Quoted from: http://webarchive.iiasa.ac.at/Research/ENE/model/message.html

MESSAGE is a systems engineering optimization model used for medium- to long-term energy system planning, energy policy analysis, and scenario development (Messner and Strubegger, 1995). The model provides a framework for representing an energy system with all its interdependencies from resource extraction, imports and exports, conversion, transport, and distribution, to the provision of energy end-use services such as light, space conditioning, industrial production processes, and transportation.

Scenarios are developed by MESSAGE through minimizing the total systems costs under the constraints imposed on the energy system. Given this information and other scenario features such as the demand for energy services, the model configures the evolution of the energy system from the base year to the end of the time horizon. It provides the installed capacities of technologies, energy outputs and inputs, energy requirements at various stages of the energy system, costs, emissions, etc.

In addition to the energy system the model includes also the main other greenhouse-gas emitting sectors agriculture and forestry. The framework covers all greenhouse gas (GHG)-emitting sectors, including agriculture, forestry, energy, and industrial sources for a full basket of greenhouse gases and other radiatively active gases. MESSAGE is used in conjunction with MAGICC (Model for Greenhouse gas Induced Climate Change) version 4.1 (Wigley, 2003) for calculating internally consistent scenarios for atmospheric concentrations, radiative forcing, annual-mean global surface air temperature and global-mean sea level implications.

The model’s principal results comprise, among others, estimates of technology-specific multi-sector response strategies for specific climate stabilization targets. By doing so, the model identifies the least-cost portfolio of mitigation technologies. The choice of the individual mitigation options across gases and sectors is driven by the relative economics of the abatement measures, assuming full temporal and spatial flexibility (i.e., emissions-reduction measures are assumed to occur when and where they are cheapest to implement).

The degree of technological detail in the representation of an energy system is flexible and depends on the geographical and temporal scope of the problem being analyzed. A typical model application is constructed by specifying performance characteristics of a set of technologies and defining a Reference Energy System (RES) to be included in a given study/analysis that includes all the possible energy chains that the model can make use of (see Figure 1). In the course of a model run, MESSAGEthen determines how much of the available technologies and resources are actually used to satisfy a particular end-use demand, subject to various constraints, while minimizing total discounted energy system costs.

The global MESSAGE model hosts 11 macro-regions and has a time horizon until 2100 that is divided into 10-year steps. It provides information on the utilization of domestic resources, energy imports and exports and trade-related monetary flows, investment requirements, the types of production or conversion technologies selected (technology substitution), pollutant emissions, inter-fuel substitution processes, as well as temporal trajectories for primary, secondary, final, and useful energy.

MESSAGE includes endogenous technology learning (ETL) for various technologies using a Mixed Integer Programming (MIP) approach. ETL can either be used with the 11-regional MESSAGE model or with a more aggregated 4-regional version.

MESSAGE is also an integral part used for developing the integrated assessment modeling framework of the Greenhouse Gas Initiative at IIASA (see Riahi and Nakicenovic (eds.) 2007).