Federal Energy Regulatory Commission

Working Paper on Standardized Transmission Service

and Wholesale Electric Market Design

                                                                                               

                       

                                                                             

            To enhance competition in wholesale electric markets and broaden the benefits and cost savings to all wholesale and retail customers, the Commission intends to reform public utilities’ open access tariffs to reflect a standardized wholesale market design.  The goals of this initiative are to:  provide more choices and improved services to all wholesale market participants; reduce delivered wholesale electricity prices through lower transactions costs and wider trade opportunities; improve reliability through better grid operations and expedited infrastructure improvements; and to increase certainty about market rules and cost recovery for greater investor confidence to facilitate much-needed investments in this crucial economic sector.  A key challenge will be to balance the need for standardization for a seamless transmission grid with streamlined operations and costs with the need to permit regional differences and market innovation.

 

            The Commission is conducting this effort through Docket No. RM01-12-000 and plans to issue a notice of proposed rulemaking, containing a reformed open access transmission tariff, this summer.  The reformed tariff will be filed by regional transmission organizations (RTOs) and other public utilities that own, operate or control interstate transmission facilities.       

 

            The Commission’s Order Nos. 888 and 889 established non-discriminatory open access transmission services and stranded cost recovery rules for the transition to competitive markets.  These rules established a sound foundation for competitive bulk power markets in the United States, but did not address every issue now before us.  There is wide consensus today about the need to update the pro forma tariff and the basic elements of wholesale electric market design.  On some issues, there is clear consensus about what needs to be done; on others, further policy decisions are needed to move forward.  The Commission intends this paper to offer that policy guidance and allow the parties to move forward in a focused process that builds upon Order Nos. 888 and 889, and the institutional innovations of RTOs identified in Order No. 2000, to complete the establishment of robust, seamless competitive wholesale electric markets.

 

            Based on dialogue with a wide array of stakeholders and state commissioners over the past few months, this paper lays out principles and policy decisions on the standard market design to guide the Commission in developing a revised transmission tariff.  Most of these reflect consensus voiced by the parties in written comments and in the conferences and workshops held by the Commission with the industry between October 2001 and February 2002.  These policy calls are subject to further dialogue with and comment from participants.  The Commission will issue a notice of proposed rulemaking this summer and all affected parties will be able to further comment on the notice of proposed rulemaking.  The Commission will consider all comments in determining the final rule.

 

            Attached hereto is an Appendix that responds to a number of questions on market design from the Electronic Scheduling Collaborative.

 

A.  The Need for a Single Transmission Tariff

 

            Order Nos. 888 and 889 established the foundation needed to develop competitive bulk power markets.  However, it has become clear that the Order No. 888 open access transmission tariff (OATT) contains provisions that, in practice and in conjunction with market design rules that currently exist in the electric utility industry, allow energy suppliers that also provide transmission service to favor their own generation and disadvantage other energy suppliers.  For example, a vertically integrated utility determines available transmission capability and the facilities necessary to interconnect a new generator.  In both cases, the transmission provider has the incentive to favor its own generation.  This creates barriers for other energy providers, raises costs from inefficiency for all grid operations, and often results in higher delivered energy prices to end-use customers.  The lack of regional coordination of the grid (for instance, the calculation of Available Transmission Capacity and Total Transmission Capacity on a company basis) contributes to inefficient operations by causing unnecessary transmission congestion and transaction curtailments.  In addition, market design issues not addressed by the current tariff impede a seamless national transmission grid and the development of broad, fully competitive electricity markets.

 

            At present there is no single set of rules governing transmission of electric energy. The electrons moving across the grid do not distinguish between bundled retail and other services, and behave according to the laws of physics rather than the laws of a particular jurisdiction.  With more non-integrated electricity suppliers and a deeper reliance on wholesale electric markets, there are substantial competitive consequences and higher costs to all retail customers if we do not apply consistent, non-discriminatory rules to all transmission customers.  To protect all customers and assure the benefits of competition for all, consistent transmission rules must be applied.

