Space-based solar power returns as climate solution

Space-based solar power (SBSP) is back in fashion: put photovoltaic arrays in orbit, beam the energy to Earth, and sell “clean power everywhere” as the antidote to intermittency. Euronews’ Green vertical frames SBSP as a route to “beyond net zero,” but the hard part isn’t the slogan—it’s the link budget.

The basic architecture is well known. Large solar arrays in high orbit (often geostationary) generate DC power, convert it to RF (typically microwaves) or coherent light (lasers), transmit through the atmosphere, and reconvert at a ground receiver (a rectenna for microwaves, PV for lasers). Each conversion step takes a bite. In practice you stack losses: PV efficiency, power electronics, RF/laser generation, beamforming, pointing errors, atmospheric attenuation, receiver conversion, and grid interconnection. Even with optimistic component efficiencies, end-to-end delivered electricity is a fraction of incident sunlight.

Thermals and mass dominate. In orbit, waste heat has nowhere to go except radiators, which add area and mass. High-power RF amplifiers and laser systems are not magic; their inefficiency becomes radiator acreage. Then comes station-keeping and attitude control: a kilometer-scale phased array must hold pointing accuracy and phase coherence while being pushed around by solar pressure and gravitational perturbations.

The other constraint is brutally terrestrial: launch cost per kilogram. SBSP is a megastructure business. Even if reusable rockets keep falling in price, you still need to loft not just panels but trusses, radiators, transmitters, power conditioning, and assembly robots—or pay humans to do it. The mass-to-delivered-kWh ratio is the real metric, and it’s where most SBSP proposals quietly go to die.

Microwave vs laser is a trade between physics and politics. Microwaves are comparatively tolerant of clouds and can be spread into a wide, low-intensity beam, but require enormous apertures to keep the beam tight enough at long range. Lasers allow smaller apertures and tighter beams but are more sensitive to weather and raise immediate safety and airspace-control questions. Either way, “beam safety” becomes a regulatory industry: exclusion zones, aviation coordination, spectrum allocation, and liability regimes.

That is where the alarm bell rings. Once your powerline is literally a directed-energy link, the natural monopolists—states, defense ministries, and incumbent utilities—acquire a new argument for licensing, surveillance, and centralized control. A technology pitched as clean abundance risks being implemented as orbital infrastructure rent: a handful of operators owning the beam, the spectrum rights, the ground sites, and the interconnect.

Euronews describes SBSP as a way to deliver electricity to remote regions. That’s plausible only if the system can be modular, competitive, and permissionless enough to avoid turning “energy access” into “energy dependency.” If the business case requires sovereign guarantees, protected spectrum, and military-grade coordination, then SBSP won’t be a market breakthrough—it will be another state-backed megaproject, with physics doing the auditing after the press releases.