Electric Reliability - Commercial - New Hampshire Electric - Liberty



Electric Reliability
We work hard to provide our customers with unparalleled safe and reliable service. Despite our best efforts to prevent outages, there are factors beyond our control, such as adverse weather, which can occasionally knock out power.
To illustrate the company’s efforts in improving reliability for our customers, the chart below shows Liberty’s five-year rolling average for number of outages and average duration of each outage between 2004 and 2019.
In 2008 (four years before Liberty purchased the utility), the average electric customer was interrupted 2.15 times and was out of power for 243 minutes. Since then, the company’s reliability performance has improved considerably. As of year-end 2019, the average Liberty Utilities customer was interrupted less than one time during the year and the average duration was 98 minutes. This represents an improvement of approximately 40% for both duration and frequency of outages. The power was on 99.98 percent of the time.
How did we achieve these improvements? We made significant improvements to our infrastructure, effectively managed vegetation around our powerlines and responded quickly to outages when they do occur. Below is a list of measures we take to help increase reliability and decrease the number of power outages.
To ensure safety and electric service reliability, we schedule tree pruning in your area every four to five years adhering to the industry “best practices.” We only hire qualified contractors to do this work. We typically schedule pruning by electric circuit and time since last prune. We will also address significant tree hazards outside of our tree pruning schedule
For more information about vegetation management, please click the button below.
Increased Supply:
We increased our power supply in several of our service areas, installed new powerlines to reduce the number of customers impacted by outages and retired old equipment
- In 2013, a new substation on Michael Ave in Charlestown NH was constructed. We also added a new distribution feeder at the substation to support demand growth in Charlestown.
- In 2016, our substation in Lebanon, NH was expanded to install a second transmission line, a second transformer and two new distribution feeders.
- In 2017, our substation in Pelham was completely rebuilt and expanded to install a second transmission line, a second transformer and one new distribution feeder.
- In 2018, we extended one distribution feeder from the Pelham substation to the Salem area to support growth in the town of Salem.
- In 2019, our substation in Salem, NH was expanded to install a second transformer and two new distribution feeders. The installation of a second transmission line is in progress and is expected to be completed in 2020. We added the two new distribution feeders in Salem to enable the retirement of an aging substation in southern Salem. A new distribution feeder will be added in 2020 to improve the reliability for the customers in northeastern Salem
- In 2019, our substation in Charlestown was retired and load was transferred to the Michael Ave substation.
Bare Primary Wires:
We have begun to replace bare primary wires on cross-arm utility poles due to the susceptibility of trees/branches coming into contact with them and causing an outage. The bare wire is replaced with spacer cable (shown below), which is a covered wire resistant to tree related outages. Areas where these efforts have been completed are...
2017 2018 2019 2020 Lowell Rd, Salem RT 12, Walpole Tallant Rd, Pelham Bridge St, Salem Shore Dr, Salem RT 120, Meriden Wentworth Rd, Walpole Nashua Rd, Pelham Mammoth Rd, Pelham Bridge St, Pelham Sullivan St, Charlestown Burns Rd, Pelham Duttin Rd, Pelham Brookdale Rd, Salem Shaker Hill Rd, Enfield Mammoth Rd, Pelham RT 123, Walpole Watkins Hill Rd, Walpole (Spacer Cable)
Cable Replacements:
In 2016, we replaced approximately 600 feet of underground cable at a substation in Salem. In 2017, we replaced approximately 600 feet of underground cable at the Pelham substation.
In July of 2018, we began replacing approximately 1,700 feet of underground cables on Main St in Hanover.
In 2019, we replaced approximately 4,000 feet of underground cable on Central St in Salem.
In 2020, we will replace approximately 400 feet of underground cable at a substation in northeast Salem.
Distribution Automation:
Customers want to see a more modern power system that can respond quicker to problems and isolate them to smaller portion of the system. Distribution Automation will allow for the system to automatically respond to interruptions and restore unaffected portions of the system automatically.
In 2016, Liberty installed a distribution automation scheme between three distribution feeders in the town of Lebanon NH.
In 2019, Liberty installed a distribution automation scheme at the Rockingham Mall in Salem NH.
Between 2020 and 2021, we plan to install a distribution automation scheme between three feeders in northeast Salem NH and plan to install one new distribution automation scheme at the Tuscan Village Development in Salem NH.
Digsafe is a free service that helps prevent underground utilities from unintentionally being hit while digging. Throughout the year, we market this service to make sure our customers, third-party contractors and the general public are aware of this state law. We do this through social media, bill inserts, newsletters and in the welcome packets that all new customers receive.
We increase reliability by helping others to understand if someone hits an underground utility line, not only can it harm them, it can also cause a neighborhood wide power outage. In this instance, education is our greatest defense.
In order to continue providing our customers with a reliable source of power, we will be upgrading some existing distribution systems in our Salem service territory.
Battery Storage Is Happening!
In continuing efforts to decrease load on our infrastructure, lower energy costs for customers and provide a method of back-up power for participating customers, we have introduced a Battery Storage Pilot Program in NH. Our first installation has been completed!