Integrated Transmission and Distribution (ITD) Systems: Project Homepage


Last Updated: 24 October 2020

Site maintained by:
Leigh Tesfatsion
Research Professor & Professor Emerita of Economics
Courtesy Research Professor of Electrical & Computer Engineering
260 Heady Hall
Iowa State University
Ames, Iowa 50011-1054
http://www2.econ.iastate.edu/tesfatsi
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Integrated T&D System

Table of Contents:

Regular Project Meeting Time/Place:

Regular ISU Meetings (Summer/Fall 2020): Weekly Zoom/WebEx meetings

ITD Project Description

The growing penetration of diverse variable energy resources (wind, solar, ...) in modern electric power systems at both the transmission and distribution (T/D) levels has increased the uncertainty of net load as well as the frequency of strong ramp events, complicating the maintenance of net load balance. In response to these trends, power system researchers and operators are proposing new market-based initiatives intended to facilitate the efficient and reliable provision of power and ancillary services from a wide array of T/D resources. The implementation of such initiatives implies tighter feedback connections between T/D system levels.

Three major premises of this project are therefore as follows: First, to ensure efficient and reliable operation of future power systems, researchers need to consider with care the integrated operation of T/D systems over time. Second, researchers need to develop scalable market-based approaches that permit the efficient flexible procurement of power and ancillary services from distributed T/D resources as the number of these resources continues to increase. Third, to evaluate the technical and financial feasibility of these approaches in advance of implementation, researchers need computational frameworks that permit integrated T/D systems to be modeled and studied as coherent dynamic systems with grid sizes ranging from small to realistically large, and with an appropriate degree of empirical verisimilitude.

A Grid-Edge Resource (GER) is defined to be any power resource with a direct point of connection to a distribution grid. Examples include households, businesses, and devices directly connected to the distribution grid. A GER Aggregator is any entity that manages power usage, power supply, and/or ancillary service provision for a collection of GERs.

A primary goal of this project is to investigate the ability of GER aggregators, making use of innovative types of swing contracts, to ensure the availability and flexible real-time usage of reserve (dispatchable power paths) extracted from GERS in support of integrated transmission and distribution (ITD) system operations. This investigation will be carried out in part by means of an empirically based computational modeling of an ITD system.

Based on work to date, our conjecture is that permitting swing contracting by GER aggregators and other participants in ISO/RTO-managed wholesale power markets will facilitate the robust-control management of risks and uncertainties for ITD systems. This robust control approach does not require detailed scenario and probability specifications or reliance on overly conservative worst-case designs.

ITD Project Participants (Alphabetical Order)

Swathi Battula (GRA, DOE/PNNL Projects, ISU ECpE PhD Program), Jan 2017-present.

Subhonmesh Bose (Assistant Professor, U of Illinois at Urbana-Champaign), July 2019-present.

Rui Cheng (GRA, PSERC Project, ISU ECpE PhD Program), August 2019-present.

Shanshan Ma (GRA, DOE Project, ISU ECpE PhD Program), January 2017-present.

Mariola Ndrio (GRA, PSERC Project, U of Illinois at Urbana-Champaign), July 2019-present.

Hieu Trung Nguyen (Post-Doctoral Research Associate, DOE Project), May 2017-August 2018.

Rohit Reddy Takkala (GRA, PNNL Project, ISU ECpE MS) Sept 2017-June 2018.

Leigh Tesfatsion (Research Professor, and Professor Emerita of Econ, Math, and ECpE, 375 Heady, ISU)

Jianhui Wang (Professor of Engineering, Southern Methodist University)

Zhaoyu Wang (Harpole Pentair Endowed Assistant Professor of ECpE, 1113 Coover Hall, ISU)

Anna Winnicki (GRA, PSERC Project, U of Illinois at Urbana-Champaign), July 2019-present.

