A regional transmission organization (RTO) in the United States is an electric power transmission system operator (TSO) that coordinates, controls, and monitors a multi-state electric grid. The transfer of electricity between states is considered interstate commerce, and electric grids spanning multiple states are therefore regulated by the Federal Energy Regulatory Commission (FERC). [1] The voluntary creation of RTOs was initiated by FERC in December 1999. [2] The purpose of the RTO is to promote economic efficiency, reliability, and non-discriminatory practices while reducing government oversight.
An independent system operator (ISO) is similarly an organization formed at the recommendation of FERC. In the areas where an ISO is established, it coordinates, controls, and monitors the operation of the electrical power system, usually within a single US state, but sometimes encompassing multiple states. RTOs typically perform the same functions as ISOs, but cover a larger geographic area.
The two are similar, with an RTO being more clearly defined and born out of the concept of electrical grid reliability. The delineation between an ISO and an RTO is subtle to some and quite specific to others, as the similarities in the table below illustrate:
ISO | RTO |
---|---|
"...an organization formed at the direction or recommendation of the [FERC]..." | "...designated by the [FERC] to direct operation of the regional electric transmission grid in its area..." |
"...a neutral party responsible for the management and control of the electric transmission grid in a state or region..." | "...coordinates, controls and monitors an electricity transmission grid that is larger with much higher voltages than the typical power company's distribution grid..." |
"...operates an electric-transmission system that it does not own..." | "...coordinates power generation and transmission within an integrated regional market..." |
"...an independent, Federally regulated entity..." | "...an independent governing body..." |
"...ensure[s] the safety and reliability of the electric system..." | "...[responsible] for electric transmission grid operations, short-term electric reliability and transmission services within a multi-state region..." |
"...for the purpose of providing open access to retail and wholesale markets for supply..." | "...serve as the independent operator of the regional electric market..." |
In short, an ISO operates a region's electricity grid, administers the region's wholesale electricity markets, and provides reliability planning for the region's bulk electricity system. Today's RTOs do the same thing with an added component of greater responsibility for the transmission network, as established by the FERC.
"Independent System Operators grew out of Orders Nos. 888/889 where the Commission suggested the concept of an Independent System Operator as one way for existing tight power pools to satisfy the requirement of providing non-discriminatory access to transmission. Subsequently, in Order No. 2000, the Commission encouraged the voluntary formation of Regional Transmission Organizations to administer the transmission grid on a regional basis throughout North America (including Canada). Order No. 2000 delineated twelve characteristics and functions that an entity must satisfy in order to become a Regional Transmission Organization." [3] |
In April 1996, the Federal Energy Regulatory Commission (FERC) issued two orders that changed the landscape of how electricity is generated, transmitted, and distributed throughout the North America. Prior to these rulings, generated power and the subsequent energy provided to customers by local service providers was owned and controlled by single entities who often owned the entire generation, transmission, and distribution assets. Because these companies controlled the retail delivery of the energy from generation through their own power lines, consumers had little to no choice regarding whose electricity they were buying.
In economic terms, this structure constituted an impediment for new providers who would want to generate power, move energy, or provide retail electricity to individual consumers.
Order No. 888 [4] addressed "Promoting Wholesale Competition Through Open Access Non-discriminatory Transmission Services by Public Utilities; Recovery of Stranded Costs by Public Utilities and Transmitting Utilities." and Order No. 889 [5] added and amended existing rules "...establishing and governing an Open Access Same-time Information System (OASIS) (formerly real-time information networks) and prescribing standards of conduct."
