Virtus Solis plans to use the Starship rocket to launch a one-kilometer-wide solar panel, aimed at generating and transmitting power in space.
Virtus Solis, a startup based in Michigan founded by former SpaceX rocket engineer John Bucknell, introduced the concept of transmitting solar power from space at the International Space Energy Conference held in London in mid-April, as reported by Space on April 30. SpaceX’s Starship rocket is set to revolutionize solar power generation in space, allowing orbital power plants to operate at lower costs compared to many methods used on Earth, according to Virtus Solis.
Simulation of Virtus Solis’ orbital solar power generation system. (Image: Virtus Solis)
The cost of launching satellites into space has dramatically decreased in recent years due to the advent of reusable rockets pioneered by SpaceX. Currently, the company charges under $3,000 per kilogram of payload, but that figure is still too high for solar power generation in space, which requires massive solar panels larger than the International Space Station (ISS).
SpaceX promises that once the Starship rocket is fully operational, the cost of launching satellites into space will drop to $10 per kilogram. Although this estimate may be somewhat optimistic, Bucknell believes that when the cost of launching to low Earth orbit falls below $200 per kilogram, solar power in space will become cheaper than power from nuclear or fossil fuel plants on the ground.
Currently, solar panels on Earth provide the cheapest electricity, costing under $30 per megawatt-hour. However, the sun does not shine at night, and energy experts are struggling to find ways to compensate for the drop in electricity generation with other renewable sources. So far, nuclear, coal, and natural gas plants remain backup options to meet demand after dark or during inclement weather. However, thermal power plants impact the emissions reduction goals that the world needs to achieve, while nuclear plants are significantly more expensive.
“The cost of nuclear power is around $150 – $200 per megawatt-hour. Our system could reduce costs to about $30 per megawatt-hour when scaled up,” Bucknell noted.
Virtus Solis aims to manufacture gigantic solar panels that are one kilometer wide, which can be assembled in orbit using robotic modules that are 1.6 meters wide. Hundreds of such modules can be transported by a Starship rocket to a Molniya orbit, an elliptical orbit with a closest point at an altitude of 800 km above Earth and a farthest point at 35,000 km.
A satellite in this orbit takes 12 hours to complete one orbit around the planet. However, due to the nature of this orbit, the spacecraft can remain for more than 11 hours in the most distant region. Therefore, a cluster of two or more satellites will provide a constant power supply for a particular area. A system consisting of 16 solar panels would cover the entire world, transmitting energy in the form of microwaves to huge receiving antennas on the ground.
According to Bucknell, the company is currently working on improving wireless power transmission efficiency, a significant barrier to solar power generation in space. Current systems operate at an efficiency of about 5%, but for practical use, this needs to be increased to 20%. In February, Virtus Solis announced plans to test a power-transmitting satellite in 2027 to verify the assembly of solar panels in space and transmit over one kilowatt of electricity back to Earth. The company hopes to establish a commercial megawatt solar power plant by 2030.
