Terms & Definitions
Advanced Metering Infrastructure (AMI)
An integrated system of smart meters, communications networks and data management systems that enables two-way communication between utilities and customers.
Automated Meter Reading (AMR)
Technology that automatically collects data from your gas or electric meter and transfers it to a central database for analyzing, billing and troubleshooting purposes. AMR provides accurate readings on the final day of your billing cycle as well as data at various intervals throughout the billing period. For gas meters, Unitil utilizes the AMR system to capture customer meter readings wirelessly, without visiting your location.
Blue sky outage
A power outage that occurs during a normal, routine operating day for a utility, outside of any emergency or weather event.
Corrugated Stainless Steel Tubing (CSST)
An opportunity for consumers to play a significant role in the operation of the electric grid by reducing or shifting their electricity usage during peak periods in response to time-based rates or other forms of financial incentives. Demand response programs are being used by some electric service providers as resource options for balancing supply and demand. These programs can lower the cost of electricity in wholesale markets and, in turn, lead to lower retail rates.
Distributed Energy Resources (DERs)
Energy generation and storage performed by a variety of smaller systems that are located near where they are needed, as opposed to centralized sources (e.g. coal, natural gas, nuclear, large hydropower), which transmit large amounts of power over long distances.
Distribution utility (gas & electric)
A company that distributes natural gas and/or electricity to customers in a specific geographic area.
The process of replacing technologies that use fossil fuels as a source of energy with technologies that use electricity, which has the potential to reduce carbon dioxide emissions.
Emergency Operations Center (EOC)
A central command and control facility where system-wide plans are handled at a strategic level during an emergency. A utility’s EOC is responsible for carrying out emergency preparedness and management activities, as well as ensuring continued operations of the company.
Human behavior or effort made to reduce the consumption of energy. Using less energy and reducing waste can be accomplished in many daily activities, including: air drying clothes/dishes, cold water washing laundry, closing windows while air conditioning/heating systems are running, powering down electronics when not in use, setting back heating a few degrees, turning off lights, unplugging phone chargers, wearing a sweater, etc.
Using less energy to get the same job done with advanced energy saving technology — such as high efficiency light bulbs, ENERGY STAR® certified appliances, electronics, heating/cooling/water heating equipment, smart thermostats, weatherization, etc. — and in the process, cutting energy bills and reducing waste and pollution.
Estimated Time of Restoration (ETR)
An approximate window of time when utility service is expected to be restored following an interruption. Estimates are based on field conditions and other factors, and may change as the situation unfolds.
An abnormal electric current.
A large, underground pipeline that conveys gas to smaller pipes for local distribution to customers’ homes and buildings.
The integration of new technology and two-way communication systems to the electric grid to deliver safe and reliable service. This provides customers with tools and resources to manage their energy needs, reduces the environmental impact of electricity generation, reduces costs by efficiency and improved demand, and supports the interconnection and business models of third parties.
A tree that is a structural risk and could potentially strike electric supply lines when it falls.
When a customer’s power generation system (e.g. rooftop solar) is hooked up to a utility’s electricity grid, which allows power to be distributed both ways. When a customer creates more power than they need, the utility can share it with other customers across the grid, and when the same customer doesn’t generate enough for their own needs, the utility can ensure they have the power they need.
A billing unit for electricity delivery that equals the amount of energy you would use if you kept a 1,000-watt appliance running for one hour.
The generic term for any component of a circuit that consumes power or energy.
A foul-smelling but harmless, non-toxic chemical Unitil adds to natural gas that gives it a rotten egg smell. This safety measure makes it easier to detect a gas leak before it can create a hazardous situation.
The planned or unplanned unavailability of electric or natural gas service, due to maintenance, weather, equipment failure or other causes.
The highest power demand on an electrical grid over a specific period of time. An example of this would be during a hot, humid day when energy demand for cooling is high.
Renewable natural gas (RNG)
Natural gas that is derived from decomposing organic matter and is fully interchangeable with conventional natural gas.
A strip of land, usually about 30 to 50 feet wide, containing electric or gas transmission equipment.
An energy meter (such as electric or gas) that is able to provide real-time, detailed readings of the consumption in a home or building.
The voltage between the feet of a person who is standing near an energized grounded object, such as a downed wire or an energized, grounded tree limb. The difference in voltage between the person’s two feet creates a hazardous situation, as they can become a conduit for the electrical current if they attempt to move toward or away from the grounded object.
Scope 1 emissions
Greenhouse gas (GHG) emissions that are emitted from sources owned or controlled by an organization (e.g. burning of fuel for heat for a home or business).
Scope 2 emissions
Greenhouse gas (GHG) emissions that are associated with the consumption of electricity, steam, heat or cooling by an organization (e.g. electricity purchased for a home or business).
Scope 3 emissions
Greenhouse gas (GHG) emissions that are associated with activities from sources not owned or controlled by an organization, but are indirectly impacted by the organization in the value chain (e.g. products purchased and used by an organization).
A substation is a high-voltage electric system facility used to switch equipment and circuits or lines in and out of a distribution system. It also is used to transform voltage from high to low, or low to high.
A billing unit for natural gas delivery. One therm is equal to 100,000 BTUs (British Thermal Units), which is the quantity of heat needed to raise the temperature of one pound of water by one degree Fahrenheit, or 100 cubic feet of natural gas (CCF).
A metering method in which a utility company measures and charges a customer's energy consumption (price per kilowatt-hour) based on when the energy is used (time of day, week and year). For example, you might pay a higher rate if you are using electricity during a time of day when the demand on the system is high, such as a hot, humid day with heavy air conditioning load.
The voltage between an energized grounded object and the feet of a person who is in contact with the object. For example, a crane that contacts an energized power line would expose any person in contact with the crane to a touch potential.
The portion of electricity delivery that moves bulk electricity from larger generation sites over long distances to smaller, localized systems like sub-transmission or distribution circuits.
A device that changes electricity from one voltage to another. Transformers can be pole-mounted or housed in protective, ground-level cases referred to as padmounts.
A broad term that encompasses the work done by a utility’s forestry team with the goal of minimizing tree-related disruptions to customers’ service. This work includes tree pruning, hazard tree identification and removal, the use of herbicides and tree growth regulators, and management of incompatible plant species.
The “pressure” that drives an electric current between two points.
A basic unit of electric power equal to the amount of current (in amperes) multiplied by the amount of potential (in volts).
The practice (also known as weatherproofing) of protecting a building and its interior from the elements — particularly from sunlight, precipitation, and wind — and of modifying a building to reduce energy consumption and optimize energy efficiency. Some methods of improving the energy performance of a home include air sealing (closing gaps) and adding or installing insulation.