Order No. 888 is often cited as the "Deregulation" of the electric industry. Deregulation, however, is not an accurate term. In actuality, the electricity industry is still regulated, depending on the region, by a series of federal, state, and local agencies and various public commissions. Order No. 888 is substantial in scope. Relative to this article, however, it defined two key elements:
"The legal and policy cornerstone of these rules is to remedy undue discrimination in access to the monopoly owned transmission wires that control whether and to whom electricity can be transported in interstate commerce. A second critical aspect of the rules is to address recovery of the transition costs of moving from a monopoly-regulated regime to one in which all sellers can compete on a fair basis and in which electricity is more competitively priced." [6] |
In addressing #1 above, Order No. 888 defined the fundamental purpose of an ISO to "…operate the transmission systems of public utilities in a manner that is independent of any business interest in sales or purchases of electric power by those utilities." [7] The order did not mandate or require the establishment of ISOs. Rather, in an attempt to comply with the FERC's order, groups of participants (or "Power Pools" composed of generators, transmission providers and utilities) partnered, and proposed to the FERC, for the right to establish designs of independent system operations. [7]
Through negotiation, collaboration and legal challenges, the first ISOs to emerge included California ISO, PJM Interconnection, New York ISO and New England ISO. [7] Each proposed a slightly different market design according to their collaborative results. In order to facilitate competitive wholesale markets, Order No. 888 specified the unbundling of a utility's operations separating generation and transmission and distribution.
"… all public utilities that own, operate or control interstate transmission facilities to offer network and point-to- point transmission services (and ancillary services) to all eligible buyers and sellers in wholesale bulk power markets, and to take transmission service for their own uses under the same rates, terms and conditions offered to others. In other words, it requires non-discriminatory (comparable) treatment for all eligible users of the monopolists' transmission facilities. The non-discriminatory services required by Order No. 888, known as open access services, are reflected in a pro forma open access tariff contained in the Rule. The Rule also requires functional separation of the utilities' transmission and power marketing functions (also referred to as functional unbundling) and the adoption of an electric transmission system information network." [7] |
In addressing #2 above, the original order (and subsequent clarification by the FERC) allows utilities, under certain defined circumstances, to seek extra-contractual recovery of stranded costs. The FERC continues to receive rehearing petitions regarding stranded cost recovery as it has clearly placed the importance on remedying what it terms as "undue discrimination" at the forefront. [7]
It is important to note that Order No. 888 was not met without objection among the public, academics and industry participants. Requests for rehearing and/or clarification were filed by 137 entities after the order's issuance. The majority agreed with the FERC's assertion for the need to harness the benefits of competitive electricity markets. [7]
Order No. 889 amended rules establishing and governing the Open Access Same-time Information System (OASIS) (formerly real-time information networks) and prescribed standards of conduct for its use and access. Subsequent orders provided clarifications, standards and protocols. [5]
"Under this final rule, each public utility (or its agent) that owns, controls, or operates facilities used for the transmission of electric energy in interstate commerce will be required to create or participate in an OASIS that will provide open access transmission customers and potential open access transmission customers with information, provided by electronic means, about available transmission capacity, prices, and other information that will enable them to obtain open access non-discriminatory transmission service. This final rule requires (1) each public utility subject to the rule to implement standards of conduct to functionally separate transmission and wholesale power merchant functions and (2) the creation of a basic OASIS system." [8] |
Where as Order No. 888 provided for an entity (an ISO) to facilitate open access, it was not written with the intent to establish one. FERC Order No. 2000 was:
"The Federal Energy Regulatory Commission (Commission) is amending its regulations under the Federal Power Act (FPA) to advance the formation of Regional Transmission Organizations (RTOs). The regulations require that each public utility that owns, operates, or controls facilities for the transmission of electric energy in interstate commerce make certain filings with respect to forming and participating in an RTO. The Commission also codifies minimum characteristics and functions that a transmission entity must satisfy in order to be considered an RTO." [9] |
Issued by the FERC on December 29, 1999, Order No. 2000 codified what it means to be an RTO including its minimum characteristics, functions and ratemaking policy. The order also stated its commitment toward open architecture with a stated goal that an RTO "...be designed so that they can evolve over time." [9] The order still, however, does not mandate that a new entity called an RTO be created, nor does it mandate that an entity call itself an RTO to comply with the FERC's order.
