Regional Electric System

New England's Electric System

The high-voltage power system that forms the backbone of New England’s fully integrated electric system in 2015 traces its roots to the Great Northeast Blackout of 1965, which left 30 million customers in eight states without power.  The New England Power Pool was created in 1971 to centralize the dispatch of generation, schedule outages of generation and transmission equipment, and coordinate planning to improve reliability and economics.  In 1997, following actions by Congress and the Federal Energy Regulatory Commission, the Independent System Operator for New England (ISO New England) was established to operate the regional power system and implement wholesale power markets.  

ISO New England constantly balances electric supply and demand in the region, and it monitors, dispatches, and directs the flow of electricity every minute of every day.  The master control center in Holyoke, MA issues instructions to generators and transmission owners, dispatches power plants in order of the lowest supply offers, schedules delivery of the electricity through the high-voltage transmission lines, and continuously makes minor corrections to the system to maintain voltage and frequency within acceptable ranges.

"New England’s electric power grid has been planned and operated as a unified system of its participating transmission owners and market participants.  The New England system integrates resources with the transmission system to serve all regional load regardless of state boundaries.  Most of the transmission lines are relatively short and networked as a grid.  Therefore, the electrical performance in one part of the system affects all areas of the system.”  -- 2014 ISO New England Regional System Plan 

How Does the Regional Electric System Work?

The New England regional electric grid consists of 8,500 miles of high-voltage transmission lines that transport electricity from power generation plants to areas throughout the region that need electricity. Below you’ll find an example of how electricity flows from a hydropower plant to your home.

How Northern Pass Electricity will be Delivered

1. Hydropower generates electricity.
2. Electricity leaves the power plants and enters a nearby converter terminal where the voltage is increased to very high levels of Direct Current (DC) so that the electricity can be moved long distances throughout the electric system. (Later on, the power enters a second converter terminal where it is converted to Alternating Current (AC).
3. From the power plant substation, high-voltage electricity enters transmission lines, where it begins its journey to customers.
4. Before reaching your home, the high-voltage electricity is reduced at local substations so that it can travel…
5. …on the distribution lines that are often seen lining a street.
6. Power from the distribution lines enters a pole transformer where the voltage is reduced further to allow the electricity to safely enter your home.
7. A service line (either overhead or underground) carries the electricity from the pole transformer to…
8. … a meter on your property that measures how much electricity your family uses.
9. Finally the electricity passes through to a service panel inside the home, where it can then be distributed through wires that leads to outlets and switches.