Contract & Grant Support

Colciencias Programa 852
Sponsor: Colciencias, Modalidad Programas
Title: "Valuing Variability in the Colombian Electricity Market"
External Expert Advisor: Leigh Tesfatsion
Start Date of Award: March 2020
End Date of Award: February 2023

PSERC Project M-40
Sponsor: Power Systems Engineering Research Center (PSERC)
Title: "Market and Control Mechanisms Enabling Flexible Service Provision by Grid-Edge Resources within End-to-End Power Systems"
PI: Leigh Tesfatsion
Co-PI: Zhaoyu Wang
Co-PI: Subhonmesh Bose
Start Date of Award: July 2019
End-Date of Award: June 2021

DOE Project
Sponsor: Office of Electricity (OE), U.S. Department of Energy (DOE)
Title: "Flexible Service Contracting for Risk Management within Integrated Transmission and Distribution Systems"
PI: Zhaoyu Wang
Co-PI: Leigh Tesfatsion
Co-PI: Jianhui Wang
Start Date of Award: January 1, 2017
End-Date of Award: September 30, 2020

PNNL Project
Sponsor: Pacific Northwest National Laboratory (PNNL)
Title: "Regional Scale Transactive System Study in the ERCOT Region of Texas"
PI: Leigh Tesfatsion
Co-PI: Zhaoyu Wang
Collaborators: PNNL Team
Start Date of Contract: March 19, 2018
End Date of Contract: July 31, 2019

PNNL Project
Sponsor: Pacific Northwest National Laboratory (PNNL)
Title: "Development of an Integrated Transmission and Distribution Test System to Evaluate Transactive Energy Systems"
PI: Leigh Tesfatsion
Co-PI: Zhaoyu Wang
Collaborators: PNNL Team
Start Date of Contract: April 1, 2017
End Date of Contract: July 31, 2019

EPRC Project
Sponsor: Electric Power Reseach Center (EPRC)
Title: "Integrated Distribution and Transmission Effects of Demand-Response Initiatives"
PI: Leigh Tesfatsion
Start Date of Award: August 1, 2015
End Date of Award: July 31, 2016

Project-Related Publications (Chronological Order)

Book:

Leigh Tesfatsion (2020), A New Swing-Contract Design for Wholesale Power Markets (Table of Contents/Intro/Refs), (Slide-Set Overview), 21 Chapters, 272pp., Wiley/IEEE Press, December. ISBN-13: 978-1119670124; ISBN-10: 1119670128

Journal Articles and Book Chapters:

Swathi Battula, Leigh Tesfatsion, and Zhaoyu Wang (2020), "A Customer-Centric Approach to Bid-Based Transactive Energy System Design" (WP Preprint,pdf,1.7MB), IEEE Transactions on Smart Grid 11(6), 4996-5008. DOI: 10.1109/TSG.2020.3008611

Swathi Battula, Leigh Tesfatsion, and Thomas E. McDermott (2020), "An ERCOT Test System for Market Design Studies" (WP Preprint,3.4MB), Applied Energy, Vol. 275, October. DOI: 10.1016/j.apenergy.2020.115182

Shanshan Ma, Zhaoyu Wang, and Leigh Tesfatsion (2019), "Swing Contracts with Dynamic Reserves for Flexible Service Management" (IEEE Preprint,1.4MB,pdf), IEEE Transactions on Power Systems, Vol. 34, Issue 5, 4024-4037. DOI: 10.1109/TPWRS.2018.2831924

Hieu T. Nguyen, Swathi Battula, Rohit Reddy Takkala, Zhaoyu Wang, and Leigh Tesfatsion (2019), "An Integrated Transmission and Distribution Test System for Evaluation of Transactive Energy Designs" (AE Preprint,pdf,1.9MB), Applied Energy, Volume 240, 666-679.

Khaled Alshehri, Mariola Ndrio, Subhonmesh Bose, and Tamer Basar (2019), "The Impact of Aggregating Distributed Energy Resources on Electricity Market Efficiency" (IEEE Xplore), Proceedings, 53rd Annual Conference on Information Sciences and Systems (CISS), Baltimore, Maryland, USA, April 18.

Auswin G. Thomas and Leigh Tesfatsion (2018), "Braided Cobwebs: Cautionary Tales for Dynamic Pricing in Retail Electric Power Markets" (IEEE Preprint,546KB,pdf), IEEE Transactions on Power Systems, Volume 33, Issue 6, pp. 6870-6882. DOI: 10.1109/TPWRS.2018.2832471

Leigh Tesfatsion (2018), "Electric Power Markets in Transition: Agent-Based Modeling Tools for Transactive Energy Support" (ScienceDirect), Chapter 13 (pp. 715-766) in Cars Hommes and Blake LeBaron (Eds.), Handbook of Computational Economics 4: Heterogeneous Agent Models, Handbooks in Economics Series, North Holland (Elsevier), Amsterdam, the Netherlands.

