What Is Power System Economics?

Power system economics is the application of economic theory, optimization methods, and market design principles to the production, dispatch, transmission, and pricing of electricity. It addresses how generation resources are scheduled to minimize costs, how transmission constraints shape the spatial distribution of prices, how competitive markets are structured to achieve efficient outcomes, and how investment decisions in generation and network infrastructure are made under regulatory and market uncertainty. The discipline bridges electrical engineering, operations research, and industrial organization economics, and its tools are embedded directly in the software systems that operate modern power grids.

Power systems present distinctive economic challenges: electricity cannot be economically stored at scale, demand fluctuates continuously, and supply and demand must be balanced in real time across a network whose physical laws constrain feasible power flows.

Electricity Markets and Deregulation

Prior to the restructuring of the electricity sector in the 1990s, vertically integrated utilities owned generation, transmission, and distribution assets and set prices under cost-of-service regulation. Deregulation separated these functions in many jurisdictions, opening generation to competitive entry while leaving transmission and distribution as regulated monopolies. The U.S. Energy Information Administration overview of electric system interconnections explains how the three main North American interconnections provide the physical backbone within which these markets operate. The U.S. Federal Energy Regulatory Commission (FERC) oversees wholesale market rules, while state commissions regulate retail tariffs. Research from the MIT Center for Energy and Environmental Policy Research has documented that while competitive markets reduced operating costs, wholesale price markups resulting from market power often raised consumer prices relative to regulated rates.

Locational Marginal Pricing

Locational marginal pricing (LMP) is the cornerstone pricing mechanism in organized wholesale electricity markets operated by regional transmission organizations (RTOs) and independent system operators (ISOs). The LMP at each bus in the network equals the marginal cost of serving an additional megawatt of load at that location, taking into account generation offer prices, network losses, and transmission congestion. When a constrained transmission line prevents low-cost power from reaching a high-demand area, prices diverge across the network, creating congestion rent that compensates holders of financial transmission rights. The EPA overview of electricity market frameworks distinguishes regulated markets, where LMP does not apply, from organized wholesale markets where LMP drives dispatch and settlement.

Capacity Markets and Resource Adequacy

Beyond energy markets that clear in real time and day-ahead, power system economics includes mechanisms for ensuring that sufficient generation capacity is available to meet peak demand reliably over a planning horizon of one to several years. Capacity markets, operated by RTOs such as PJM and ISO-NE, require load-serving entities to procure commitments from generators to be available during high-demand periods. Capacity payments supplement energy market revenues and are intended to support investment in peaking resources that may run only a few hours per year. The Resources for the Future explainer on U.S. electricity markets provides an accessible overview of how energy, ancillary service, and capacity markets interact to achieve resource adequacy.

Applications

Power system economics has applications across regulation, market operation, and investment planning for electric energy, including:

• Unit commitment and economic dispatch optimization in control center software
• Transmission congestion management and planning for new grid investment
• Design of demand response and energy efficiency programs under regulatory frameworks
• Renewable energy procurement, power purchase agreements, and contract pricing
• Rate design for regulated distribution utilities, including time-of-use and dynamic pricing tariffs