The Impacts of Wholesale Market Rules and Policies on Clean Energy Goals

A Primer for Local Governments

2. An Overview of RTOs

Wholesale electricity markets operated by RTOs and independent system operators (ISOs) cover two-thirds of electricity generation in the United States (FERC 2021c; Figure 1).1 These markets have a significant effect on the types and cost of generation resources that power the grid. RTOs help guide investment in new electricity sources, as well as the retirement of old ones, through their core responsibilities of operating markets for energy and grid services for maintaining reliability (ancillary services), and ensuring adequate generating capacity is available to serve loads (including the operation of markets for capacity in some RTOs). They also oversee transmission planning, which is a critical issue for the efficient operation of the grid and the development of utility-scale renewable resources.

A wholesale electricity market provides for the centralized dispatch of electricity from a diverse array of resources across a wide geographic area, which optimizes the dispatch of energy and reduces the costs of integrating renewables into the grid (Bromley-Dulfano et al. 2021; Gimon et al. 2020). Customers seeking clean energy offerings for their own electricity needs can benefit from participating in these markets—even where such energy is procured through a bilateral contract—because the markets reduce the costs of integrating renewable resources, provide transparent prices and a wider suite of ancillary services (Chen 2020), and facilitate the use of innovative contracts, such as virtual power purchase agreements (vPPAs), which provide additional options for purchasing clean energy (Energy Strategies 2021; Box 2). Moreover, these resources can access transmission in the RTO without needing a specific contract path (Energy Strategies 2021), and the RTOs conduct centralized transmission planning that is essentially nonexistent in non-RTO regions (Howe et al. 2021; Pfeifenberger et al. 2021). Such planning, in theory, would fully account for the future renewable resource development pursuant to public policies. Moreover, RTOs have been found to reduce the overall cost of electricity and the total need for generation (Chen and Hartman 2021).

Recent analyses of the impacts associated with the potential creation of an RTO where one does not presently exist, such as in the Southeast or the West, have shown significant benefits for the integration of renewable resources (Energy Strategies 2021; Gimon et al. 2020). However, the design of specific market rules and transmission planning processes can also either create barriers or opportunities for clean energy deployment, which vary by region.

Box 2 | Benefits of RTOs

  • Facilitate competition and grid access that allows a wider set of entities to sell or purchase power from the grid.
  • Centralize dispatch of electricity that optimizes integration and reduces costs.
  • Provide transparent prices that give more certainty to energy generators and buyers.
  • Offer a wide suite of ancillary services to support grid reliability.
  • Provide access to transmission without needing a specific contract path.
  • Conduct transmission planning that allows for stakeholder input and supports more holistic considerations.
  • Support more transparent governance and rules through publicly accessible processes in some regional transmission organizations and published tariffs.

RTO Responsibilities and Design Features

Figure 1 | ISO/RTO Territories in the United States

Notes: ISO = independent system operator. This map illustrates where organized wholesale markets have developed in the United States by indicating the territories of the regional transmission organizations (RTOs)/ISOs that operate them. The gray areas indicate locations where a fully developed organized wholesale market does not exist. For example, this map does not include the Western Energy Imbalance Market, operated by the California ISO (CAISO), as it is not a full RTO or ISO, though it provides a limited market for utilities in California, Washington, Oregon, Idaho, Montana, Wyoming, Nevada, Utah, Colorado, Arizona, and New Mexico to exchange power.

Source: Adapted from Schneider 2019.

All RTOs dispatch and operate markets for the purchase and sale of energy and ancillary services in two phases: a day-ahead market, which schedules the commitment of resources, and a real-time dispatch, which reconciles any differences in the day-ahead market and actual demand and supply.2 The RTO first dispatches the units with the lowest price offers to sell energy, and the highest offer needed to meet demand at that time sets the clearing price, which varies by location depending upon the availability of transmission to deliver energy from the resource with the lowest offer (FERC 2020). Generation owners may choose to self-schedule, whereby they are not incorporated into the RTO’s dispatch, which dispatches the lowest-cost generation available. This practice is not always problematic, but it can create inefficiencies when used by coal-fired generation, which typically must continue to operate at a minimum level of generation and cannot be easily turned on or off. Many of the plants that choose to self-schedule are owned by a utility, which will recover plant costs from ratepayers, denying utility customers the benefits of obtaining lower-cost energy from an RTO. Moreover, because it bypasses least-cost dispatch, coal self-scheduling can displace low-cost renewable energy within the overall grid mix (Daniel 2018, 2021). Ancillary services are needed to support the reliable operation of the grid and the transmission of energy; they are provided by qualifying generators and demand-side resources. These include such services as regulation (matching generation with very short-term changes in load) and reserves (needed to restore load and generation balance when a supply resource trips off-line). Some ancillary services are neither bought nor sold in the markets and instead are procured directly by the RTO (FERC 2020).