Wanning Li and Leigh Tesfatsion (2018), "A Swing-Contract Market Design for Flexible Service Provision in Electric Power Systems" [(WP,pdf,463KB), (Talk Slides,pdf,694KB)], Chapter 5 (pp. 105-127) in: Sean Meyn, Tariq Samad, Ian Hiskens, and Jakob Stoustrup (Eds.), Energy Markets and Responsive Grids: Modelling, Control, and Optimization, The IMA Volumes in Mathematics and its Applications Series, Springer.

Tianguang Lu, Zhaoyu Wang, Jianhui Wang, Qian Ai, and Chong Wang (2018), "A Data-Driven Stackelberg Market Strategy for Demand Response-Enabled Distribution Systems", IEEE Transactions on Smart Grid (IEEE Xplore), Vol. 10, Issue 3, May 2019, pp. 2345-2357.

Leigh Tesfatsion (2017), "Modeling Economic Systems as Locally-Constructive Sequential Games" [ (Preprint,pdf,654KB), (Slides,pdf,1MB)], Journal of Economic Methodology, Volume 24, Issue 4, 384-409.

Dheepak Krishnamurthy, Wanning Li, and Leigh Tesfatsion (2016), "An 8-Zone Test System based on ISO New England Data: Development and Application" (pdf, 642KB), IEEE Transactions on Power Systems, Vol. 31, No. 1, January, 234-246.

Zhaoyu Wang and Yanyi He (2016), "Two-stage Optimal Demand Response with Battery Energy Storage Systems", IET Generation, Transmission and Distribution, vol. 10, no. 5, April, 1286-1293.

Deung-Yong Heo and Leigh Tesfatsion (2015), "Facilitating Appropriate Compensation of Electric Energy and Reserve through Standardized Contracts with Swing" (Preprint,pdf,902KB), Journal of Energy Markets, Vol. 8, No. 4, December, 93-121.

Zhaoyu Wang, Bokan Chen, Jianhui Wang, and Miroslav Begovic (2015) "Stochastic DG Placement for Conservation Voltage Reduction based on Multiple Replications Procedure", IEEE Transactions on Power Delivery, Vol. 30, No. 3, June, 1039-1047.

Zhaoyu Wang, Bokan Chen, Jianhui Wang, Miroslav Begovic, and Chen Chen (2015), "Coordinated Energy Management of Networked Microgrids in Distribution Systems", IEEE Transactions on Smart Grid, Vol. 6, No. 1, January, 45-53.

Project-Related Reports (Chronological Order)

Leigh Tesfatsion and Swathi Battula (2020), "Analytical SCUC/SCED Optimization Formulation for AMES V5.0" (pdf,1.7MB), Working Paper No. 20014, Economics Working Paper Series, Iowa State University, Ames, IA.

Leigh Tesfatsion and Swathi Battula (2020), "Notes on the GridLAB-D Household Equivalent Thermal Parameter Model" (WP,pdf,819KB), Working Paper No. 19001, Economics Working Paper Series, Iowa State University, Ames, IA. Latest Revision: July 2020.

Swathi Battula, Leigh Tesfatsion, and Zhaoyu Wang (2019), "A Transactive Energy Approach to Distribution System Design: Household Formulation" (pdf,1.7MB), Working Paper No. 19010, Economics Working Paper Series, Iowa State University, Ames, IA. (Shortened revised version published in the IEEE Transactions on Smart Grid, 2020.)

Hieu Trung Nguyen, Swathi Battula, Rohit Reddy Takkala, Zhaouyu Wang, and Leigh Tesfatsion (2018). "Transactive Energy Design for Integrated Transmission and Distribution Systems" (WP,pdf,1.4MB), Working Paper No. 18004, Economics Working Paper Series, Iowa State University, Ames, IA. (Shortened revised version published in Applied Energy, 2019.)

Wanning Li and Leigh Tesfatsion (2017), "An 8-Zone ISO-NE Test System with Physically-Based Wind Power" (WP,pdf,870KB) Working Paper No. 17-2017, Economics Working Paper Series, Iowa State University, Ames, Iowa.

