Plan to produce solar power in space

Virtus Solis plans to use the Starship rocket to launch a kilometer-wide solar cell to help produce and transmit electricity in space.

Virtus Solis , a Michigan startup founded by former SpaceX rocket engineer John Bucknell, introduced the idea of ​​transmitting solar power from space at the International Conference on Space Energy held in London in mid-month 4, Space reported on April 30. SpaceX's Starship rocket will change the race to produce solar electricity in space, making orbital power plants cheaper than many methods on Earth, according to Virtus Solis.

Simulation of Virtus Solis' on-orbit solar power generation system. (Photo: Virtus Solis)

The cost of launching satellites into space has plummeted in recent years thanks to the advent of reusable rockets that SpaceX pioneered. Currently, the company charges less than $3,000 per kilogram of goods, but that figure is still too high to produce solar power in space, which requires giant solar panels larger than the National Space Station. international (ISS).

SpaceX promises that after the Starship rocket becomes fully operational, the cost of launching satellites into space will decrease to 10 USD/kg. While the above estimate may be a bit optimistic, Bucknell believes that when launch costs to low Earth orbit fall below $200/kg, solar power in space will be cheaper than power from nuclear or power plants. use coal and natural gas above ground.

Currently, solar cells on Earth provide the cheapest power source, less than 30 USD/megawatt hour. But the Sun doesn't shine at night and energy experts are struggling to find ways to offset the decline in electricity with other renewable energy sources. Until now, nuclear, coal and gas power plants have been the backup plan to meet demand after dark or during bad weather. But thermal power plants will affect the emissions reduction goals that the world needs to achieve while nuclear power plants have much higher costs.

"The cost of nuclear power is at 150 - 200 USD/megawatt hour. Our system can reduce the cost to about 30 USD/megawatt/hour when applied on a large scale ," Bucknell said.

Virtus Solis wants to build giant solar panels one kilometer across that can be assembled in orbit by robots from modules 1.6 meters wide. Hundreds of such modules could be transported by a Starship rocket into Molniya orbit, an elliptical orbit with the closest point at an altitude of 800 km above Earth and the farthest at 35,000 km.

An orbiting satellite takes 12 hours to complete one revolution around the planet. But due to the nature of this orbit, the spacecraft can stay for more than 11 hours in the most remote areas. Therefore, a cluster of two or more satellites will provide regular background power to an area. The system of 16 solar cells will cover the entire world, transmitting energy in the form of microwaves to giant receiving antennas on the ground.

According to Bucknell, the company is currently looking to improve the efficiency of wireless power transmission, a major obstacle to solar power generation in space. Current systems have an efficiency of about 5%, but for practical use, efficiency needs to increase to 20%. In February, Virtus Solis announced plans to test a power transmission satellite in 2027 to test solar cell assembly in space and transmit more than a kilowatt of electricity to Earth. The company hopes to build a megawatt-level commercial solar power plant by 2030.