                       

            The existing tariff reveals different flaws in different regions of the country.  In areas where most energy transactions occur through bilateral contracts without centralized spot markets for energy and ancillary services, more and more transactions are being curtailed under transmission loading relief (TLR) mechanisms that rely on non-price allocation methods.  In these cases, congested transmission capacity is not being consistently allocated to the market participants who value transmission the most. 

 

            Market design flaws are visible in every regional electric market today under the existing tariff.  These flaws are allowing operational problems such as the “socialization” or “uplift” of congestion management prices across all customers in a region, which obscures the potential for price signals to indicate where new generation, demand response or transmission is needed.  In other regions, high fees are being collected for the value of generation capacity that do not clearly incent the construction of new capacity.  A third type of flaw has been the sequential clearing of energy and ancillary service markets, which fails to deliver efficient prices for the service delivered.  No region has been exempt from market design flaws of one type or another.

 

            Even where market designs appear to be very similar in contiguous regions, "seams" problems have persisted.  A seams problem occurs when differences in business practices, market design, reliability rules, or software platforms between regions impedes trade between the regions.  When these seams problems prevent the economic exchange of energy, they increase transactions costs.

 

            Even within a region, a poorly designed or inefficiently managed transmission system can result in significant increased costs to customers.  It is useful to review the approximate costs of electric generation and transmission to see the impact that transmission can have on energy costs.  Consider these approximate costs as viewed by retail customers (excluding distribution and load-serving entities' (LSEs) operating costs, which represent about 15% or less of the average retail bill) for two regional markets, for the year 2000:[1]

 

 

 

PJM

NY

 

$ Millions

% of Total Cost

$ Millions

% of Total Cost

Energy Costs

$9,822

92.2%

$7,599

88.6%

    Congestion Costs

$134

1.2%

$1,209

14.1%

    Line Losses

$491

4.5%

$380

4.5%

Transmission

Revenue Requirement

$832

7.8%

$979

11.4%

Total Cost

$10,654

100%

$8,578

100%

Peak Load (MW)

49,417

30,200

 

            These markets are used because we have information readily available for them.  These figures illustrate several important points.  First, within the delivered retail bill, the cost of transmission alone is small compared to the cost of generation, but these costs are still large in absolute terms.  Second, two elements which are substantially affected by the design and operation of the transmission system have a significant effect on energy costs, i.e., the cost of transmission congestion (which is actually the opportunity cost of having too little transmission) and the cost of line losses (the additional generation that must be produced to make up for energy lost in the delivery of electrons through the grid, averaging about 5% of total electricity produced).  Third, the costs hint at the substitutability between generation and transmission – specifically, as the grid becomes constrained, energy costs rise markedly due to the redispatch of more expensive plants to work around the transmission constraints.  This can be seen in the higher congestion costs in New York caused by the unavailability of the Indian Point nuclear plant in the summer of 2000.  Additions to the grid may slightly increase the transmission revenue requirement but yield large reductions in total energy cost per kWh from lower congestion costs and greater access to cheaper bulk power sources.

 

            The table above shows the relative costs of energy and transmission within two areas that have markets designed similarly to the standard market design proposed here.  In other areas, where transmission constraints are not managed with similar mechanisms, the impact of congestion on energy costs is likely far greater.  Adoption of a standard market design in those areas would improve price signals and encourage more efficient expansion of the transmission grid with corresponding reductions in energy costs.  Even if the energy costs reductions are small in percentage terms, there could still be large savings in absolute terms.

 

            In Order No. 2000, the Commission recognized the need to make further changes to its regulations to address these inefficiencies and discrimination problems.  However, Order No. 2000 primarily dealt with the structure and independence of the new RTOs.  It did not directly address the market rules that were needed to achieve the objective of competitive electric wholesale markets.