Leigh S. Tesfatsion, César A. Silva-Monroy, Verne W. Loose, James F. Ellison, Ryan T. Elliott, Raymond H. Byrne, and Ross T. Guttromson (2013), "New Wholesale Power Market Design Using Linked Forward Markets: A Study for the DOE Energy Storage Systems Program" (pdf,1.4MB), Sandia National Laboratories Report, SAND2013-2789, Unlimited Release, April.

Project-Related Presentations (Chronological Order)

Leigh Tesfatsion, "A New Swing-Contract Design for Wholesale Power Markets" (Talk-Slides,1MB), WebEx presentation, sponsored by the Electric Power Research Institute (EPRI), September 18, 2020.

Rui Cheng, Leigh Tesfatsion, and Zhaoyu Wang, “Multi-Period Consensus-Based Trans-active Control in an Unbalanced Distribution Network", Transactive Energy Systems Theory Workshop (WebEx), Pacific Northwest National Laboratory, September 17, 2020.

Leigh Tesfatsion, "Flexible Service Contracting for Risk Management within Integrated Transmission and Distribution Systems", DOE/OE Transmission Reliability, Reliability & Market Program Peer Review Meeting, Sphinx on K, Washington, D.C., June 11, 2019.

Leigh Tesfatsion, "Market and Control Mechanisms Enabling Flexible Service Provision by Grid-Edge Resources within End-to-End Power Systems", Power Systems Engineering Research Center (PSERC) IAB Meeting, UC Berkeley, Dec 5-7, 2018.

Leigh Tesfatsion, Keynote Address: "Agent-Based Modeling Support for Institutional Design", CSS 2018, The Computational Social Science Society of the Americas, Santa Fe, New Mexico, Oct 25-28, 2018.

Shanshan Ma, Zhaoyu Wang, and Leigh Tesfatsion, "Swing Contracts with Dynamic Reserves for Flexible Service Management", IEEE Power & Energy Society General Meeting (GM 2018), Portland, OR, Aug 5-9, 2018.

Leigh Tesfatsion, "Theory Development Through Agent-Based Modeling" (webinar), Symposium I: State of the Art & Epistemological Perspectives on Theory Development Through Agent-Based Modeling, Hannover, Germany, July 4-6, 2018.

Leigh Tesfatsion, "Swing Contract Transactive Energy System Designs for End-to-End Power Systems", Hybrid Economic-Control Theory Workshop, MIT, Cambridge, MA, June 11, 2018.

Zhaoyu Wang, "Agent-Based Modeling for Integrated Transmission and Distribution Test Systems", 2018 IEEE PES T&D Conference and Exposition, Denver, CO, April 16-19, 2018.

Leigh Tesfatsion, "Electric Power Markets in Transition: Agent-Based Modeling Tools for Transactive Energy Support" Invited Talk (via Skype), Invenia Labs, Cambridge, UK, March 22, 2018.

Zhaoyu Wang, "Integrated Transmission and Distribution Test Beds", Invited Talk, University of Bath, Bath, UK, January 16, 2018.

Leigh Tesfatsion, "Modeling Coupled Natural and Human Systems as Locally-Constructive Sequential Games", Invited Talk (Skype), ABM Seminar, University of Minnesota, Mpls., November 8, 2017.

Zhaoyu Wang, "Integrated Wholesale and Retail Power System Testbeds", Invited Talk, Springfield City Utilities, Springfield, MO, October 19, 2017.

ITD Project Team (via Skype), "Transactive Energy System Designs for End-to-End Power Systems with Massively Distributed Energy Resources", PNNL TESP Workshop, Richland, WA, October 16, 2017.

Leigh Tesfatsion, "Agent-Based Modeling Tools for Electric Power Market Design: Implications for Macro/Financial Policy", Heterogeneous Agents and Agent-Based Modeling: The Intersection of Policy and ResearchM, Joint Conference of the Office of Financial Research (U.S. Treasury), Brandeis University, and the Bank of England, held at U.S. Treasury, Washington, D.C., September 21-22, 2017.

Leigh Tesfatsion, "Electric Power Markets in Transition: Agent-Based Modeling Tools for Transactive Energy Support" (via Skype), Amsterdam Business School, Amsterdam, the Netherlands, June 1, 2017.

Zhaoyu Wang, "DOE Project Research Summary", Electric Power Research Center IAB Meeting, Iowa State University, May 14, 2017.

