reason, American author Isaac Asimov was the first to envision a world powered by solar power harvested in space. Then it seemed like just another piece of science fiction, however, this dream ultimately transformed into reality.

Four years ago, news hit that China was planning to build the world’s first solar power station to be positioned in Earth’s orbit. The theory of this is that the sun always shines in space. Therefore, the station could be seen as a continuous supply of clean energy and a means for us to move away from fossil fuels. 

The aim was to establish this by 2030, but China brought it forward to 2028. In the meantime, however, there has been some progress from scientists in other parts of the world determined to find a way to utilise space for enhanced solar power to Earth. The idea of space solar power has been investigated as every few decades; it has once again become a hot topic of conversation. 

Usually, the cost of launching these large satellites is prohibitive. However, it seems things are positively different this time around. In June of this year (2023), scientists successfully transmitted energy from space to Earth for the very first time. They were able to collect solar power to receivers in space and, from there, direct the energy to Earth. 

The Microwave Array for Power-transfer Low-orbit Experiment (MAPLE) proved the viability of tapping into an almost limitless power supply in the form of energy from the sun from space. Unlike our world, solar energy in space isn’t affected by factors such as night and day, weather, or obscuration by clouds. In other words, solar energy is always available, and research from Space reports that space-based harvesters could potentially extract eight times the amount of power than that of solar panels at any location on Earth. 

The wireless power transfer came through the MAPLE, an array of lightweight and flexible microwave power transmitters that are one of three instruments carried by the Space Solar Power Demonstrator (SSPD-1). As part of the California Institute of Technology’s (Caltech) Space Solar Power Project (SSPP), SSPD-1 was launched in January 2023.

The main aim behind the project was to harvest solar power in space so it could then be transmitted to the surface of Earth. MAPLE tested the transmission of energy wirelessly via space. They did this by sending energy from a transmitter to two separate receiver arrays roughly a foot away. From here, it was transformed into electricity and utilised to light up a pair of LEDs. 

On the roof of one of the buildings on Caltech’s campus in Pasadena, the instrument beamed energy from a tiny window that was installed. Through the experiment, the scientists were also able to illustrate its capability to function in the harsh environment of space whilst being exposed to solar radiation and significant temperature changes. 

This is just the first step, as MAPLE will soon be testing large-scale SSPP units with these conditions. The wireless transmission of energy through space is based on ‘interference’, a quantum phenomenon. Wave-like nature of light causes interference to arise, and the waves must align and create a bigger peak to ensure its success.

This isn’t the only time Asimov has predicted the future state of our world. He also wrote about how human’s relationship with nature would be reflected in 2014. In 1964, Asimov wrote: “Men will continue to withdraw from nature to create an environment that will suit them better.” 

Many believe solar power could dominate the energy landscape of the future, leading to better energy security whilst enabling us to curb global carbon emissions. Could space-based solar power be the answer to overcoming the current barriers of harnessing solar energy on Earth? Do you think space-based solar power is just having its moment in the sun? Let us know what you think in the comments below.

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