Unitil Energy Systems

What This Utility Data Tells You

Unitil Energy Systems is a investor-owned utility operating in New Hampshire under EIA identifier 24590. It reports service to approximately 64,256 customer accounts and generated about $0.18 billion in annual electric revenue, with a service footprint spanning 39 ZIP codes. As an investor-owned utility, it operates under state public utility commission oversight that reviews rate cases and reliability performance.

In 2023, the average Unitil Energy Systems customer experienced 256.6 minutes of power interruptions — a metric called SAIDI (System Average Interruption Duration Index). That sits within the 120–180 minute national benchmark range, indicating performance typical of U.S. distribution utilities. SAIFI — the average number of outage events per customer — was 1.55 for the same period, so customers statistically faced roughly 2 distinct interruptions that year. Excluding major event days (hurricanes, ice storms), SAIDI drops to 90.9 minutes — the gap between that figure and the headline 256.6 reveals how much weather, not day-to-day infrastructure, drove outages.

The EIA dataset includes 4 years of continuous reporting (2020–2023) for Unitil Energy Systems, which lets you see whether reliability is trending up or down rather than judging from a single snapshot. SAIDI has increased from 176.6 to 256.6 minutes, which may reflect either worsening weather exposure or delayed grid modernization. All figures on this page come directly from EIA Form 861, the federal annual electric power industry survey, with service territory ZIPs sourced from OpenEI — you can cross-reference them with your own utility bill or use them when comparing providers before relocating.