Leigh Tesfatsion, "Modeling Economic Systems as Locally Constructive Sequential Games", Social Behavioral Modeling and Simulation Workshop, Sponsored by the Defense Advanced Research Project Agency (DARPA), RAND Corporation, Santa Monica, CA, April 3-4, 2017.

Leigh Tesfatsion, "Economic Systems as Constructively Rational Games: Oh, the Places We Could Go!", International Congress on Agent Computing, George Mason University, Nov 29-30, 2016.

Leigh Tesfatsion, Keynote Address, "Economic Systems as Constructively Rational Games: Oh, the Places We Could Go!", Economics in the Era of Natural Computation and Big Data, Duke Forest Conference, Durham, North Carolina, Nov. 11-13, 2016.

Auswin G. Thomas and Leigh Tesfatsion, "Using Test Systems to Explore Integrated Transmission and Distribution System Operations with SmartGrid Functionality: A Demand- Response Illustration", IEEE PES General Meeting, Boston, MA, July 17-21, 2016.

Wanning Li and Leigh Tesfatsion, "Market Provision of Flexible Energy/Reserve Contracts: Optimization Formulation", Proceedings, IEEE PES General Meeting, Boston, MA, July 17-25, 2016.

Wanning Li and Leigh Tesfatsion, "Market Provision of Flexible Energy/Reserve Contracts", FERC Technical Conference, Washington, D.C., June 27-29, 2016.

Leigh Tesfatsion, "Facilitating Flexible Service Provision in Electric Power Markets via Swing Contracting", Control at Large Scales: Energy Markets and Responsive Grids, Institute for Mathematics and its Applications (IMA), Mpls, May 9-13, 2016.

Steve Widergren, Koen Kok, and Leigh Tesfatsion, "Transactive Energy Systems", Webinar, IEEE SmartGrid, 10 March 2016.

Koen Kok, Steve Widergren, and Leigh Tesfatsion, "Intelligent Systems Support for Transactive Energy Systems: The Fundamentals", Half-Day Tutorial, IEEE Power and Energy Society General Meeting, Denver, CO, July 26-30, 2015.

Leigh Tesfatsion and Deung-Yong Heo, "Facilitating Appropriate Compensation of Electric Energy and Reserve Through Standardized Contracts with Swing", Panel Session: Effects of Contract Design on Electricity Market Performance with Increased Penetration of Distributed Energy Resources and Variable Generation, IEEE Power and Energy Society General Meeting, Denver, CO, July 26-30, 2015.

Auswin G. Thomas and Leigh Tesfatsion, "Integrated Transmission and Distribution Effects of Demand-Side Participation", Panel Session: Wholesale and Retail Market Interaction Requirements for Effective Demand-Side Participation, IEEE Power and Energy Society Meeting, Denver, CO, July 26-30, 2015.

Software

ITD Project/Household Formulation (open source, Python): Released 10/2020.

ITD Project/Household Formulation (GitHub Repository) provides Python code and data in support of Battula, Tesfatsion, and Wang (2020), "A Customer-Centric Approach to Bid-Based Transactive Energy System Design", IEEE Transactions on Smart Grid 11(6), 4996-5008.

AMES V5.0 (open source, Java/Python): Released 8/7/2020

AMES V5.0 (GitHub Repository) is an open source software platform capturing salient features of U.S. RTO/ISO-managed wholesale power markets operating over high-voltage transmission grids, with congestion handled by locational marginal pricing. AMES V5.0 was developed by Swathi Battula and Leigh Tesfatsion at Iowa State University, with support from researchers at the Pacific Northwest National Laboratory (Tom McDermott, Mitch Pelton, Qiuhua Huang, and Sarmad Hanif). AMES V5.0 consolidates features from previous AMES versions and continues the main developments in these previous versions.

AMES V5.0 supports the submission of supply offers and demand bids (in both fixed and price-sensitive form) into daily DAM SCUC/SCED and RTM SCED optimizations formulated as Mixed Integer Linear Programming (MILP) problems with a comprehensive set of system constraints. It permits continual updating of initial state conditions to permit market operations to run over successive days. The package includes an 8-bus test case based on data, operations, and market timing for the Electric Reliability Council of Texas (ERCOT) energy region.

