Modeling Approaches to Building Energy Efficiency

William Sisson, United Technologies Corporation and World Business Council for Sustainable Development

Keywords

Abstract

Buildings use a substantial portion of the world's energy. Advances in energy efficiency could therefore contribute to tackling climate change and energy security by reducing energy consumption. Many policy, technology and financial options are already available to achieve substantial energy efficiency improvements but progress has been slow and there is little consensus on the optimal combination of measures. Most attempts to address this problem have adopted a macro approach, considering likely adopted solutions in terms of efficiencies and their resulting impact at a global level.

This paper reports an alternative approach, using macro-level scenarios to feed detailed building sub-sector decision analysis. This combination of top-down scenarios and bottom-up decision modeling produces impact estimations of sector-specific policy and technology packages. For 25 selected sub-sectors, the model has produced results quantifying energy and carbon savings with financial impact, sufficient to permit aggregation to a global level. The model is unique in combining energy impact with decision making models of stakeholders for sub-sectors, as modified by policy or industry actions. This must be considered in conjunction with the systemic effects of choosing one energy efficiency option over another. In one case studied, decision making models indicate low concern for first costs of CFL's with high concern for performance, and include trade-off these decisions make on heating and cooling system energy.

In addition to decision economics, solutions selected by stakeholders must be modeled in terms of their both financial and qualitative attributes. Further, overall efficiency and corresponding economics is a systems effect; it cannot simply reflect the efficiency increase of subsystems.