Follow the filing velocity and one fact jumps out of the 2021 smart-grid metering data: two assignees do most of the named filing, and almost everyone else files once. The cluster is concentrated at the top and very long in the tail.
Causam Enterprises is the clearest pattern. Across the smart-grid/metering search facet, Causam carries the largest named-assignee count — filings like US20210376656A1 (grid element management), US20210090185A1 (blockchain energy settlements), and US20210072780A1 (secure grid messaging). That is not three patents; it is a coordinated campaign on the coordination layer.
Johnson Controls anchors the building side, with US10901446B2 and its companion publication US20210149429A1 ("Smart Building Manager"). These fence off energy management at the building/microgrid scale — the demand side of the smart grid — rather than the network coordination Causam pursues.
Below those two, the field fragments fast. Smart-meter hardware filings (e.g. US20210003978A1) tend to be unassigned single shots. The metering device was not where the IP concentration was happening; the orchestration software was.
What the counts signal strategically: in 2021, the value in smart grid was being claimed at the software/coordination layer by a handful of portfolio builders, not at the meter. The standard caveat holds — publications and grants are different populations, one CPC cluster is not the whole field, and an unassigned publication can still assign on grant. But the shape is unambiguous: concentrated software IP, diffuse hardware IP.