 

            We must act now to remedy any undue discrimination and unjust and unreasonable pricing caused by the problems highlighted above and to achieve the reliability and cost-saving benefits of competition.  We must restructure electric transmission service to provide comparability for all sellers of electricity, use transmission assets more efficiently, and reduce inefficiencies by standardizing market rules.  This should be done by creating a new, flexible transmission service to be offered by all transmission providers to all customers, with a new standard market design for wholesale electric markets.

 

            To assure fairness and transparency for all participants, an entity independent of the market participants must administer the imbalance energy markets that are to be part of the standard market design proposed here.  As described below, the Commission is proposing to use Locational Marginal Pricing (LMP) as the system for congestion management.  Under LMP, the imbalance and transmission markets must operate together.  Thus, it is more efficient to have one entity perform the two functions identified by NERC in its new Functional Model as the Balancing Authority and the Transmission Service Provider.  In this document, we use the term "transmission provider" for the independent entity that would perform functions including accepting and processing requests for transmission service, administering the OASIS, scheduling transactions, and administering the imbalance markets.  Thus, an RTO or independent system operator (ISO) would meet the definition of transmission provider.  However, vertically-integrated public utilities who are not part of an RTO or ISO would have to contract with an independent entity to serve as the "transmission provider" to perform these functions.  The question of whether an independent transmission company, i.e., one that has no affiliation with a generator or power marketer, qualifies as a transmission provider requires further consideration.

 

B.  General Principles for Standard Market Design 

 

            The lessons learned in existing markets lead us to establish a set of principles to guide the development of standard market design:      

                       

1.         The objective of standard market design for wholesale electric markets is to establish a common market framework that promotes economic efficiency and lowers delivered energy costs, maintains power system reliability, mitigates significant market power and increases the choices offered to wholesale market participants.  All customers should benefit from an efficient competitive wholesale energy market, whether or not they are in states that have elected to adopt retail access.

 

2.         Standardization of market design and business practices reduces transaction costs and reduces "seams issues" that restrict trading.  In developing and implementing standard market design, the maximum benefit will be gained by standardizing as much as practicable.  Deviations or changes from the standards must be consistent with or superior to standard market design.  Such changes must also be compatible with neighboring systems to prevent seams issues.

 

3.         Market rules and market operation must be fair, well defined and understandable to all market participants.

 

4.         Imbalance markets and transmission systems must be operated by entities that are independent of the market participants they serve.

 

5.         Energy and transmission markets must accommodate and expand customer choices.  Buyers and sellers should have options which include self-supply, long-term and short-term energy and transmission acquisitions, financial hedging opportunities, and supply or demand options.

 

6.         Market rules must be technology- and fuel-neutral.  They must not unduly bias the choice between demand or supply sources nor provide competitive advantages or disadvantages to large or small demand or supply sources.  Demand resources and intermittent supply resources should be able to participate fully in energy, ancillary services and capacity markets.

 

7.         Standard market design should create price signals that reflect the time and locational value of electricity.  The price signal – here, created by LMP – should encourage short-term efficiency in the provision of wholesale energy and long-term efficiency by locating generation, demand response and/or transmission at the proper locations and times.  But while price signals should support efficient decisions about consumption and new investment, they are not full substitutes for a transmission planning and expansion process that identifies and causes the construction of needed transmission and generation facilities or demand response.

 

8.         Demand response is essential in competitive markets to assure the efficient interaction of supply and demand, as a check on supplier and locational market power, and as an opportunity for choice by wholesale and end-use customers.

 

9.         Transmission owners will continue to have the opportunity to recover the embedded and new costs of their transmission systems.  Consistent with current policy, merchant transmission capacity would be built without regulatory assurance of cost recovery.

 

10.       Customers under existing contracts (real or implicit) should continue to receive the same level and quality of service under standard market design.  However, transmission capacity not currently used and paid for by these customers must be made available to others.

 

11.       Standard market design must not be static.  It must not inhibit adaptation of the market design to regional requirements nor hinder innovation.

