The futuristic idea of sending solar energy to Earth is now a reality. Since June last year, a space experiment has transmitted energy to Earth through the solar panels of an orbiting satellite.
With its MAPLE experiment (Microwave Array for Power-transfer Low-orbit Experiment), the Space Solar Power Demonstrator (SSPD) has demonstrated that it is possible to transmit energy in space and from space to Earth. It is the first time that solar energy has been transmitted from orbit and could be the first step towards a solar power plant in space.
First launched in January 2023, the device was capable of transmitting about 100 milliwatts worth of energy through space just two months later, and could easily be refocused to send the beam in any direction. In the test of sending energy to Earth, the power that reached our planet was approximately 1 milliwatt and was carried out three times over eight months.
Vast potential for the future
The idea is to create a constellation of modular spacecraft about one kilometer in scale that can transmit enough energy to power 10,000 homes. The individual satellites, measuring 1 cubic meter, will be deployed in a flat square 50 meters on each side with solar cells on one side and microwave transmitters on the other.
Since MAPLE can emit energy in any direction, the idea is that it can directly send energy and power to a remote location or during an emergency, since it does not require transmission infrastructure.
“Just as the Internet democratized access to information, we hope that wireless energy transfer will democratize access to energy,” SSPP senior researcher and co-director Ali Hajimiri said last year.
“No on-ground power transmission infrastructure will be required to receive this power. “This means we will be able to send energy to remote regions and areas devastated by war or natural disasters.”
The SSPD has other components that are being tested together with MAPLE: DOLCE (Deployable on-Orbit ultraLight Composite Experiment), which is testing the deployment structure of the spacecraft architecture, and ALBA, which is testing the best type of photovoltaic cells to use. Their results have not yet been released, but they are crucial components for the SSPD.