"In the Final Rule, we noted that the characteristics and functions could be satisfied by different organizational forms, such as ISOs, transcos, combinations of the two, or even new organizational forms not yet discussed in the industry or proposed to the Commission. Likewise, the Commission did not propose a "cookie cutter" organizational format for regional transmission institutions or the establishment of fixed or specific regional boundaries" [10] |
An ISO is an organization formed at the direction or recommendation of the Federal Energy Regulatory Commission (FERC). In the areas where an ISO is established, it coordinates, controls and monitors the operation of the electrical power system, usually within a single US State, but sometimes encompassing multiple states.
"The PJM, New England and New York ISOs were established on the platform of existing tight power pools. It appears that the principal motivation for creating ISOs in these situations was the Order No. 888 requirement that there be a single systemwide transmission tariff for tight pools. In contrast, the establishment of the California ISO and the ERCOT ISO was the direct result of mandates by state governments. The Midwest ISO, which is not yet operational, is unique. It was neither required by government nor based on an existing institution. Two states in the region subsequently required utilities in their states to participate in either a Commission-approved ISO (Illinois and Wisconsin), or sell their transmission assets to an independent transmission company that would operate under a regional ISO (Wisconsin)." [9] |
Similar to an RTO, the primary difference is that ISOs either do not meet the minimum requirements specified by FERC to hold the designation of RTO or that the ISO has not petitioned FERC for the status.
Electric utilities that are located within the United States and engage in interstate commerce fall under FERC authority. Not all utilities are members of ISOs. All utilities and ISOs are responsible to meet the compliance of a larger organization called the North American Electric Reliability Corporation (NERC), which overlays the entire FERC footprint and includes a Mexican utility and several Canadian utilities. As such, international reciprocity is commonplace, and rules or recommendations introduced by FERC often are voluntarily accepted by NERC members outside of FERC's jurisdiction. Therefore, one Canadian Province is a member of a US-based RTO, while two others function as an Electric System Operator (ESO), an organization essentially equal to a US-based ISO.
Within the United States one ISO, and its participating utilities, does not fall under FERC authority: The Electric Reliability Council of Texas (ERCOT). ERCOT falls under the authority of NERC and operates a reliability function, separate from its market function, in order to comply with NERC requirements.
ISOs act as a marketplace operator in wholesale power, resulting from FERC order No. 888. Most are set up as nonprofit corporations using governance models approved by FERC and/or regional or local commissions.
There are regions of the United States where ISOs do not exist. Consequently, the utilities do not engage in wholesale power markets. The Pacific Northwest, and states east of California and west of the Dakotas, Nebraska, Kansas and Texas largely do not participate. The majority of Southeastern states do not participate in wholesale markets. While these regions must conform to open access as mandated by FERC, the power exchanges between utilities is mostly facilitated through bilateral contracts and power purchase agreements.
There are nine ISOs within North America: [3] [11]
The New Brunswick System Operator (NBSO) was dissolved when New Brunswick's new Electricity Act went into effect in October 2013. [12]
An RTO is an organization formed at the approval of the Federal Energy Regulatory Commission (FERC). In the areas where an RTO is established, it coordinates, controls and monitors the operation of the electrical power system, usually within a single US State, but sometimes encompassing multiple states. The official definition for an RTO: "An entity that is independent from all generation and power marketing interests and has exclusive responsibility for grid operations, short-term reliability, and transmission service within a region." [13]
The designation of an RTO is largely one of scope. An organization wanting to achieve RTO status must petition the FERC for approval, and meet 4 minimum characteristics and 8 minimum functions: [9] [2]
Only electric utilities that are located within the United States fall under FERC authority, but a larger organization called the North American Electric Reliability Corporation (NERC) overlays the entire FERC footprint and also includes a Mexican utility and several Canadian utilities. As such, international reciprocity is commonplace, and rules or recommendations introduced by FERC often are voluntarily accepted by NERC members outside of FERC's jurisdiction. Therefore, one Canadian Province is a member of a U.S.-based RTO, while two others function as an Electric System Operator (ESO), an organization essentially equal to a U.S.-based ISO.