 

C.  The New Transmission Service

 

            Transmission providers should be required to offer a nondiscriminatory, standard transmission service, "Network Access Service," for all customers, including vertically integrated utilities.  Network Access Service would combine features of both of the existing open access transmission services, the flexibility and universal access of network integration transmission service and the reassignment rights of point-to-point service.  This allows all customers to have a system of tradable transmission property rights that will expand their transmission options and enable and enhance competition in wholesale electric markets.  All transmission services should be performed under a single set of market rules.

 

            To complement Network Access Service and implement the standard market design, transmission providers should manage congestion using LMP.  To handle imbalances and the procurement of ancillary services, the transmission provider would operate markets for energy, regulation and operating reserves in conjunction with the markets for transmission services.  These markets would be bid-based markets operated in two time frames: (1) a day ahead of real-time operations, and (2) in real time.  For both the day-ahead and real-time time frames, the transmission provider would assure that purchases and sales of energy, regulation and operating reserves through the centralized energy, regulation and operating reserves markets, or through self-supply or bilateral contract, are coordinated with transmission services on the grid.  The transmission provider would establish schedules for transmission service, and sales and purchases of energy, regulation and operating reserves, to ensure the most efficient use of the transmission grid.

 

            Network Access Service

 

            Network Access Service would give the customer the right to transmit power between two points, a source and a sink.  A source is defined here as the location where a transaction originates, and a sink is defined as the location where a transaction terminates.  Sources and sinks would be defined to include both individual nodes as well as aggregated points such as trading hubs.  Thus, a Network Access Service customer could use this service to move power from a generator (source) to a load (sink), from a generator (source) to a trading hub (sink), from one trading hub to another, or from a trading hub (source) to a load (sink).  A Network Access Service customer would have access to all sources and sinks on the system.  An access charge would be used to recover the embedded costs of the transmission system.  The manner in which embedded costs will be recovered requires further discussion to be resolved.

 

            Some transactions cannot occur without causing congestion on the transmission system.  Network Access Service gives customers two options for how to handle the costs of this congestion, either: (1) a predetermined price, using "transmission rights," or (2) the applicable congestion charge in which the customer bears the full cost of congestion management.  The issue of how to allocate transmission rights is difficult and contentious.  However, our intent is to preserve the existing rights of current users of the system.  

 

            Transmission rights for transmission price certainty

 

            A customer can achieve price certainty for Network Access Service by acquiring transmission rights.  A transmission right allows the customer to schedule power from specific source(s) and sink(s) without having to pay congestion for service between those points.  Anyone can hold a transmission right.  A key implementation issue will be the initial assignment of transmission rights.  One option is to directly allocate the transmission rights to customers that pay the embedded costs of the system.  Any transmission rights not claimed by these customers would be auctioned.  Another option would be to conduct an auction to apportion the transmission rights, with the proceeds from the auction allocated to those customers that pay the embedded costs of the system.

 

            However transmission rights are initially issued, transmission rights holders can sell them into a secondary market so that others can buy transmission price certainty.  If a transmission rights holder chooses not to schedule transmission service at a particular time, the transmission capacity will be made available to the market and the transmission rights holder will receive the associated congestion revenue.

 

            The transmission provider must offer to sell transmission rights for all of the capacity on the grid, but it cannot sell more rights than the capacity can accommodate.   After the initial allocation of transmission rights, there may need to be a regular reallocation of the transmission rights or the auction revenues to reflect changes in load responsibilities due to retail unbundling or other factors.  Over the long term, if a customer (or merchant transmission company) pays to construct new transmission facilities that add transfer capability, the entity that pays for the construction, whether a customer or transmission owner, should receive the transmission rights associated with the new transfer capability (unless they receive credits against the Network Access Service access charge).  This issue needs further consideration.

