Supply Function Equilibria with Capacity Constraints and Pivotal Suppliers

The concept of a supply function equilibrium (SFE) has been widely used to model generators’ bidding behavior and market power issues in wholesale electricity markets. Observers of electricity markets have noted how generation capacity constraints may contribute to market power of generation firms. If a generation firm’s rivals are capacity constrained then the firm may be pivotal; that is, the firm could substantially raise the market price by unilaterally withholding output. However the SFE literature has not properly analyzed the impact of capacity constraints and pivotal firms on equilibrium predictions. We characterize the set of symmetric supply function equilibria for uniform price auctions when firms are capacity constrained and show that this set is increasing as capacity per firm rises. We provide conditions under which asymmetric equilibria exist and characterize these equilibria. In addition, we compare results for uniform price auctions to those for discriminatory auctions, and we compare our SFE predictions to equilibrium predictions of models in which bidders are constrained to bid on discrete units of output.supply function equilibrium, pivotal firm, wholesale electricity market

Virtual Power Plant Auctions

Since their advent in 2001, virtual power plant (VPP) auctions have been implemented widely. In this paper, we describe the simultaneous ascending-clock auction format that has been used for virtually all VPP auctions to date, elaborating on other design choices that most VPP auctions have had in common as well as discussing a few aspects that have varied significantly among VPP auctions. We then evaluate the various objectives of regulators in requiring VPP auctions, concluding that the auctions have been effective devices for facilitating new entry into electricity markets and for developing wholesale power markets.Auctions, electricity auctions, market design, virtual power plant auctions, clock auction, combinatorial auction

How Far Does Economic Theory Explain Competitive Nonlinear Pricing in Practice?

Liberalisation of the British electricity market, in which previously monopolised regional markets were exposed to large-scale entry, is used to test the propositions of several recent theoretical papers on oligopolistic nonlinear pricing. Consistent with those theories, each oligopolist offered a single two-part electricity tariff, and a lump sum discount to consumers who purchased both electricity and gas. However, inconsistent with those theories, firms’ two-part tariffs are heterogeneous in ways that cannot be attributed to cost. We establish a series of stylised facts about the nature of these asymmetries between firms and use them to confront established theory

A Consensus-ADMM Approach for Strategic Generation Investment in Electricity Markets

This paper addresses a multi-stage generation investment problem for a strategic (price-maker) power producer in electricity markets. This problem is exposed to different sources of uncertainty, including short-term operational (e.g., rivals' offering strategies) and long-term macro (e.g., demand growth) uncertainties. This problem is formulated as a stochastic bilevel optimization problem, which eventually recasts as a large-scale stochastic mixed-integer linear programming (MILP) problem with limited computational tractability. To cope with computational issues, we propose a consensus version of alternating direction method of multipliers (ADMM), which decomposes the original problem by both short- and long-term scenarios. Although the convergence of ADMM to the global solution cannot be generally guaranteed for MILP problems, we introduce two bounds on the optimal solution, allowing for the evaluation of the solution quality over iterations. Our numerical findings show that there is a trade-off between computational time and solution quality

Scenarios for the development of smart grids in the UK: synthesis report

‘Smart grid’ is a catch-all term for the smart options that could transform the ways society produces, delivers and consumes energy, and potentially the way we conceive of these services. Delivering energy more intelligently will be fundamental to decarbonising the UK electricity system at least possible cost, while maintaining security and reliability of supply. Smarter energy delivery is expected to allow the integration of more low carbon technologies and to be much more cost effective than traditional methods, as well as contributing to economic growth by opening up new business and innovation opportunities. Innovating new options for energy system management could lead to cost savings of up to £10bn, even if low carbon technologies do not emerge. This saving will be much higher if UK renewable energy targets are achieved. Building on extensive expert feedback and input, this report describes four smart grid scenarios which consider how the UK’s electricity system might develop to 2050. The scenarios outline how political decisions, as well as those made in regulation, finance, technology, consumer and social behaviour, market design or response, might affect the decisions of other actors and limit or allow the availability of future options. The project aims to explore the degree of uncertainty around the current direction of the electricity system and the complex interactions of a whole host of factors that may lead to any one of a wide range of outcomes. Our addition to this discussion will help decision makers to understand the implications of possible actions and better plan for the future, whilst recognising that it may take any one of a number of forms

Equilibrium Predictions in Wholesale Electricity Markets

We review supply function equilibrium models and their predictions on market outcomes in the wholesale electricity auctions. We discuss how observable market characteristics such as capacity constraints, number of power suppliers, load distribution and auction format affect the behavior of suppliers and performance of the market. We specifically focus on the possible market power exerted by pivotal suppliers and the comparison between discriminatory and uniform-price auctions. We also describe capacity investment behavior of electricity producers in the restructured industry.Electricity markets; Supply function equilibrium; Markov perfect equilibrium; electricity auctions; pivotal suppliers; capacity investment.

The co-evolutionary relationship between energy service companies and the UK energy system: Implications for a low-carbon transition

The Energy Service Company (ESCo) business model is designed to reward businesses by satisfying consumers' energy needs at less cost and with fewer carbon emissions via energy demand management and/or sustainable supply measures. In contrast, the revenue of the incumbent Energy Utility Company (EUCo) model is coupled with the sale of units of energy, which are predominantly sourced from fossil fuels. The latter is currently dominant in the UK. This paper addresses two questions. First, why has the ESCo model traditionally been confined to niche applications? Second, what role is the ESCo model likely to play in the transition to a low-carbon UK energy system? To answer these, the paper examines the core characteristics of the ESCo model, relative to the EUCo model. The paper then examines how ESCos have co-evolved with the various dimensions of the energy system (i.e. ecosystems, institutions, user practices, technologies and business models) to provide insight into how ESCos might help to shape the future UK energy system. We suggest that institutional and technological changes within the UK energy system could result in a more favourable selection environment for ESCos, consequently enabling the ESCo model to proliferate at the expense of the EUCo model. © 2013 Elsevier Ltd

Competition in Retail Electricity Supply

This paper presents an analysis and defence of competition in retail electricity supply. It includes some account of its development in the UK over the last dozen years, to the point where all retail price controls have now been removed. The development of this competition illustrates a number of the themes in Israel Kirzner’s writing - for example, the nature of competition as a process over time, the entrepreneurial and learning nature of this process, the role of marketing in alerting customers, the role of competition in establishing price and in discovering the services and suppliers that customers prefer, and the advantages of competition over regulation.competition, electricity, regulation, Austrian economics