Carbon Dioxide Emission Reduction and Cost Benefit Analysis of Building Energy Management System - The Case of Taipei 101

Abstract

In the period of environmental consciousness countries and environmental organizations pay increasing attention to environmental protection issues such as global warming The reason of global warming is from the emission of the greenhouse gas (GHG) mainly resulted by carbon dioxide (CO2) Thus reducing CO2 becomes a priority in controlling GHGs The largest source of CO2 emissions is the use of energy industrial transportation residential activities Nowadays with the addition of the population and urbanization the quantity of the residential and commercial buildings in cities is growing rapidly At the same time with the addition of the buildings the energy consumption and CO2 emission is growing rapidly and reducing the CO2 emissions which made by the building had became one of the priority projects In addition many processes are associated with the raw materials such as the energy which supports the electricity and the water supplements With the increase of urbanization the demand of raw materials increase simultaneously and the market pushed raw material prices to unknown levels This motivation also increases the demand for the building using energy saving system in order to reduce the maintenance costs Many buildings have installed building energy management system (BEMS) which is used via sensors to aware environmental status to understand user’s status and activities and gathers the data of various sensors and equipment states In a case of an abnormal situation the sensor can send the signal via the network to communicate to the server which in turn uses the actuator to control the equipments to reduce the unnecessary waste in the building BEMS helps the building energy manager use these informational tools to control building energy consumption and make managerial jobs become easier and more efficient In order to achieve the Leadership in Energy and Environmental Design (LEED) for existing buildings in the category of operations & maintenance (LEED-EBOM) Green Building Mark’s platinum level started in 2009 Taipei 101 has endeavored in efficient energy usage in green building operation and has done a series of activities to reduce the energy consumption and CO2 emissions of the public area of the office building To increase energy use effectively a lot of inefficient equipments have been replaced and improved into the energy efficient equipments and unnecessary programming of building operating were modified and optimized For example the lamps in the public area are changed from the original T8 lamps to the T5 or LED lamps and ventilation operating hours of air condition system were modified to reduce electricity consumption In the same year of the LEED certification process Taipei 101 commissioned Siemens to build the energy monitoring and control system (EMCS) which monitors analyzes and controls the facilities status of five subsystems of air conditioning illumination electrical water and other monitoring system to increase energy efficiency with advanced building automation and optimization Through the complete planning the BEMS operates and controls the HVAC and other facilities in the building and eventually makes overall energy usage to be optimization By doing so Taipei 101 has excellent performance on energy efficiency and CO2 reduction and corrects management system This study takes the tallest certified green building Taipei 101 building the landmark skyscraper in Taiwan as the research object and finds out the effectiveness of the BEMS on the building The data of Taipei 101 energy usage before and after the BEMS installation and operation energy saving equipment replacement project national electricity and water emission factors electricity and water prices and CO2 trading price are collected The BEMS data include system cost and the electricity consumptions of five subsystems which are monitored by BEMS The data of eleven equipment replacement projects include equipment costs and electricity and water consumptions of three systems which were replaced during 2009 to 2011 The electricity and water saving effect and CO2 emission reduction effect and their cost and benefit analysis (CBA) of BEMS and equipment replacement are conducted for the system to investigate the investment on installing BEMS The CBA of the BEMS in the time periods of ten years twenty years and thirty years under three scenarios (including optimistic ordinary and pessimistic) with different assumptions of different increases in electricity saving and operating costs are conducted to derive the values of net present value (NPV) internal rate of return (IRR) benefit-cost ratio (BCR) and payback period (PP) Overall the BEMS is worthy to invest for Taipei 101 The results show that the installation of BEMS not only reduces energy consumption and CO2 emissions effectively but also reduces the enterprise’s cost and incurs the benefit to the enterprise when the time period of more than ten years and the scenario better than ordinary scenario are considered in the analysis or when the benefits of CO2 emission reductions are considered Further the CBA results improve with higher NPV IRR and BCR values and shorter PP when longer time periods or better scenarios are considered

Date of Award	2014 Aug 6
Original language	English
Supervisor	Chun-Hsiung Liao (Supervisor)