Unitil Energy Systems

What This Utility Data Tells You

Unitil Energy Systems is an 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. Because it is investor-owned, the state public utility commission oversees its rate cases and reliability performance rather than a local board.

In 2023, the average Unitil Energy Systems customer experienced 256.6 minutes of power interruptions, the industry-standard SAIDI metric (System Average Interruption Duration Index). Excluding major weather events from that total, that keeps this utility below the typical 120–180 minute national benchmark, consistent with a well-hardened distribution system and fast restoration crews. The SAIFI figure, which tracks average outage events per customer, came in at 1.55 for the same period, meaning customers statistically saw about 2 distinct interruptions that year. Once major event days (hurricanes, ice storms) are excluded, SAIDI comes down to 90.9 minutes, and the spread against the headline 256.6 indicates how much weather, versus routine infrastructure, drove the outage total.

Unitil Energy Systems has 4 years of continuous EIA reporting on file (2020–2023), enough to read a real trend rather than a single-year snapshot. SAIDI has increased from 176.6 to 256.6 minutes, which may reflect either worsening weather exposure or delayed grid modernization.