 

            Transmission without price certainty

 

            The alternative to predetermined transmission prices under transmission rights is for the Network Access Service customer to schedule service by agreeing to pay for any congestion costs of a particular transaction.  Congestion costs occur when the capacity of the grid is limited and it is not possible to transfer more energy across the grid from the customer's intended source to sink without compromising grid reliability.  In this situation, the transmission provider will redispatch a more expensive generator on the other side of the constraint to deliver to the intended sink.  The incremental cost of this "out-of-merit" redispatch is charged to customers who have not secured transmission

rights.  Customers who hold transmission rights would not be charged the redispatch costs.

 

            Day-ahead scheduling       

 

            Every day, the transmission operator would develop a schedule for use of the transmission system for each hour of the next day.  The schedule would accommodate the requests of customers with transmission rights and those without, as well as transmission needed for delivery of purchases and sales made through the centralized energy spot market (described further below).  Customers with transmission rights who want transmission service between their designated source and sink points would schedule their desired service between those specific points, and would be charged for losses but not congestion.  Customers without transmission rights (including the transmission provider on behalf of customers purchasing or selling through the centralized energy spot market) would also schedule transmission service, by agreeing to pay the costs of losses and congestion between the desired source and sink points.  Transmission rights are either source-and-sink-specific or flowgate-specific (discussed below).  If a customer with transmission rights for a specific source-sink pair (from A to B) wants transmission service between a different set of source and sink points (from C to B), the customer would need to pay the cost of congestion and losses for transmission service between those new points (C to B).

 

            Through the scheduling process, customers will be able to react to price signals by indicating how prices affect their demand for transmission service.  In requesting transmission service, customers without transmission rights could either:  (1) submit a bid stating the maximum congestion charge they are willing to pay for transmission service, or (2) indicate that they desire transmission service regardless of the price.  Customers with transmission rights could voluntarily submit bids indicating the price above which they are willing to reduce their purchases of transmission service in exchange for receiving congestion revenues.  For example, a customer with transmission rights from A to B may prefer receiving the congestion revenues if the congestion costs between those points is over $150 per MWh.  In that case, the customer would voluntarily reduce its demand (for example, through a demand-side response program) for transmission service between those points.

 

            If there is sufficient transmission capacity to accommodate all requested transmission service, then all requests would be scheduled, and all scheduled customers would pay a charge to recover the applicable cost of losses.  However, if the amount of transmission service desired along one or more transmission paths exceeds the transmission capacity (thereby resulting in transmission congestion), then the charge for using each congested path would be raised sufficiently (based on the cost of redispatch and the price bids for transmission service) to alleviate the congestion by reducing the demand for transmission service.  The added charge would be paid only by customers without transmission rights along the desired transmission path (or flowgate).  As noted above, a transmission rights holder would receive congestion revenues when the path (or flowgate) is congested and the transmission rights holder elects not to schedule all or a portion of its rights.

 

            Real-time transactions

           

            Once all day-ahead transactions have been scheduled, any remaining transmission capacity will be made available for real-time transactions.  Transactions that were not scheduled a day ahead would flow at a charge that covers the applicable cost of losses and any congestion associated with necessary redispatch.  A customer with transmission rights between a specific source and sink that did not schedule transmission service between those points a day ahead could still obtain transmission service in real time.  In that case the customer would pay the real-time congestion costs and losses.  The customer would also receive the congestion revenues from the day-ahead market for those points.

 

            Additional features of the standard transmission service

 

            Transmission prices (to recover congestion and losses) developed in the transmission market must be consistent with locational energy prices developed in the energy market.  A locational energy price equals the delivered cost of electricity to that point, which equals the sum of the energy price plus its congestion cost plus the value of transmission line losses from the source to the sink.  The difference in energy prices between two locations should equal the transmission price that will be paid by customers without transmission rights to transmit power between these two points.