Some ISOs and RTOs also act as a marketplace in wholesale power, especially since the electricity market restructuring of the late 1990s. Most are set up as nonprofit corporations using governance models developed by FERC.
FERC Orders 888 and 889 defined how independent power producers (IPPs) and power marketers would be allowed fair access to transmission systems, and mandated the implementation of the Open Access Same-Time Information System (OASIS) to facilitate the fair handling of transactions between electric power transmission suppliers and their customers.
TSOs in Europe cross state and provincial borders like RTOs.
RTOs were created by the Federal Energy Regulatory Commission (FERC) as a way to handle the challenges associated with the operation of multiple interconnected independent power supply companies. FERC describes this as a voluntary system. The traditional model of the vertically integrated electric utility with a transmission system designed to serve its own customers worked extremely well for decades. As dependence on a reliable supply of electricity grew and electricity was transported over increasingly greater distances, power pools were formed and interconnections developed. Transactions were relatively few and generally planned well in advance.
In the last decade of the 20th century, some policy makers and academics projected that the electrical power industry would ultimately experience deregulation. RTOs were conceived as a way to handle the vastly increased number of transactions that take place in a competitive environment. About a dozen states decided to deregulate, but some pulled back following the California electricity crisis of 2000 and 2001.
RTOs ensure three key free marketer drivers: 1) open access and non-discriminatory services, 2) the continued reliability of a system unequaled anywhere else, and 3) multiple transmission charges that will not negate the savings to the end-use customer. Critics of RTOs counter that the wholesale electricity market as operated through the RTOs is in fact raising prices beyond what would obtain in a truly competitive situation, and that the organizations themselves add a needless layer of bureaucracy. While the original intention was for the RTOs to remain an independent, non-profit organization and were given nearly autonomous control of their service area. The primary committees, and a majority of participant committees are almost entirely represented by investor owned utilities and have eroded States power and Federal authority. [14]
The RTO concept provides for separation of generation and transmission and elimination of pancaked rates, and it encourages a diverse membership including public power. Wider membership contributes to the establishment of an entity with the size necessary to function as an RTO.
In the 1990s, as states and regions in the United States established wholesale competition for electricity, groups of utilities and their federal and state regulators began forming independent transmission operators that would ensure equal access to the power grid for non-utility firms, enhance the reliability of the transmission system and operate wholesale electricity markets. Today, seven of these grid operators, either independent system operators (ISOs) or RTOs, coordinate the power grid to ensure the reliable delivery of two-thirds of the electricity used in the United States to two-thirds of its population. Most are overseen by FERC.
ISOs and RTOs coordinate generation and transmission across wide geographic regions, matching generation to the load instantaneously to keep supply and demand for electricity in balance. The grid operators forecast load and schedule generation to assure that sufficient generation and back-up power is available in case demand rises or a power plant or power line is lost. They also operate wholesale electricity markets that enable participants to buy and sell electricity on a day-ahead or a real-time spot market basis. These markets provide electricity suppliers with more options for meeting consumer needs for power at the lowest possible cost.
ISO/RTOs provide non-discriminatory transmission access, facilitating competition among wholesale suppliers to improve transmission service and provide fair electricity prices. Across large regions, they schedule the use of transmission lines; manage the interconnection of new generation and monitor the markets to ensure fairness and neutrality for all participants. Providing these services regionally is more efficient than providing them on a smaller-scale, utility by utility.
Today's power industry is far more than a collection of power plants and transmission lines. Maintaining an effective grid requires management of three different but related sets of flows – the flow of energy across the grid; the exchange of information about power flows and the equipment it moves across; and the flow of money between producers, marketers, transmission owners, buyers and others. ISO/RTOs play an essential role in managing and enhancing all three of these flows.
