From concept to patent race: the space solar power inflection point

Space solar power — collecting solar energy in orbit and transmitting it wirelessly to Earth — sits at a genuine inflection point in 2026, as terrestrial energy pressures and renewed space-economy investment converge. The technology encompasses three linked domains: orbital collection and conversion using photovoltaic or concentrating arrays; wireless power transmission (WPT) via microwave or laser beams; and ground reception through rectenna arrays that reconvert transmitted energy into DC power for terrestrial grids. According to WIPO, energy-related patent filings have grown substantially over the past decade, and SSP represents one of the most technically ambitious sub-sectors within that trend.

The timeline of innovation in this dataset stretches from 1981 — when Ernst Weber’s German filing described a ring of artificial planetary-orbit satellites reflecting solar radiation to ground stations — to 2025 commercial filings targeting near-term pilot deployment. That 44-year arc contains a clear acceleration: the 2022–2026 window holds the highest concentration of SSP-specific filings in the entire dataset, with five distinct directional signals emerging in rapid succession.

A secondary but increasingly prominent sub-domain involves extraterrestrial surface power infrastructure — specifically lunar base energy systems — while a third support layer covers AI and multi-agent coordination for managing distributed orbital assets and optimising beam steering. Together, these four clusters form a coherent picture of where SSP innovation is concentrated and where white space remains.

Four technology clusters shaping the space solar power patent landscape

The 14 core SSP patents in this dataset organise naturally into four clusters, each representing a distinct engineering approach to the problem of capturing and delivering solar energy from space. Understanding the boundaries of each cluster is essential for freedom-to-operate analysis and R&D roadmap planning, as noted in guidance from both EPO and USPTO on technology landscaping methodology.

Cluster 1: Microwave-based wireless power transmission (phased array)

This is the most thoroughly developed approach in the dataset. Power satellites convert photovoltaic DC output into high-frequency microwave beams using phased-array antennas; ground rectenna arrays receive and rectify the beam to DC. Phase coherence across distributed transmitter elements is the central engineering challenge. Mitsubishi Electric’s 2004 DE filing introduced a dedicated control satellite that measures each power satellite’s position and computes individual phase-adjustment values. California Institute of Technology’s EP patent (2023) advances this by coordinating distributed reference signals across modular satellite tiles to determine phase shift and amplitude modulation. Century Green Energy (TW, 2025) deploys this approach in a LEO constellation format, transmitting to earth-surface rectenna arrays and DC storage modules.

Cluster 2: Optical / laser beam power transmission

A newer architectural strand replaces microwave with laser or concentrated optical beams. Overview Energy Inc.’s dual 2025 filings in KR and JP represent the most commercially advanced optical SSP patents in the dataset. The KR filing describes an artificial orbital light source projecting one or more optical beams onto a photovoltaic array 200 m to 20 km in extent on Earth or another celestial body. The JP companion filing elaborates that optical SSP systems offer potentially higher allowable safety intensity thresholds than microwave counterparts and may operate with a smaller overall orbital aperture. Astrium SAS’s 2013 ES filing provides an earlier precursor: a retransmission satellite that captures sunlight via a fixed first optical assembly and re-scatters it with a smaller, steerable second assembly, increasing re-scattered flux density directed to Earth.

Cluster 3: Multi-agent AI cooperative control for SSP energy routing

Chinese university filings dominate this cluster, which addresses the coordination of fleets of power satellites across multiple orbital regimes. Shenyang Aerospace University’s 2021 CN filing established a framework in which stations on dawn-dusk sun-synchronous orbit collect solar energy and relay it to GEO stations, which then transmit to ground, with custom distance functions and multi-agent attitude coordination governing beam routing. Xidian University’s 2020 CN filing introduced a deep-learning-based global cooperative control system that trains on operational data to optimise output magnitude and direction across distributed transmitting agents. Shenyang Aerospace University’s 2023 follow-on extends the framework with co-located backup satellites that take over when primary stations fail, improving system-level fault tolerance.

Cluster 4: Extraterrestrial surface power infrastructure

This cluster focuses on sustaining energy supply for lunar and deep-space bases rather than transmitting power to Earth. Astrobotic Technology’s Lunar Power Grid Assembly (JP, 2024) interconnects vertical solar arrays at two lunar sites via cable, with one charging a storage device while the other maintains thermal stability. China Three Gorges University’s 2025 CN filing places PV arrays at the Shackleton Crater rim — which receives more than 90% annual illumination — combined with thermal-storage Stirling generator systems at day-night transition zones, with a multi-objective optimisation minimising total transport mass. Harbin Institute of Technology’s 2022 CN filing wraps thermoelectric materials around high-capacity thermal storage units installed in lunar lava tube shelters, generating continuous electricity from temperature differentials.

Geographic and assignee concentration: who holds what in space solar power IP

Within the 14 directly SSP-relevant records in this dataset, China is the most active jurisdiction, accounting for approximately 6 of 14 core SSP filings. These are distributed across major universities — Xidian University, Shenyang Aerospace University, Northwest University, Harbin Institute of Technology, and China Three Gorges University — and one government research institute, the China Academy of Space Technology. This pattern reflects coordinated national investment in SSP as a strategic energy technology, a posture consistent with broader Chinese space policy as tracked by organisations including OECD in its space economy reports.

Japan contributes 5 records across Mitsubishi Electric, Mitsubishi Heavy Industries, Hitachi, and California Institute of Technology’s JP-family filings. The presence of Caltech’s JP filing alongside the two Mitsubishi entities illustrates both domestic industrial engagement and international protection strategies by US academic institutions. Overview Energy Inc., a US commercial entrant, filed in both KR and JP in 2025, signalling active commercialisation intent rather than defensive IP positioning.