 

            Transmission rights can be defined in two ways:  (1) source-to-sink rights, and (2) flow-based, or flowgate, rights.  Both source-to-sink and flowgate rights are direction-specific (i.e., a right in one direction is different from a right in the opposite direction).  A source-to-sink right is specified by a source (which can be a generator node, an aggregation of generator nodes, an interface, or a trading hub) and a sink (which can be a delivery node, an aggregation of delivery nodes, an interface, or a trading hub), and the total MW that are to be injected and withdrawn from the system at a point in time.  It entitles the holder to schedule transmission of the specified MW of energy in the day-ahead market from the source to the sink without paying congestion charges.  To the extent that the holder does not schedule its full MW entitlement, the holder is entitled to collect the congestion revenues from the source to the sink for the unscheduled capacity.

 

            A flowgate right is specified by the total MW capacity over a particular transmission facility (or group of facilities, e.g., an interface) rather than just the source and sink points.  It entitles the holder to receive the congestion revenue associated with the specified MW flow over the identified transmission facility in the specified direction.[2]

 

            Transmission rights can be specified as obligations or options.  An obligation requires the customer either to (a) physically transmit energy from its source to its sink points, or (b) receive the congestion revenues (either positive or negative) between the points.  An option gives the customer the entitlement to transmit energy or collect the congestion revenues, but the customer has no obligation to do either.[3]  Currently, the transmission rights offered in ISOs that use LMP are obligations, although there is customer interest for transmission rights that are options.  Existing firm point-to-point transmission contracts are similar to transmission rights that are options.  At the start of Network Access Service, the transmission provider must offer source-to-sink obligations.  Upon the request of market participants, the transmission provider must also offer source-to-sink options and flowgate rights as soon as it is technically feasible.

 

D.  Energy Market Design

 

            One of the problems under the current OATT is the treatment of imbalances.  The current rules give a competitive advantage to control area operators because they allow the operator to net out its imbalances over a large load and operate a number of power plants, while charging other sellers and buyers penalties for imbalances.  The remedy for these problems is a balancing market with imbalances charged the real-time price for any excess or deficiency of energy. 

 

            Unlike gas pipeline systems, electric systems must balance supply and demand in real time.  In electric networks, this balance is generally achieved by adjusting generator settings (energy production) rather than controls on the electric transmission network itself (as is done for the gas transmission system).  Additionally, electric systems are affected by the operation of other electric systems in the interconnection (i.e., loop flow and parallel flows as externalities affecting all transactions on the grid), while gas pipelines rely on controls on the gas transmission network to balance supply and demand and do not face significant interaction and interdependency effects.

 

            These differences in the operations of the systems argue for different systems for handling imbalances.  On a gas system with storage, a small daily imbalance may have little or no operational effect and not threaten service to other customers.  But on an electric transmission system, a similar imbalance could threaten service reliability unless the imbalance can be cured in real time.  Consequently, while there is no need for centralized regional coordination on a gas system, such a need exists for an electric system, and that coordination is best effected using a real-time market for energy.  Such a real-time market will improve system efficiency and lower costs relative to the requirements of Order Nos. 888 and 889.

 

            While a day-ahead market is not strictly necessary for resolving imbalances, experience has shown that the combination of a day-ahead market and real-time market enhances system reliability and efficiency compared to operating only a real-time market.  The day-ahead market lets the system operator ensure that sufficient generating units and transmission elements are committed to serve the next day's load.  The day-ahead market also provides the opportunity for a generator's bids to better reflect the operational constraints and costs of generating units through multi-part bidding.  Additionally, the day-ahead market provides better scheduling opportunities for the demand side to participate in the market.  Markets that have operated with both a real-time and day-ahead market are more efficient than those with only a real-time market.

 

Day-Ahead Energy Market

 

            The transmission provider must operate a day-ahead market in order to develop a joint day-ahead schedule for transmission service, energy, and ancillary services.  The day-ahead schedule will be developed so as to maximize the combined economic value of transmission service, energy, and ancillary services, based on the bids submitted. 

 

            The energy market component of the day-ahead market performs two functions – through bids evaluated at auction, the market selects those units to be run in the next day and sets the energy prices to be paid in each hour for that energy.  Those unit commitments are coordinated with the transmission scheduling operation to assure that energy can be delivered from the generation point to the delivery point, in a secure and reliable fashion.

