What Is Power Generation Planning?

Power generation planning is the process of determining what new generating capacity a power system requires, of what technology type, in what location, and on what timeline, to meet projected electricity demand reliably and economically over a planning horizon of ten to thirty years. It is a core function of electric utilities, independent system operators, regional planning bodies, and government energy agencies. Decisions made in generation planning determine the capital structure and fuel mix of the system for decades, with direct consequences for electricity prices, carbon emissions, and grid reliability.

The discipline draws from optimization theory, probabilistic risk analysis, power system engineering, and energy economics. Modern generation planning must account for the rapid cost declines of wind, solar, and battery storage, the retirement of aging thermal plants, and increasingly stringent environmental regulations.

Resource Adequacy Assessment

The foundational question in generation planning is whether the system has enough dispatchable capacity to meet peak demand with an acceptable probability of failure, a property called resource adequacy. Planners assess adequacy using metrics such as the Loss of Load Probability (LOLP) and Loss of Load Expectation (LOLE), which estimate how often, on average, available generation is expected to fall short of demand. The standard adopted by many North American reliability regions is no more than one loss-of-load event per ten years. With growing penetration of variable renewable energy, adequacy assessment has become more complex because the contribution of wind and solar to meeting peak load depends on probabilistic availability during high-demand hours. Lawrence Berkeley National Laboratory has published a detailed guide for improved resource adequacy assessments that addresses these methodological challenges, including the treatment of storage and demand response in adequacy calculations.

Long-Term Capacity Expansion

Capacity expansion planning uses optimization models to identify the least-cost portfolio of new generation and storage investments that satisfies demand and reliability requirements over the planning horizon. These models minimize total system cost, including capital costs, operating costs, and fuel costs, subject to constraints on reliability, transmission, emissions, and fuel availability. Outputs of a capacity expansion study identify the preferred technology mix, build year, and location of new plants as well as the optimal retirement schedule for existing units. The U.S. Department of Energy's best practices guide for Integrated Resource Planning documents methodologies used by utilities and regulators to structure these analyses, including scenario planning, sensitivity analysis, and stakeholder engagement.

Environmental and Regulatory Constraints

Generation planning does not operate on cost and reliability criteria alone. Environmental regulations impose emissions limits on existing plants and, in some jurisdictions, mandate the retirement of coal or oil-fired units by specific dates. Renewable portfolio standards and clean energy standards require a minimum share of generation from qualifying resources, shifting the technology mix independently of cost signals. Carbon pricing mechanisms, where implemented, make emissions-intensive generation less competitive by internalizing the cost of greenhouse gas releases. Research published through the OSTI.gov repository on resource adequacy in electricity markets with renewable energy analyzes how high renewable penetration interacts with capacity market design to achieve both reliability and decarbonization goals simultaneously.

Applications

Power generation planning has applications in a wide range of disciplines, including:

• Integrated resource planning processes filed with state utility regulators
• Transmission expansion planning, which is coupled to generation location decisions
• National energy policy and long-term electricity sector decarbonization roadmaps
• Project finance and capital markets, which rely on planning studies to assess investment risk
• Grid resilience analysis under climate change scenarios affecting demand and fuel supply