Several RTOs—ISO-NE, the NYISO, and PJM—run mandatory capacity markets, but MISO operates a voluntary capacity market.3 Capacity is the ability of a generator to produce energy or the ability of a customer (or group of customers) to reduce demand. A purchase of capacity provides an option to call on that resource to generate electricity or curtail their consumption (Gramlich and Goggin 2019).

A second critical set of RTO responsibilities includes regional transmission planning, allocating the costs of transmission, and coordinating with neighboring regions to determine opportunities for interregional transmission (FERC 2021a; Figure 2). Planning for and constructing transmission to deliver electricity is essential because generation resources, including solar and other renewables, are often located far from population centers. Although a significant amount of attention has been given to the need for RTO transmission planning improvements, there remains no effective regional planning in the non-RTO regions. For example, the Southeast has limited public participation and a lack of access to basic data, and the Western Interconnection generally only includes incumbent utilities’ transmission plans and does not consider independent developer projects or a more holistic assessment (Howe et al. 2021).

Figure 2 | Core Responsibilities of RTOs

Note: RTO = regional transmission organization.

Source: Authors.

RTO Goals and Mission Statements

The disconnect between the RTO market rules and procedures and the achievement of decarbonization can be seen in the tension between the goals and missions of the RTOs and those of the state governments, local governments, and corporations seeking to achieve bold decarbonization targets by procuring clean energy. The RTOs’ mission statements all incorporate two fundamental goals: ensuring grid reliability and providing competitive markets for electricity, with examples shown in Table 1. One exception is CAISO, which includes the state’s clean energy goals in its mission.

Table 1 | Mission Statements of RTOs

CAISO

“Will work with others in the industry to strike the balance between achieving the state’s clean energy goals and maintaining reliability, efficiency and affordability”

ERCOT

“Maintain system reliability; facilitate a competitive wholesale market; facilitate a competitive retail market; and ensure open access to transmission”

ISO-NE

Ensure “the constant availability of competitively-priced wholesale electricity”

MISO

“Enable reliable delivery of low-cost energy through efficient, innovative operations and planning”

NYISO

Ensure “a reliable, sustainable power grid and competitive markets”

PJM

“Ensure the safety, reliability and security of the bulk electric power system,” “understand customer needs and deliver valued service to meet those needs in a cost-effective manner,” “create and operate robust, competitive, and non-discriminatory electric power markets,” and “achieve productivity through the efficient union of superior knowledge workers and technology advances”

SPP

“Responsibly and economically keep the lights on today and in the future”

Notes: CAISO = California Independent System Operator; ERCOT = Electric Reliability Council of Texas; ISO-NE = Independent System Operator New England; MISO = Midcontinent Independent System Operator; NYISO = New York Independent System Operator; SPP = Southwest Power Pool.

Source: Collected from individual regional transmission organization and independent system operator websites, aggregated by WRI.

Clean energy advocates note that these RTO goals and mission statements should incorporate the achievement of state clean energy policies (NESCOE 2021; Turner et al. 2021a). The tension between these goals and the expansion of state decarbonization strategies was acknowledged by ISO-NE’s chief executive officer, Gordon van Welie, who recently stated that “efficiency and resource neutrality are prioritized in the wholesale electricity markets while state legislatures are requiring clean energy and decarbonization” (van Welie 2021). Moreover, with the exception of MISO, none of the RTOs includes transmission planning within its primary mission, which is somewhat incompatible with state clean energy goals, given the critical role of transmission in advancing the deployment of renewable energy across the country.

The misalignment of RTO goals and clean energy policies can be seen both in the development of market rules that pose direct impediments to the development of renewable energy (such as the Minimum Offer Price Rule discussed in Section 3) and in the general perception that the RTOs often are reluctant to adapt to newer, cleaner technologies and favor conventional resources (Gramlich 2021; Unel 2020; Welton 2021). Because states retain authority over generation resources, state policies should be fully accommodated by market rules and included in transmission planning. For example, in filing its revised capacity market rules, PJM noted that “state policies supporting certain resources within the PJM Region are a reality to be acknowledged” and such policies “are often designed to address externalities that are not accounted for in PJM’s wholesale markets” (PJM 2021, 7, 8).

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