As of 2023 there are ten ISO/RTOs operating in North America: [15] [16]
Non-RTO transmission organizations:
ColumbiaGrid, a nonprofit corporation, is not a regional transmission organization (RTO) and has no plans to become one, but instead seeks to achieve many of the benefits of an RTO through incremental additions to its functions. ColumbiaGrid was formed after some of its members chose not to continue in efforts to form Grid West, a Northwest evolutionary structure with the ability to add functions and to move toward independent grid management. The ColumbiaGrid members, including the Bonneville Power Administration, several Washington State public utilities and two investor-owned utilities, wanted an organization with more limited functions and no independent ability to change. ColumbiaGrid performs single-utility transmission planning and expansion via an open and transparent process and is also establishing a multi-system OASIS portal.
The former Grid West participants who had argued for an eventual RTO, mainly investor-owned utilities and state representatives from Oregon, Idaho, Montana, Wyoming and Utah, formed the Northern Tier Transmission Group (NTTG), a nascent effort open to evolution but initially focused on inexpensive and relatively easy improvements to grid management, including area control error (ACE) diversity interchange, currently underway; transparent methodologies for calculating available transmission capacity; and planning, as required by FERC Order 890.
International:
General:
The Federal Energy Regulatory Commission (FERC) is an independent agency of the United States government that regulates the interstate transmission and wholesale sale of electricity and natural gas and regulates the prices of interstate transport of petroleum by pipeline. FERC also reviews proposals to build interstate natural gas pipelines, natural gas storage projects, and liquefied natural gas (LNG) terminals, in addition to licensing non-federal hydropower projects.
The North American Electric Reliability Corporation (NERC) is a nonprofit corporation based in Atlanta, Georgia, and formed on March 28, 2006, as the successor to the North American Electric Reliability Council. The original NERC was formed on June 1, 1968, by the electric utility industry to promote the reliability and adequacy of bulk power transmission in the electric utility systems of North America. NERC's mission states that it "is to assure the effective and efficient reduction of risks to the reliability and security of the grid".
A public utility company is an organization that maintains the infrastructure for a public service. Public utilities are subject to forms of public control and regulation ranging from local community-based groups to statewide government monopolies.
An electricity market is a system that enables the exchange of electrical energy, through an electrical grid. Historically, electricity has been primarily sold by companies that operate electric generators, and purchased by consumers or electricity retailers.
The electric power industry covers the generation, transmission, distribution and sale of electric power to the general public and industry. The commercial distribution of electric power started in 1882 when electricity was produced for electric lighting. In the 1880s and 1890s, growing economic and safety concerns lead to the regulation of the industry. What was once an expensive novelty limited to the most densely populated areas, reliable and economical electric power has become an essential aspect for normal operation of all elements of developed economies.
The Open Access Same-Time Information System (OASIS), is an Internet-based system for obtaining services related to electric power transmission in North America. It is the primary means by which high-voltage transmission lines are reserved for moving wholesale quantities of electricity. The OASIS concept was originally conceived with the Energy Policy Act of 1992, and formalized in 1996 through Federal Energy Regulatory Commission (FERC) Orders 888 and 889.
A transmission system operator (TSO) is an entity entrusted with transporting energy in the form of natural gas or electrical power on a national or regional level, using fixed infrastructure. The term is defined by the European Commission. The certification procedure for transmission system operators is listed in Article 10 of the Electricity and Gas Directives of 2009.
The Texas Interconnection is an alternating current (AC) power grid – a wide area synchronous grid – that covers most of the state of Texas. The grid is managed by the Electric Reliability Council of Texas (ERCOT).
Southwest Power Pool (SPP) manages the electric grid and wholesale power market for the central United States. As a regional transmission organization, the nonprofit corporation is mandated by the Federal Energy Regulatory Commission to ensure reliable supplies of power, adequate transmission infrastructure and competitive wholesale electricity prices. Southwest Power Pool and its member companies coordinate the flow of electricity across approximately 60,000 miles of high-voltage transmission lines spanning 14 states. The company is headquartered in Little Rock, Arkansas.
