skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: Sensitivity analysis of convergence bids in nodal electricity markets
Recent reports from Independent System Operators (ISOs) have raised some concerns about the impact of convergence bids (CBs) on nodal electricity markets. In particular, in some cases, there are concerns about cases where CBs are profitable for some market participants without increasing market efficiency significantly or even decreasing market efficiency. The latter occurs when CBs create price divergence instead of price convergence across the day-ahead and real-time markets. Accordingly, in this paper, we investigate the sensitivity of nodal electricity market price to CBs and seek to build an analytical foundation to explain under what conditions placing a CB at a bus in a nodal electricity market can create price divergence at that bus. Illustrative test cases are discussed to provide intuitions and engineering implications of the results on sensitivity analysis.  more » « less
Award ID(s):
1711944
PAR ID:
10073085
Author(s) / Creator(s):
;
Date Published:
Journal Name:
IEEE PES North American Power System Symposium
Page Range / eLocation ID:
1 to 6
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. null (Ed.)
    Convergence bidding, has been adopted in recent years by most Independent System Operators (ISOs) in the United States as a relatively new market mechanism to enhance market efficiency. Convergence bidding affects many aspects of the operation of the electricity markets and there is currently a gap in the literature on understanding how the market participants strategically select their convergence bids in practice. To address this open Problem, in this paper, we study three years of real-world market data from the California ISO energy market. First, we provide a data - driven overview of all submitted convergence bids (CBs) and analyze the performance of each individual convergence bidder based on the number of their submitted CBs, the number of locations that they placed the CBs, the percentage of submitted supply or demand and CBs, the amount of cleared CBs, and their gained profit or loss. Next, we scrutinize the bidding strategies of the 13 largest market players that account for 75 % of all CBs in. the California ISO market. We identify quantitative features to characterize and distinguish their different convergence bidding strategies. This analysis results in revealing three different classes of CB strategies that are used in practice. We identify the differences between. these strategic bidding classes and compare their advantages and disadvantages. We also explain how some of the most active market participants are using bidding strategies that do not any of the strategic bidding methods that currently exist in the literature. 
    more » « less
  2. Tâtonnement is a simple, intuitive market process where prices are iteratively adjusted based on the difference between demand and supply. Many variants under different market assumptions have been studied and shown to converge to a market equilibrium, in some cases at a fast rate. However, the classical case of linear Fisher markets have long eluded the analyses, and it remains unclear whether tâtonnement converges in this case. We show that, for a sufficiently small stepsize, the prices given by the tâtonnement process are guaranteed to converge to equilibrium prices, up to a small approximation radius that depends on the stepsize. To achieve this, we consider the dual Eisenberg-Gale convex program in the price space, view tâtonnement as subgradient descent on this convex program, and utilize novel last-iterate convergence results for subgradient descent under error bound conditions. In doing so, we show that the convex program satisfies a particular error bound condition, the quadratic growth condition, and that the price sequence generated by tâtonnement is bounded above and away from zero. We also show that a similar convergence result holds for tâtonnement in quasi-linear Fisher markets. Numerical experiments are conducted to demonstrate that the theoretical linear convergence aligns with empirical observations. 
    more » « less
  3. Electricity systems in many parts of the world are becoming more dependent upon natural gas as an electricity-generation fuel. As such, electricity and natural-gas markets are becoming more interconnected. Contemporaneously, some electricity and natural-gas markets are integrating vertically, through the merger of electricity and natural-gas suppliers. The market-efficiency impacts of such vertical integration are unclear. On one hand, vertical integration could exacerbate market power, whereas on another it could mitigate double marginalization. To study this question, this paper develops a Nash–Cournot model of the two interconnected markets. The model is converted into a linear complementarity problem, which allows deriving Nash equilibria readily. Some theoretical results are derived for the case of a merger involving symmetric firms. In addition, the model is applied to a stylized example with a range of parameter values. We find that integration is social-welfare enhancing—which implies that mitigating double marginalization outweighs the exercise of market power. In most cases, the effects of merger can give rise to a prisoner’s-dilemma-type outcome. Merger is beneficial to the merging firms. However, profits of non-merging firms and total supplier profits decrease following a merger. Overall, our results suggest that vertical integration in energy markets may be socially beneficial. JEL Classification:C61, C72, D43, L1, L94, L95, Q4 
    more » « less
  4. If a trader could predict price changes in the stock market better than other traders, she would make a fortune. Similarly in the electricity market, a trader that could predict changes in the electricity load, and thus electricity prices, would be able to make large profits. Predicting price changes in the electricity market better than other market participants is hard, but in this paper, we show that attackers can manipulate the electricity prices in small but predictable ways, giving them a competitive advantage in the market. Our attack is possible when the adversary controls a botnet of high wattage devices such as air conditioning units, which are able to abruptly change the total demand of the power grid. Such attacks are called Manipulation of Demand via IoT (MaDIoT) attacks. In this paper, we present a new variant of MaDIoT and name it Manipulation of Market via IoT (MaMIoT). MaMIoT is the first energy market manipulation cyberattack that leverages high wattage IoT botnets to slightly change the total demand of the power grid with the aim of affecting the electricity prices in the favor of specific market players. Using real-world data obtained from two major energy markets, we show that MaMIoT can significantly increase the profit of particular market players or financially damage a group of players depending on the motivation of the attacker. 
    more » « less
  5. This paper discusses a market-based pool strategy for a microgrid (MG) to optimally trade electric power in the distribution electricity market (DEM). The increasing penetration levels of distributed energy resources (DERs) and MGs in distribution system (DS) stress distribution system operator (DSO) and require higher levels of coordinated control strategies. The distribution system operator has limited visibility and control over such distributed resources. To reduce the complexity of the system and improve the efficiency of the electricity market operation, we propose a decentralized pool strategy for an MG to integrate with a distribution system through a market mechanism. A market-based interactions procedure between MGs and DS is developed for MGs as price-makers to find an optimal bidding/offering strategy efficiently. To achieve a market equilibrium among all entities, we initially cast this problem as a bi-level programming problem, in which the upper level is an MG optimal scheduling problem and the lower level presents a DEM clearing mechanism. The proposed bi-level model is converted to a single mix-integer model which is easier to solve. Uncertainties associated with MG's rivals' offers and demands' bids are considered in this problem. The solution results from a modified IEEE 33-Bus distribution system are presented and discussed. Finally, some conclusions are drawn and examined. 
    more » « less