“Innovation in this dataset is concentrated among a small number of assignees — the two Mitsubishi entities, Caltech, Shenyang Aerospace University, and Xidian University each account for multiple records. No single commercial entity dominates broadly, suggesting the field remains pre-competitive in IP terms.”

Taiwan (Century Green Energy, TW, 2025) and South Korea (Overview Energy Inc. KR filing) contribute recent commercially oriented filings. Europe (Astrium SAS/ES, 2013; Caltech/EP, 2023) and Germany (Mitsubishi Electric/DE, 2004; Ernst Weber/DE, 1981) round out the geographic picture. The overall assignee landscape is notable for its absence of dominant commercial players: no single entity holds a broad portfolio across multiple SSP sub-domains, which is consistent with a field that remains pre-competitive in IP terms.

Five emerging directions from the 2022–2026 space solar power filing window

The 2022–2026 period contains the highest concentration of SSP-specific filings in this dataset, and five directional signals are clear from the claims and assignee strategies observed.

1. Optical/laser SSP commercialisation (2025). Overview Energy Inc.’s dual KR and JP filings in 2025 represent the most commercially advanced optical SSP patents in the dataset. The claims emphasise practical ground aperture dimensions — 200 m to 20 km — suggesting near-term pilot deployment thinking rather than conceptual exploration. Optical SSP may face a lower entry barrier than microwave SSP because it avoids the large ground aperture requirements of rectenna arrays and the international frequency coordination issues associated with microwave transmission.

2. Real-time beam efficiency optimisation at ground receivers (2024). Hitachi’s 2024 JP filing introduces ground-side feedback for estimating beam direction and commanding the orbital facility to adjust — closing the control loop between rectenna and satellite. This represents a meaningful step toward operational SSP systems that can self-correct in real time.

3. Fault-tolerant multi-agent SSP control (2023). Shenyang Aerospace University’s 2023 CN filing extends its 2021 framework with co-located backup satellite systems with autonomous fault recovery. This upgrade addresses one of the most significant operational risks for large SSP constellations: the failure of individual transmitting nodes in a coordinated fleet.

4. Lunar power system optimisation with ISRU integration (2025). China Three Gorges University’s multi-objective optimisation model integrates in-situ resource utilisation (ISRU)-derived thermal storage into a hybrid PV/Stirling system specifically optimised for the Shackleton Crater region, which receives more than 90% annual illumination. The optimisation objective explicitly minimises total transport mass — a critical constraint for any lunar infrastructure programme.

5. Integrated electro-optical-mechanical SSPS architecture (2022). Xidian University’s OMEGA-2.0 filing resolves prior design conflicts — specifically, the microwave transparency of film mirrors and high-voltage brush power transfer — via spherical concentrator geometry integrated with omnidirectional transmission antennas. This represents a systems-level architectural advance rather than an incremental improvement to a single subsystem.

“Multi-agent AI control for SSP fleet management is developing rapidly in the CN jurisdiction but has limited counterpart filings in US, EP, or JP — creating a potential dependency risk for Western SSP developers who do not build equivalent independent IP.”

Strategic implications for IP teams and R&D leaders in space solar power

The patent landscape described above carries several concrete implications for IP strategy and R&D prioritisation. These are derived directly from the filing patterns, assignee strategies, and claim structures observed in this dataset.

Assess freedom-to-operate against Caltech’s phased-array portfolio. Caltech’s EP (2023) and JP (2021) patents represent a foundational IP position in the high-value beam-steering and modular tile architecture space. Any commercial entrant developing a microwave SSP system should conduct a freedom-to-operate analysis against this portfolio before committing to hardware development roadmaps. The multi-jurisdiction filing strategy — EP and JP — indicates deliberate international IP protection rather than domestic-only coverage.

Monitor CN publications from Chinese university clusters. China’s university-led filing cluster — spanning Xidian University, Shenyang Aerospace University, Northwest University, Harbin Institute of Technology, and China Three Gorges University — reflects a coordinated national R&D posture in which multiple competing architectures are being developed in parallel. These filings are increasingly cross-jurisdictional, and IP strategists at Western aerospace primes should track CN publications from these institutions systematically. Resources such as PatSnap’s IP intelligence platform can support this monitoring at scale.

Consider the lunar power infrastructure white space. The lunar power infrastructure sub-domain is underserved by commercial IP relative to its strategic importance. Astrobotic Technology is the only identifiable commercial assignee in the lunar power filings in this dataset; the remainder are universities and government institutes. This gap may represent a near-term white space for IP position-building by companies engaged in lunar logistics and construction — particularly as national lunar programmes accelerate under frameworks such as the NASA Artemis programme.

Evaluate independent AI control IP development. Multi-agent AI control for SSP fleet management is developing rapidly in the CN jurisdiction but has limited counterpart filings in US, EP, or JP. R&D teams at Western SSP developers should assess whether equivalent control architectures are needed and whether independent IP development is warranted to avoid dependency on CN-held methods.

Optical SSP as a lower-barrier entry path. Overview Energy Inc.’s 2025 filings suggest that optical SSP may face a lower entry barrier than microwave SSP by avoiding large rectenna ground aperture requirements and international microwave frequency coordination issues. The 200 m to 20 km claimed ground aperture range suggests compatibility with existing large-scale terrestrial PV installations as receivers. IP teams evaluating SSP entry strategies should weigh this regulatory and infrastructure advantage against the current maturity gap between optical and microwave approaches. For broader context on wireless power transmission standards and spectrum allocation, ITU publications provide authoritative guidance on the frequency coordination considerations relevant to microwave SSP systems.