A NERC Tag, also commonly referred to as an E-Tag, represents a transaction on the North American bulk electricity market scheduled to flow within, between or across electric utility company territories. The NERC Tag is named for the North American Electric Reliability Corporation (NERC), which is the entity that was responsible for the implementation of the first energy tagging processes. NERC Tags were first introduced in 1997, in response to the need to track the increasingly complicated energy transactions which were produced as a result of the beginning of electric deregulation in North America.
The Midcontinent Independent System Operator, Inc., formerly named Midwest Independent Transmission System Operator, Inc. (MISO) is an Independent System Operator (ISO) and Regional Transmission Organization (RTO). It provides open-access transmission service and monitors the high-voltage transmission system in the Midwestern United States, in Manitoba, Canada, and in a southern U.S. region that includes much of Arkansas, Mississippi, and Louisiana. MISO also operates one of the world's largest real-time energy markets. The 15 states covered by MISO are: Arkansas, Illinois, Indiana, Iowa, Kentucky, Louisiana, Michigan, Minnesota, Mississippi, Missouri, Montana, North Dakota, South Dakota, Texas, and Wisconsin.
ISO New England Inc. (ISO-NE) is an independent, non-profit regional transmission organization (RTO), headquartered in Holyoke, Massachusetts, serving Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont.
PJM Interconnection LLC (PJM) is a regional transmission organization (RTO) in the United States. It is part of the Eastern Interconnection grid operating an electric transmission system serving all or parts of Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and the District of Columbia.
There is a large array of stakeholders that provide services through electricity generation, transmission, distribution and marketing for industrial, commercial, public and residential customers in the United States. It also includes many public institutions that regulate the sector. In 1996, there were 3,195 electric utilities in the United States, of which fewer than 1,000 were engaged in power generation. This leaves a large number of mostly smaller utilities engaged only in power distribution. There were also 65 power marketers. Of all utilities, 2,020 were publicly owned, 932 were rural electric cooperatives, and 243 were investor-owned utilities. The electricity transmission network is controlled by Independent System Operators or Regional Transmission Organizations, which are not-for-profit organizations that are obliged to provide indiscriminate access to various suppliers to promote competition.
The California Independent System Operator (CAISO) is a non-profit Independent System Operator (ISO) serving California. It oversees the operation of California's bulk electric power system, transmission lines, and electricity market generated and transmitted by its member utilities. CAISO is one of the largest ISOs in the world, delivering 300 million megawatt-hours of electricity each year and managing about 80% of California's electric flow.
The electrical power grid that powers Northern America is not a single grid, but is instead divided into multiple wide area synchronous grids. The Eastern Interconnection and the Western Interconnection are the largest. Three other regions include the Texas Interconnection, the Quebec Interconnection, and the Alaska Interconnection. Each region delivers power at a nominal 60 Hz frequency.
Resource adequacy in the field of electric power is the ability of the electric grid to satisfy the end-user power demand at any time. RA is a component of the electrical grid reliability. For example, sufficient unused generation capacity shall be available to the electrical grid at any time to accommodate major equipment failures and drops in variable renewable energy sources. The adequacy standard should satisfy the chosen reliability index, typically the loss of load expectation (LOLE) of 1 day in 10 years.
A regional entity (RE) in the North American power transmission grid is a regional organization representing all segments of the electric industry: electric utilities, federal agencies, independent power producers, power market operators, and end-users of the energy. North American Electric Reliability Corporation (NERC) delegates to REs authority to enforce reliability standards, collectively REs, together with NERC, are known as an "ERO Enterprise".
The Western Resource Adequacy Program (WRAP) is an electricity planning and sharing agreement between electric utilities of the Western Power Pool. Its goals are to improve regional reliability and adequacy while decreasing costs by moving utilities from an individual utility framework to a regional approach. Program operations are based in Oregon.