 

General Features

 

1.         The transmission provider must run a voluntary, bid-based, security constrained day-ahead market.  "Voluntary" means that market participants do not have to buy or sell in the day-ahead market, as explained further below.  "Bid-based" means that participants in the energy market may provide prices over the range of quantities that they offer into the market or seek to buy from the market.  "Security constrained" means that the market administrator, through the energy auction process, accounts for all transmission system constraints, such as contingency limits, needed for reliable system operations.

 

2.         The day-ahead market should be transparent (i.e., the rules of operation should be clear and understandable, and the software implementing the rules should produce predictable results) so that market participants can offer informed bids and trust market operations.

 

3.         Since the day-ahead market is voluntary for market participants, market participants should be able to schedule bilateral transactions and/or self supply rather than bid into the day-ahead market.  Long-term contracts and other means of avoiding price volatility and ensuring generation capacity adequacy should be fully accommodated.

 

4.         Bidding parameters must allow customers the opportunity to reflect the value they place on purchasing in the energy market and allow suppliers the opportunity to reflect the costs and operational constraints of production in the energy market.

 

5.         Demand can best respond by participating in the day-ahead market.  Demand response options should be available so that end users can respond to price signals and reduce loads as they feel the price exceeds their individual willingness to pay for delivered electricity.

 

            Scheduling and Bidding Rules

 

6.         The demand side must be able to participate in the energy market.  The demand side can participate as buyers or sellers (e.g., offering to sell operating reserves).  As a buyer, an entity must be able to submit bids that indicate it is willing to vary the quantities it purchases based on the prices that it may be charged.

 

7.         Sellers (including demand side) must have the option of submitting multi-part bids, e.g., submitting separate but related bids for start-up costs, no load costs and energy.  Multi-part bidding allows generators to provide more detailed cost information that can improve the ability of the grid operator to dispatch generators with the lower total cost.  Buyers must also be able to submit multi-part bids that indicate the time and price constraints under which they are willing to purchase energy in the day-ahead market.

 

8.         Individual market participants must not be required to submit balanced schedules (where demand and supply are equal), although they may submit balanced schedules if they choose to.  The transmission provider will match separate unbalanced supply and demand bids to ensure that aggregate generation and load are matched and the aggregate schedule is balanced.  However, as discussed in principle 11 in the Real-Time Energy Markets section below, special rules may be necessary to address deviations in real time from day-ahead schedules that threaten transmission reliability.

                                                                                   

9.         Bids need not be tied to a physical resource.  However, for reliability purposes, bids must indicate whether or not they are tied to a physical resource.

 

10.       Limits may be necessary on bidding flexibility to mitigate market power.  For example, suppliers may be required to submit a start-up bid which would remain in place for a period of several months (rather than re-bid every day).  As more demand response becomes available in a regional market, limits on supplier bidding flexibility can be relaxed.

 

11.       Additional scheduling options may need to be developed to address the special conditions facing energy-limited resources (e.g., hydroelectric power and environmentally constrained thermal power).  However, these additional options should be available to all generators and should not be restricted to energy-limited resources, unless such restrictions are necessary to mitigate market power that has arisen. 

 

12.       Intermittent resources should be able to participate in the day-ahead market on the same basis as other resources.

                                                                                                           

            Price Determination and Settlement

 

13.       Nodal pricing must be used for both buyers and sellers in the day-ahead market.  Nodal pricing establishes separate prices at each node (in contrast to zonal pricing, which establishes the same price at all nodes within a zone regardless of congestion).  Energy prices incorporate the total value of generation, transmission congestion, and losses at each node on the system. 

