Airbus Defence and Space is investigating the use of space platforms—essentially large satellites—to collect solar energy and redirect it using laser beams to specially equipped receivers on Earth. The company's proposed space-based solar power (SBSP) system would help meet the world’s growing energy requirements without increasing the heat and gases emitted into the atmosphere.

The company says the SBSP platforms would be placed in geostationary orbit to ensure a permanent visibility of ground receivers. From such a position, energy could be directed to locations on the visible portion of the Earth’s surface.

Satellites would collect the sun's energy and redirect it using laser beams to receivers on Earth. Image credit: NASA.Airbus says the energy would be redirected using laser beams that operate at "eye-safe" wavelengths (around 1.5 µ) and at a power density of no more than 1,000 W/m² (equivalent to solar flux)—and thus safe for humans and animals. A single satellite would be capable of providing around 10 kW to the ground end user, the company says.

"This basic building block and improvements to it could then be used to construct multi-satellite systems providing power to users with no access to existing electrical power grids," the company says.

According to the U.S. Department of Energy, such concepts have potential. Since clouds, atmosphere and nighttime are absent in space, satellite-based solar panels would be able to capture and transmit substantially more energy than terrestrial solar panels.

Laser solar satellites, the agency notes, incur relatively low startup costs—in the $500 million to $1 billion range. The small diameter of the laser beam makes the ground-based technology relatively simple and inexpensive to implement.

On the down side, DOE says, laser-transmitting satellites would have trouble beaming power through heavy clouds and rain. Potential safety concerns include their ability to be weaponized.