The ranking behind this landscape covers 100 companies across 416 records, with the leading assignee holding 32 records, fifth place holding 13 and tenth place holding 9. The gap after the top few filers is steep, and the top 10 combined account for 36.5% of all records in scope, so no single company controls the field outright. Most of the leading names are power-electronics or grid-storage specialists rather than CSP thermal-plant builders, which tracks with the technology composition data showing power conversion and grid systems as the densest claim areas.

Filings peaked at 25 in 2018 and have since eased, moving from 23 in 2021 down to 11 in 2024, a -52% change over that span. However, patent publication typically lags actual filing by around 18 months, so the 2025 and 2026 counts in any dataset are still incomplete and should not be read as confirming a further drop. The honest read is that activity cooled through the early 2020s relative to the 2018 peak, with the most recent trend still unresolved.

Power conversion (IPC class H02M) and power supply/grid systems (H02J) are the two densest areas, each touching roughly a quarter of the 416 records in scope. Battery and cell chemistry (H01M) trails well behind at 8.2%, with steam/thermal power plants (F01K), heating circuits (H05B), EV propulsion (B60L), mechanical storage (F03G) and semiconductors (H01L) each in the 5-8% range. Because a single record can carry multiple IPC classes, these percentages sum to more than 100% of the record total and should be read as overlapping claim density, not mutually exclusive shares.

US11736014B1, assigned to Vicor Corporation and published in 2023, claims an isolated three-phase AC-to-DC converter that uses a cascade of two conversion stages per phase, with galvanic isolation and power factor correction concentrated in specific stages. It is a representative filing in this landscape rather than a uniquely dominant one, and its scope is tied to that particular multi-stage isolation architecture. Work using a different isolation topology, a single-stage design, or storage/filtering distributed elsewhere in the circuit would sit outside its literal claim scope, though a full freedom-to-operate check requires reading the claims in detail rather than the abstract alone.

The IPC composition shows claim density concentrated in power conversion and grid systems, while branches like mechanical or gravitational bulk storage, cryo-energy storage hubs, and CSP thermal receiver integration carry comparatively few of the 416 records. The long tail in the 100-company ranking — many filers with only one or two records — also suggests the field has not been fully staked out beyond the leading handful. Any first claim aimed at these areas should be checked against the specific leading assignees' existing filings before drafting, since power-electronics incumbents may already hold adjacent ground.