Featured Articles-Grid Part 2

The New York State Electric Grid--Part 2

by Laura Burkhardt

Evolution of the Electric Power Grid

From Individual Utilities to Large Regional Systems. At the beginning of the 20^th century, more than 4,000 individual electric utilities operated in isolation from each other. As the demand for electricity grew, especially after World War II, utilities began to connect their transmission systems. These connections allowed utilities to share the economic benefits of building large and often jointly-owned electric generating units to serve their combined electricity demand at the lowest possible cost. Interconnection also reduced the amount of extra generating capacity that each utility had to have in order to ensure reliable service during times of peak demand. Over time, three large, interconnected systems evolved in the United States:

the Eastern Interconnection, covering the area east of the Rocky Mountains and a portion of the Texas panhandle;
the Western Interconnection, covering the area from the Rockies to the west;
the Electric Reliability Council of Texas (ERCOT), covering most of Texas.

The Eastern and Western Interconnections in the US are also linked with the Canadian power grid. The network structure of the interconnections provides multiple routes for power to flow and allows generators to supply electricity to many load centers. This redundancy helps prevent transmission line or power plant failures from causing interruptions in service to retail customers.

Deregulation. In the late 1990s many states, including New York, went through a process of electricity deregulation. Before this time utilities were vertically integrated, regulated monopolies; i.e., they owned and operated generation plants as well as transmission and distribution facilities. Under deregulation utilities were forced to become either electricity generators or electricity distributors; if the utility owned both generation and distribution plants it had to sell one or the other of these assets. For example, Central Hudson in Orange County chose to become a distributor and sold its Danskammer Generating Station in Newburgh to Dynegy in 2001 (followed in later years by a succession of other owners). Similarly, Con Edison also chose to become a distributor and sold its Indian Point Unit 1 and Unit 2 reactors to Entergy Nuclear Operations, Inc.; the New York Power Authority, which built Indian Point Unit 3, also sold its reactor to Entergy.

The Grid in New York State

By The Numbers. As we have described, the electricity grid in New York State is the system of interconnected energy infrastructure — power plants, transmission lines, transformers, substations, and distribution lines — that move power from suppliers to utilities and then to all New York residents and businesses. The following graphics illustrate the scope of the grid.




Terms & Abbreviations Megawatt (MW): A measure of electricity that is the equivalent of 1 million watts. It is generally estimated that a megawatt provides enough electricity to supply the power needs of 800 to 1,000 homes. Megawatt-Hour (MWh): A megawatt-hour is equal to one megawatt of energy produced or consumed continuously for one hour. Gigawatt (GW): A unit of power or capacity equal to one billion watts. Gigawatt-Hour (GWh): A gigawatt-hour is equal to one gigawatt of energy produced or consumed continuously for one hour. Load: A consumer of energy, or the amount of energy consumed. Load can also be referred to as demand. Capacity: Capacity is the maximum electric output that a generator can produce. It is measured in megawatts (MW). Generation: Generation is the amount of electric output that a generating station produces. It is expressed in megawatt-hours (MWh). It can also be referred to as supply. Nameplate Capacity: The maximum amount of electric output that any particular power source could produce. Generating stations typically run at something less than this maximum.
Graphics from Power Trends 2019, published by the New York Independent System Operator, copyright 2019. ([2-1], pg. 3) Terms & Abbreviations also from Power Trends 2019, pg. 70-74.

Managing the Grid: The New York Independent System Operator. New York’s electric grid is part of the Eastern Interconnection mentioned above that extends from Canada to Florida and from the Atlantic Ocean to the Rockies. The New York Independent System Operator (NYISO) is responsible for maintaining the safe, reliable flow of power throughout New York State. It was formed in 1997 and officially took control of New York's electric power system on December 1, 1999. NYISO is a not-for-profit corporation and is governed by an independent Board of Directors and a governance structure made up of committees, with market participants and stakeholders as members.

What NYISO does:

operates the state’s bulk electricity grid. NYISO coordinates the daily operations to distribute electricity supply and monitors the reliability of the system.
administers New York’s competitive wholesale electricity markets (see the sidebar)
conducts comprehensive long-term planning for the state’s electric power system, and
advances the technological infrastructure of the state’s electric system.