Abstract The energy system-economic analysis techniques developed for strategic planning encompass the technological features of the energy system as well as economic and environmental factors. The economic basis for these techniques is market clearing equilibrium, and models are specified for future planning years of interest. They are especially helpful for analyzing policies having long-run effects on energy supplies, prices, technologies, and final demands for energy. The major analytic components of this methodology for strategic planning in the energy sector include the Reference Energy System, single and multiple time period energy system optimization models, and an energy input-output model of the national economy. Policy applications of these techniques include R&D planning, interfuel substitution studies, energy demand analysis, oil stockpiling strategies, industry impacts of different energy scenarios, and analysis of life style changes.