Montgomery County and advocates press for 15‑minute meter data to speed electrification; Exelon utilities cite $38M estimate and technical risk

Montgomery County and a coalition of energy advocates told the Public Service Commission that better, more granular interval data from smart meters could reduce barriers to home electrification by showing — in many cases — that a household does not need an expensive electrical panel or service upgrade before installing electric appliances.

County officials and the Maryland Energy Efficiency Advocates asked the commission to require utilities to make 15‑minute interval data accessible to homeowners, electricians and program administrators for use when assessing panel and service needs, especially in urgent "emergency replacement" situations. They argued that 15‑minute measured consumption is a better method to determine existing building load than the worksheet‑based approach often used today, and that access would prevent unnecessary upgrades that can add cost and weeks of delay to electrification projects.

Representatives of the Exelon utilities — which together cover a large share of Maryland customers — responded that the rollout of 15‑minute interval data for residential customers would require a complex, cross‑enterprise IT effort. Exelon said the joint estimate for the work was approximately $38 million at a 40% design contingency and outlined concerns about meter program changes, mass over‑the‑air updates, storage and meter‑operations modifications, and a non‑trivial failure rate that could trigger truck rolls and billing issues if not tested exhaustively. Exelon suggested lower‑cost alternatives and said it had asked for clarification of the requested use cases before moving forward.

Montgomery County asked the commission to require an RFI or third‑party assessment to validate the utilities’ cost estimate. County officials also proposed smaller pilots to compare the worksheet method with 15‑minute measured data in cases where 15‑minute data already exists or could be accessed without a full program change.

Exelon replied that residential meters are typically set up with 60‑minute interval data in their meter programs and that commercial customers already receive 15‑minute intervals because of different meter hardware and configurations. Exelon said it had provided separate cost estimates per utility in its filing and flagged potential risks of a mass over‑the‑air update. Exelon representatives also noted that, under the National Electric Code, measured demand can be used to size panels when a year of reliable demand data is available — an issue the parties disputed in interpretation: some stakeholders argued that measured demand can be derived from the existing interval data if it is available for a year; Exelon emphasized the practical operational risks in attempting to reconfigure meter programs across millions of residential endpoints.

Commissioners urged Montgomery County and the Exelon utilities to continue technical discussions with commission staff and technical advisors to identify narrow paths forward, including targeted pilots and a clearer statement of the testable use cases. Several commissioners said they would prefer an evidence‑based pilot before ordering an expensive, system‑wide change.