Maine regulators will investigate how Central Maine Power Co. and Emera Maine prepared for and responded to the largest power outage in the state's history, an event that also tested the limits of smart meters. The Maine Public Utilities Commission voted unanimously Dec. 12 to launch an investigation into the utilities' failure to quickly bounce back from the Oct. 29-30 landfall of remnants of Tropical Storm Philippe, which left 404,000 Central Maine Power, or CMP, customers and 90,000 Emera Maine customers without electricity.
"Some customers were without service for more than a week," said PUC Chair Mark Vannoy. CMP restored more than 97% affected customers by the evening of Nov. 4, with remaining outages restored by Nov. 8. The restoration efforts were complicated by flooding and the blocking of roads by downed trees, as relayed in Gov. Paul LePage's Nov. 30 request for federal assistance to repair $4.7 million in public infrastructure damage across 13 counties.
A car leaves a trail of light as it passes under power lines downed by trees in Freeport, Maine, on Oct. 31. Source: The Associated Press |
"The falling trees pulled down wires, snapped more than 1,400 poles and left many roads impassable, causing widespread power outages greater than those of the 1998 Ice Storm," said Gov. LePage in his request to U.S. President Donald Trump. "Several communities spent days clearing debris that created life-safety issues from public rights-of-way. The cost for that clean-up work will be considerable and will cut deeply into public works budgets."
In their notice of investigation, the PUC directed Central Maine Power, a subsidiary of Iberdrola SA's majority-owned Avangrid Inc., and Emera Inc. subsidiary Emera Maine to file within 30 days reports detailing their preparedness, restoration responses, lessons learned from the blackout and expected changes in their planning for the future. In addition to finding out how reliability and restoration efforts were coordinated, the commissioners will be reviewing current outage policies.
"The October wind storm caused more outages than any other in our history, and our recovery was swift, efficient, and most importantly, safe," said Avangrid spokesperson Gail Rice in a statement. Rice added that it is normal for the commission to investigate storm responses and said Avangrid looks forward to working with the commission in its evaluation of the utility's storm response.
Smart meter network tested
The windstorm also temporarily took out half of Central Maine Power's $200 million network of smart meters, which had been installed at more than 60,000 homes and businesses and backed-up with eight-hour batteries. Rice said the smart meters remotely measured the extent of the outage while simultaneously sending automated texts and emails to customers about expected restoration times.
"Since outages extended longer than [eight hours] in many areas, some devices began to lose power and, consequently, their ability to communicate with us," said Rice. "Even when power to devices in the field was out, many parts of the system still worked. For example, we could still 'ping' meters in any given area and confirm whether or not power was restored."
According to Avangrid, the meters' communication performance bottomed out at 48% on Oct. 31 before rebounding as restoration progressed, with 90% back in communication with the utility on Nov. 4 and 100% on Nov. 8. "This was the first time the [advanced metering infrastructure] system had been subjected to a prolonged outage, so we did learn something new about this system limitation," said Rice.
Emera did not immediately respond to request for comment. (Docket No. 2017-00324)

