Core Bundles of Technologies to Achieve Deep Energy Retrofit with Major Building Renovation Projects in Europe, the United States, and China

摘要

Numerous pilot projects conducted all over the world have demonstrated that energy use in commercial and public buildings can been reduced by more than 50% after renovation. In fact, some renovated buildings have met the Passive House Institute energy efficiency standard or have even achieved a net zero energy state (Zhivov etal. 2015). Research (IEA 2009;ASHRAE 2015) has identified more than 400 energy efficiency measures that can be used when buildings are retrofitted. Such measures include those related to the building envelope, mechanical and lighting systems, energy generation and distribution, and internal processes. Implementation of some individual measures (such as building envelope insulation, improved airtightness, and cogeneration) can significantly reduce building heating and cooling loads or minimize energy waste, but require significant investments with long paybacks. However, when a limited number of core technologies are implemented together ("bundled"), they can significantly reduce energy use for a smaller investment and thereby provide a faster payback. Characteristics of some of these core technology measures depend on the technologies available on an individual nation 's market, on the minimum requirements of national standards, and on economics (as determined by a life cycle cost [LCC] analysis). In addition to these measures, requirements related to building envelope-related technologies (e.g., insulation levels, windows, vapor and water barriers, and requirements for building airtightness) depend on specific climate conditions. National teams associated with the International Energy Agency Energy Conservation in Buildings and Communities Program (IEA EBC) Annex 61, Business and Technical Concepts for Deep Energy Retrofit of Public Buildings (EBC 2015), have studied such conditions by computer simulation (Case et al. 2016; Rose et al. 2016; Riel et al. 2016; Yao et al. 2016). This paper summarizes the results of these studies, which will be used in an IEA Energy in Buildings and Communities (EBC) Programme Annex 61, Deep Energy Retrofit-Case Studies (IEA 2015). The key to making a deep energy retrofit (DER) cost effective is to time the retrofit as part of a major building renovation that already has allocated funds, including those required to meet minimum energy requirements. Since there is an overlap between the funds allocated for the retrofit and those required for the DER, achieving the DER requires only an incremental cost because the DER is evaluated based on a bundle of core technologies, not on individual energy efficiency measures. To evaluate the cost effectiveness of DER project using bundles of core technologies, compared to a typical major building renovation based on minimum energy requirements, this paper proposes the use of net present value (NPV) of the differences in energy savings, maintenance, and insurance costs and other operational costs and revenues to estimate the budget increase limit, which makes the DER project LCC effective. Since most of parameters required for an LCC analysis differ not only by the individual country but also within the country (first costs and labor rates, energy rates, life of the project, and inflation and discount rates), the concept of scalar Ratio (McBride 1995) is used to calculate limitations in renovation budget increase.