Why GEO rather than LEO or MEO for this application?

GEO provides near-continuous solar illumination—approximately 99% of the time versus roughly 40% in LEO—and a fixed position relative to the ground rectenna, which dramatically simplifies beam pointing and eliminates the need for a large receiving array that must track a moving target. The tradeoff is the enormous mass that must reach a very high orbit and the higher radiation environment. LEO constellations have been studied but produce intermittent power delivery unsuitable for baseload generation.

Is microwave beaming safe for people and aircraft near the rectenna?

Studies by JAXA, ESA, and the US Naval Research Laboratory consistently show that a properly designed rectenna operates within IEEE C95.1-2019 safety thresholds at its perimeter—power density at the fence line is typically modelled below 1 mW/cm², comparable to a mobile phone held at distance. Aircraft overflight is a more complex issue; beam-safety interlocks that detect and cut transmission within milliseconds are a standard design requirement. No large-scale operational system has yet produced real-world safety data, however.

Why should a nation own this rather than buy power from a commercial SBSP operator?

A foreign-owned SBSP plant delivering gigawatts to your grid is a single-point vulnerability: the operator can reprice, redirect, or cut the beam. Energy is the foundational input to every sector of a sovereign economy. Owning the orbital asset means controlling the spectrum license, the orbital slot, the beam-pointing authority, and the rectenna infrastructure—none of which should be delegated to an external commercial or foreign-state entity.

What is a rectenna and how large does it need to be?

A rectenna (rectifying antenna) is a ground array that converts the received microwave beam into DC electricity. For a 2 GW plant using a 2.45 GHz beam, the rectenna would typically be 5–10 km in diameter depending on orbital altitude and beam width. Semi-rural or offshore placement is generally preferred to avoid urban exclusion zones, and the land beneath the array can often still be used for low-clearance agriculture.

How does SBSP compare economically to terrestrial renewables?

At today's launch costs, SBSP electricity would cost hundreds of dollars per kWh—completely non-competitive. The ESA SOLARIS team estimates that at $400/kg launch costs and with mature in-space assembly, SBSP could reach $0.10–0.15/kWh, approaching competitive territory for baseload power in land-constrained or high-latitude nations. The IEA currently prices utility-scale solar at $0.03–0.06/kWh in prime locations, so SBSP remains a premium option justified by continuous availability and geographic independence.

Which nations are furthest along in SBSP development?

Japan's JAXA has the longest continuous research programme, running since 2009 with ground demonstrations of microwave power transmission. The European Space Agency launched its SOLARIS initiative in 2022 with a feasibility study funded at roughly €20M. The UK committed to a £3M study in 2022 resulting in a positive feasibility finding. China's CAST has publicly stated a target of a 1 MW test satellite by the late 2020s and a 1 GW system by 2050. The United States' effort is largely at the Naval Research Laboratory and AFRL experimental level.

What orbital slots would a national SBSP system need, and how are those secured?

SBSP plants would occupy GEO slots coordinated through the ITU under the Radio Regulations. Filing must be made through the nation's national telecommunications authority, and coordination with adjacent satellite operators is mandatory under ITU Radio Regulations Article 9. GEO slots are a finite and increasingly contested resource; nations that file early gain procedural priority. A sovereign programme filing its own ITU coordination positions itself far better than one depending on a commercial operator's slot.

What happens to SBSP hardware at end of life—does it become debris?

ISO 24113:2023 and the IADC guidelines require GEO operators to manoeuvre end-of-life satellites to a graveyard orbit roughly 300 km above GEO within the satellite's propellant budget. For a structure of SBSP scale, active deorbiting or controlled graveyard disposal is a major design and propulsion challenge that has no precedent. COPUOS long-term sustainability guidelines (A/AC.105/C.2/L.315) flag large orbital structures as a priority area requiring new international norms, which do not yet exist.

16.5.1Speculative

In-Space Solar Power Plants

Workers installing electrical infrastructure in a rural African village — Workers installing rooftop solar panels represent the Earth-side infrastructure that receives and distributes power beamed from orbital solar plants.

Orbital Solar Plant to Earth Power Grid

1
Solar Collector
GEO satellite harvests uninterrupted sunlight 24/7
2
Microwave Beam
2.45 GHz beam transmitted to ground rectenna
3
Rectenna Array
Converts microwaves to DC electricity on ground
4
National Grid
Conditioned AC power fed to homes and industry

A geostationary solar collector beams power continuously to a ground rectenna, feeding clean baseload electricity into the national grid.

Page in the build queue

This application has its place in the atlas. The full page — short and long descriptions, what-matters bullets, sovereignty rationale, and the eight-field architecture block — is being written next.

Maturity reading: Coherent concept; no operational deployment yet. Phase 1 built §4.1 (Maritime Intelligence) end-to-end as the depth-and-format reference. Section 4 is the next section to graduate from scaffold to full content; the rest follow on the roadmap.

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16.5.2 · Next

Orbital Industrial Parks

Bring this into your sovereign programme.

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