 

14.       An auction must be run to establish a single market-clearing price at each node.  These prices at a minimum are hourly prices.  (Smaller time intervals are acceptable.)  Buyers and sellers transact at the clearing price.  However, if a  seller’s total bid costs (including startup, no-load costs, minimum run time, and other physical characteristics as well as energy running costs) over the entire day are not fully covered by its revenues from selling at the hourly clearing prices, it will receive an uplift payment for the net revenue shortfall for the day.  Hourly energy prices are based only on energy bids; start-up cost bids are not used in calculating hourly energy prices.  Thus, a generator may have legitimate start-up costs that are not fully covered by selling at the hourly energy price over the day; paying uplift may be necessary to ensure that generators selected in the auction will receive revenues that fully cover their bid-costs.[4]

 

15.       The results of the day-ahead market must be financially binding on buyers and sellers.  In other words, sellers must be paid the day-ahead price for energy scheduled to be sold in the day-ahead market, and buyers must pay the day-ahead price for energy scheduled to be bought in the day-ahead market.  In addition, to the extent sellers and buyers fail to produce or take energy according to their respective schedules, such imbalances must be settled at the real-time energy price.  Thus, a seller must pay the real-time price for any scheduled energy that it promises but fails to produce in real time.  Similarly, a buyer must be paid the real-time price for any scheduled energy that it promises but fails to take in real time.

 

16.       Upon request of the market participants, the transmission provider should establish trading hub(s), i.e., a hub price that is the weighted average of prices at selected nodes on the system.

 

17.       The transmission provider must post prices and other market information and settle the markets on a timely basis to provide market participants with reliable information regarding their market transactions.

                                               

Real-Time Energy Markets

 

            General Features

 

1.         The transmission provider must run a bid-based, security constrained real-time market.  These characteristics are explained above.

 

2.         The real-time market should be transparent so that market participants can offer informed bids and trust market operations.

 

3.         Market participants must be able to revise their schedules for bilateral transactions, including long-term contracts, and self-supply after the close of the day-ahead market.  However, all imbalances will be settled through the real-time market, i.e., to the extent a buyer or seller is short, it must purchase power at the applicable real-time price for the shortfall; to the extent the buyer or seller is long, it will be paid the applicable real-time price for the excess amount. 

 

            Scheduling and Bidding Rules

 

4.         Bids to sell in the real-time market must be one-part energy bids, i.e., bids for energy only.  (Separate bids should not be submitted for start-up and no load costs since the energy suppliers should already be on-line and ready to respond to dispatch instructions.  Real-time market bids may, however, include information regarding minimum run times).

 

5.         The demand side must be able to participate in the real-time market.

 

6.         Limits may be necessary on bidding flexibility to address market power issues. 

 

7.         Additional scheduling options may need to be developed to address the special conditions facing energy-limited resources (e.g., hydroelectric power and environmentally constrained thermal power).  However, these additional options should be available to all generators and should not be restricted to energy-limited resources, unless such restrictions are necessary to mitigate market power that has arisen.

 

8.         Intermittent resources should be able to participate in the real-time market on the same basis as other resources.

 

            Price Determination and Settlement

 

9.         Nodal pricing must be used for both buyers and sellers in the real-time market.  Locational energy prices should reflect transmission congestion and losses.

 

10.       Real-time prices will be established for each node through market clearing price auctions.  These prices are generally for five-minute periods within the hour. Buyers and sellers transact at the clearing price.

 

11.       All deviations and imbalances from the day-ahead market will be settled through the real-time market at the real-time price.  In addition, real-time imbalances (i.e., individual market participants' uninstructed deviations in real time from their day-ahead schedules or dispatch instructions) that threaten transmission system reliability may require special rules, including penalties.

 

12.       The transmission provider must post prices and other market information and settle the markets on a timely basis to provide market participants with reliable information regarding their market transactions.

 

Regulation and Operating Reserves to Meet Reliability Requirements

 

            Transmission providers must ensure that ancillary services, including regulation and operating reserves, are provided.  Regulation provides moment-by-moment balancing of generation and load on the system.  Operating reserves ensure reliable service by covering contingencies such as the failure of a supply source or a transmission line.  Order No. 888 envisioned that these would be provided as a tariff service subject to a cost-based