In addition, AMES V5.0 is integrated with a high-level simulation framework that permits it to function as a software component within larger systems, such as multiple seamed energy regions or integrated transmission and distribution systems.

ERCOT Test System (open source, Java/Python, implemented in part by AMES V5.0): Released 8/7/2020

The ERCOT Test System (GitHub Repository) was developed by Swathi Battula and Leigh Tesfatsion at Iowa State University and Thomas E. McDermott at the Pacific Northwest National Laboratory.

In default mode, the ERCOT Test System models ISO-managed day-ahead and real-time market operations in the Electric Reliability Council of Texas (ERCOT) energy region. Modeled market participants include dispatchable generators, load-serving entities, and non-dispatchable generation such as unfirmed wind and solar power. Users can configure a broad variety of parameters to study basic ERCOT market and grid features under alternative system conditions.

Users can also easily extend the test system's Java/Python software classes to study modified or newly envisioned market and grid features. In addition, the test system is integrated with a high-level simulation framework that permits it to function as a software component within larger systems, such as multiple seamed energy regions or integrated transmission and distribution systems.

A detailed description of the ERCOT Test System, together with illustrative 8-bus and 200-bus ERCOT test cases, can be found in the following paper:

Eight Zone ISO-NE Test System (open source, Java/Python, implemented in part by AMES V4.0): Released 11/30/2015

The 8-Zone ISO-NE Test System, based on ISO New England data and characteristics, was developed by Dheepak Krishnamurthy, Wanning Li, and Leigh Tesfatsion at Iowa State University. Code for the test system and illustrative test cases can be accessed at the 8-Zone ISO-NE Test System Repository.

A detailed description of the 8-Zone ISO-NE Test System, together with illustrative applications, can be found in the following two papers:

GridLAB-D: Electric Energy Distribution Platform (open source, C++/C)

GridLAB-D is a distribution system simulation platform developed by researchers at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington. PNNL maintains a GridLAB-D Site at SourceForge. The following paper provides a general introduction to GridLAB-D:

Online Background Materials

Articles and Reports:

NERC, Distributed Energy Resources: Connection Modeling and Reliability Considerations (pdf,1.8MB), North American Electric Reliability (NERC) Corporation Report, Atlanta, Georgia, February 2017.

NAS, Analytic Research Foundations for the Next-Generation Electric Grid (pdf,9.3MB), National Academies of Science, The National Academies Press, Washington, D.C., 2016.

Philipp Ringler, Dogan Keles, Wolf Fichtner, "Agent-Based Modelling and Simulation of Smart Electricity Grids and Markets - a Literature Review" (DOI Link), Renewable and Sustainable Energy Reviews 57 (2016),205-2015.

Maria Lorena Tuballa and Michael Lochinvar Abundo, "A Review of the Development of Smart Grid Technologies" (DOI Link), Renewable and Sustainable Energy Reviews 59 (2016), 710-723.

Websites:

General Resources on Electricity Restructuring

Agent-Based Computational Electricity Market Research

EE/Econ 458: Economic Systems for Electric Power Planning
Note: This power economics course has been designed for long-distance access. All lecture notes and assigned readings are posted on-line.

Open-Source Software for Electricity Market Research, Teaching, and Training

MISO: Midcontinent ISO Homepage

ISO-NE: ISO New England Homepage

PJM Homepage

NY-ISO: New York ISO Homepage

CAISO: California ISO Homepage

ERCOT: Electric Reliability Council of Texas Homepage

SPP: Southwest Power Pool Homepage

The Midcontinent Independent System Operator (MISO) maintains a MISO Dynamic LMP Contour Map for day-ahead and real-time LMPs (refreshed every five minutes), accompanied by information in chart and tabular form.

The New England Independent System Operator (ISO-NE) maintains a ISO-NE Dynamic LMP Contour Maps for day-ahead and real-time LMPs (refreshed every five minutes), accompanied by information in chart and tabular form.

The New York Independent System Operator (NYISO) maintains an NYISO Real-Time Dashboard that includes contour maps for day-ahead and real-time LMPs (refreshed every five minutes), accompanied by information in chart and tabular form.

The Southwest Power Pool (SPP) maintains an SPP Price Contour Map that includes contour maps for day-ahead and real-time LMPs (refreshed every five minutes), accompanied by information in chart and tabular form.