Sustainable Building Energy Efficiency Retrofit for Hotel Buildings Using EPC Mechanism in China˖Analytic Network Process (ANP) Approach
Sustainable Building Energy Efficiency Retrofit for Hotel Buildings Using EPC Mechanism in China˖Analytic Network Process (ANP) Approach
Abstract
Building Energy Efficiency Retrofit (BEER) is considered as a valuable way to improve energy efficiency of high-energy-consumption buildings. Sustainable BEER helps integrate sustainable development strategy into existing buildings and retrofit projects. To ensure BEER projects that can fulfill the sustainable development strategy, Energy Performance Contracting (EPC) is one possible market mechanism to deliver energy efficiency projects. Sustainable BEER under the EPC mechanism is a comprehensive system which involves the various demands of sustainable dimensions, performance criteria and groups of project success factors, making multi-criteria decisions become a challenging problem for decision makers. This paper aims to examine the interrelationships of sustainable BEER by focusing on an existing hotel building. EPC mechanism is applied in the case study and an effective Analytic Network Process (ANP) approach is also employed in the research. The result indicates that sustainable BEER in hotel buildings under the EPC mechanism is mainly determined by project control mechanism, available technology, organizing capacity of the team leader, trust, accurate Measurement and Verification (M&V), and team workers’ technical skills. Decision makers should dedicate more attention to these aspects. From the research findings, several policy implications are proposed in this paper. Keywords: Building energy efficiency; retrofit; Energy performance contracting (EPC), ANP
1 Introduction
Building Energy Efficiency Retrofit (BEER) is defined as a project for reducing the operational energy use in buildings through building envelope improvement and mechanical systems upgrades, while preserving the comfort of the indoor environment. BEER could reduce energy expenditures and minimizes emissions (Sun & Liu, 2007; Han et al., 2006; Xu et al., 2009). Hotel buildings, as a high energy-consuming type of public building, offer much opportunity for energy efficiency improvement (Xu et al.,2012; Zhou et al., 2008; Xue, 2007). A survey in Beijing showed that the electricity consumption was 100-200 kWh/(m2 .a) (Xue, 2007). The range was 55-144.3 kWh/(m2 .a) in Chongqing in 2006 (Zhou et al, 2008). When conducting a BEER project, the project delivery process should be considered. Energy performance contract, provided by Energy Service Companies (ESCOs), has been used as a market mechanism to deliver energy efficiency projects, and is a turnkey service that provides customers with a comprehensive set of energy efficiency, renewable energy and distributed generation measures intended to improve energy performance and cost efficiency of facilities (Seefeldt, 2003; NAESCO, 2007). The EPC mechanism first emerged in the US in 1970s and was introduced into China in 1990s (Shen, 2007). EPC mechanism has developed fast in China and more and more energy efficiency projects have been implemented using this mechanism. This research focuses on BEER in hotel buildings using the EPC mechanism. Recently, much attention has been paid to the issue of sustainable retrofitting. Keeping and Shiers (1996) proposed the “green” refurbishment concept and analyzed the potential benefits of a “green” approach to building refurbishment. Sobotka and Wyatt (1998) applied the principles of “sustainable development” to a renovation of apartment buildings. Sitar et al. (2006) considered a model of sustainable renovation for multi-apartment buildings. Mickaityte et al. (2008) presented a concept model of sustainable building refurbishment, which provides excellent opportunities to reduce energy consumption and encourages the implementation of other sustainable
2 The ANP structure
The process of the ANP comprises the following four steps ( Saaty, 1996; Saaty, 2001; Saaty, 2005): (i) Model construction: A problem is decomposed into a network in which nodes corresponds to clusters. (ii) Pairwise comparisons and local priority vectors: In this step, the elements are compared pairwisely with respect to their impact on other elements. Step 3 Supermatrix formation: The local priority vectors are entered into the appropriate columns of a supermatrix, which is a partitioned matrix in which each segment represents a relationship between two clusters. (iv) Final priorities: the final result could be calculated based on previous steps. Before the model was developed, the key performance indicators (KPIs) for sustainable BEER in hotel buildings and the critical success factors (CSFs) of the EPC mechanism had been identified in the authors’ previous research (Xu et al.,2012; Xu & Chan, 2013; Xu et al., 2011). Six KPIs and six CSF clusters with 21 CSFs were identified The relationships among KPIs and CSFs were also examined in previous research of the authors (Xu & Chan, 2013). An ANP structure is constructed in Fig. 2 based on these relationships and illustrates two components: the control hierarchy and networks. Six key performance indicators were selected to measure the sustainable performance of BEER in control hierarchy. The networks part is much more complicated, containing six sub-networks of CSFs corresponding to the six KPIs, which reflects the contribution and affects on sustainable performance of BEER
