MEDEE 2: A Model for Long-Term Energy Demand Evaluation

This paper describes a simulation model, MEDEE 2, designed to evaluate the long-term energy demand of a country, in combination with a scenario description of the main aspects of the country's social, economic, and technological evolution. This approach considers in a detailed way a national energy demand pattern and breaks down the total demand in a multitude of end-use categories (e.g., residential space heating, service sector cooling, gasoline for intercity cars). By means of this detailed investigation of energy demand we are better able to take into account the influence on energy demand of changes in social needs, economic growth, government policies, or technologies, especially in the present context of high energy prices. In addition, it makes possible the identification of the potential market (i.e. maximum demand that can be technically met) of each final energy form (e.g., electricity, coal, gas, solar, oil products, and district heat). The model calculates useful energy demand in each end-use category for which several energy forms can be used, thus determining the substitution possibilities in energy use. This useful energy matches the energy service needed by the consumer (e.g., heat, mechanical energy). Useful energy differs from final energy, purchased by the consumer, by the efficiency of the enduse appliances. Each useful energy demand is then converted into a demand for final energy, taking into account the fuel mix (i.e., the fraction of the demand supplied by each fuel) and the end-use efficiencies of each fuel. This approach-estimating useful energy-is necessary if one wants to account for the differences in fuel efficiencies: for the same service (let us say 1 kwh of heat) the final demand will vary according to the fuel type because of these different efficiencies (e.g., 1 kwh of electricity, 1.35 kwh of gas, 1.50 kwh of oil, and 2 kwh of coal). The total final demand is projected in MEDEE 2 for the following types of final energy forms: fossil fuel '(substitutable use of coal, oil, and gas), electricity, motor fuel, coke, feedstock, solar, and district heat. MEDEE 2 is driven by a set of scenario elements, the evolution of which is defined in a scenario. The core of the scenario is a characterization through these elements of the development pattern of the country under consideration (life-styles, economic growth patterns, etc.). The scenario description is complemented with technological parameters (e.g., insulation standards, efficiencies, fuel mix), the evolution of which is specified in a way consistent with the macroeconomic assumptions.