Energy use in commercial building in China : Current situation and future scenarios

While China’s 11th Five Year Plan called for a reduction of energy intensity, whether and how the energy consumption trend could be changed in a short time has been hotly debated. Th is research intends to evaluate the impact of a variety of scenarios of GDP growth, energy elasticity and energy effi ciency improvement on energy consumption in commercial buildings in China using a detailed China End-use Energy Model. China’s offi cial energy statistics have limited information on energy demand by end use; further, China uses a diff erent classifi cation system for energy reporting, so offi cial sectoral energy breakdown has long been questioned. It is a particularly pertinent issue for building energy consumption, for example, in China’s statistics it only accounts for about 13 % of the total, while it is about 30 % in other countries. Th erefore, it is crucial to evaluate and understand the reality, rather than simply accepting it, as many of the energy analysts have done. Th e authors have applied reasoned judgments, based on experience of working on Chinese effi ciency standards and energy related programs, to present a realistic interpretation of the current energy data. Th e bottom-up approach allows detailed consideration of end use intensity, equipment effi ciency, etc.—as a way to apply judgments, thus facilitating assessment of impacts of specifi c policy and technology changes on building energy use. Th e results suggest that 1) commercial energy consumption in China’s current statistics is underestimated by about 44 % and the fuel mix is misleading; 2) energy effi ciency improvements will not be suffi cient to off set the strong increase in end-use penetration and intensity in commercial buildings, and energy (particularly electricity) intensity in commercial buildings will increase; 3) diff erent GDP growth and elasticity scenarios could lead to a wide range of fl oor area growth, and therefore, signifi cant impact energy consumption in commercial buildings. Introduction China’s 11th Five-Year Plan (FYP) sets an ambitious target for energy effi ciency improvement: energy intensity of the country’s gross domestic product (GDP) should be reduced by 20 % from 2005 to 2010 (NDRC, 2006). Whether and how energy consumption might be changed have been hotly debated, considering the fact that energy consumption has grown more rapidly than GDP in the last fi ve years; however, if the recent trend continues, not only will it jeopardize China’s development goals, but also create signifi cantly greater adverse environmental impacts and introduce a huge “unexpected” disturbance to the global energy and climate system. Experience in developed countries shows that energy intensity reduction in the industrial sector can be achieved through energy effi cient technologies and structural change. Energy effi ciency improvements in commercial buildings however are likely to be off set by growing demand for higher levels of energy services as living standards rise, including more space heating and cooling, brighter lights, more hot water, and more offi ce equipment. Th ese responses to the demand for higher functional standards make it diffi cult to reduce energy intensity in the building sector in China. However, higher equipment Bressand, Florian Zhou, Nan Lin, Jiang 5,312 BRESSAND ET AL 1066 ECEEE 2007 SUMMER STUDY • SAVING ENERGY – JUST DO IT! PANEL 5. ENERGY EFFICIENT BUILDINGS effi ciency and stronger policies can together act to slow down the growth of energy consumption in buildings. Th is research intends to evaluate the impact of a variety of scenarios in GDP growth, fl oor space elasticity, and energy effi ciency improvement on energy consumption in commercial buildings in China using a detailed China End-use Energy Model (Lin et al, 2006). At the same time, this analysis off ers a realistic interpretation of the current energy data for the building sector. Methodology Integrated assessment models have been used to project both baseline and alternative scenarios. Two general approaches have been used for the integrated assessment of energy demand and supply – the so-called “bottom-up” and “top-down” approaches. We used LEAP (Long-range Energy Alternatives Planning System) to build our China commercial end-use model, based on a bottom-up approach that allowed a detailed consideration of end-use intensity, equipment effi ciency, and technology shares—as a way to apply reasoned judgments to sectoral energy statistics, and to form a base to facilitate the development of energy scenarios and assess impact of policy and technology choices on building energy use. A baseline scenario that incorporates targets stated in China’s offi cial plans and business-as-usual technology improvement was developed fi rst, and a contrasting green growth scenario was created to examine the impact of stricter policies. Upon these two scenarios, diff erent GDP growth and elasticity scenarios have been created to evaluate the impact of a variety of scenarios in GDP growth, energy elasticity and energy effi ciency improvement on energy consumption in commercial buildings. Commercial energy use is dominantly driven by fl oor area growth. GDP is not used as a direct driver but rather than a force that drives the fl oor area growth. It is also shaped by a variety of factors, including building types, penetration of enduses such as space heating and cooling, end-use energy intensity, the choice of technologies, and energy effi ciency of each technology. Omitting repetitive subscripts for the energy intensity terms, these can be represented as seen in Equation 1.