Energy efficiency in buildings Case studies from around the world Case studies and most slides prepared for ESCAP by Prof. B. Mohanty

Around 50% of all electricity is used in buildings Source: OECD/IEA, 2008, Energy Technology Perspectives 2008

Energy and buildings During building construction & renovation (Embodied energy in the building materials, Energy needed during construction & renovation process) During building operation over its life span (Energy to achieve thermal and lighting comfort, Energy needed for types of appliances) years lifetime! Materials Extraction Site Assembling Transport Electricity-HVAC Power plant Solid waste Demolition OperationDemolitionConstructionPre-construction Slide prepared for ESCAP by Prof. B. Mohanty

Embodied versus operating energy P4 Manufacturing Embodied Energy Operating Energy 1. Indirect2. Direct Poor design, less comfort, higher electricity consumption By combining different techniques, small increases in embodied energy will greatly decrease operating and total energy use Linkage

Low energy office building: Malaysia Key data Gross floor area: m 2 Energy performance index: 114 kWh/m 2 /year Addition cost to construct: 5% Annual energy savings: RM Payback period: 5 years S5 Best practices and exemplary buildings Energy efficiency features Orientation & building envelope insulation Energy efficient lighting, ventilation & office appliances Energy management system Ministry of Energy, Water & Telecommunications, Malaysia

Malaysia Energy Centre Zero energy office building Key data Gross floor area: m 2 Energy performance index: 35 kWh/m 2 /year (excluding solar PV) Energy performance index: 0 kWh/m 2 /year (including solar PV) Addition cost to construct: 21% (excluding solar PV) Addition cost to construct: 45% (including solar PV) Payback: <22 years 6 Energy efficiency features Building envelope insulation & double glazing Almost 100% day-lighting & task lighting Energy efficient ventilation & floor slab cooling Energy efficient appliances Energy management system Malaysia Energy Centre

New construction: Indian Institute of Technology, Kanpur, India S7 Best practices and exemplary buildings Energy efficiency features Building envelope Cavity wall with insulation Insulated & shaded roof Double glazed & shaded windows Lighting system Efficient fixtures Efficient lamps Daylight integration Heating, ventilation and air conditioning (HVAC) system Load calculated with optimized envelope & lighting system Efficient chillers Efficient condensing system Use of geothermal cooling EPI = 240 kWh/m 2.annum EPI = 208 kWh/m 2.annum EPI = 168 kWh/m 2.annum EPI = 133 kWh/m 2.annum EPI = 98 kWh/m 2.annum Envelope optimization Lighting optimization HVAC optimization Control systems

Retrofitting/rehabilitation of government buildings: India S8 Energy efficiency retrofit in buildings Presidents Office & Residence Complex Energy audits conducted in important government buildings Presidents Office & Residence Complex Prime Ministers Office Government Offices (Power, Railways, Telecommunications, Transport) Medical Institute & Hospital Building Airport Terminals Assessed energy savings potential Varying between 25 and 46% Payback period: 1 to 4 years Implementation of recommendations Through Energy Service Companies (ESCOs)

Government support for existing residential homes: Thailand Study the house design Provide advice through expert team for improving energy efficiency Extend financial support up to 30% of the actual improvement costs S9 Best practices and exemplary buildings Support from national energy agency (DEDE) for the construction of energy efficient new residential homes Detailed design of 3 types of individual houses of different sizes and costs based on detailed study carried out by experts Construction permit given by concerned authorities in a short time

Low-cost energy efficient housing promotion: Thailand S10 Best practices and exemplary buildings OPTION A Land area: m. x m.; Built-up area: 84 m 2; Configuration: 2 bedrooms, 1 bathroom, living room, dining room, kitchen, parking for 1 car; Estimated cost (2004) 700,000 Baht

ING office building in Amsterdam One of the pioneer sustainable building Features of the building Absence of air conditioning system Use of massive 18 interior walls to act as insulator and building flushed with night air Building energy consumption one-tenth of its predecessors and one-fifth of new office building Annual energy cost savings of US$2.9 million compared to costs of additional features of US$700,000 (payback time of only 3 months) Productivity gains through lower absenteeism 11

Role of public authorities Examples of implementation in China Harbin / Heihe Rehabilitation of 6 buildings ( m 2 ) Construction of 20 rural houses 50% heating energy savings (65% in 2 buildings) Beijing Construction of m 2 of residential & commercial buildings 65% & 75% energy savings for commercial & residential buildings, respectively Shanghai Construction of m 2 of residential & commercial buildings 65% heating & cooling energy savings P12 Extremely cold Cold Cold in winter and hot in summer

Heat transfer & comfort in rural houses Heat consumption of rural houses Simulated heat consumption of a conventional rural house in Heihe area P13

Heat transfer & comfort in rural houses Heat consumption of rural houses Simulated heat consumption of a well insulated rural house in Heihe area: Most insulated house constructed with following features 18 cm EPS insulation in walls 12 cm EPS insulation in floor 18 cm EPS + 20 cm wood chips in the roof above the ceiling Triple glazing plastic windows + well ceiled night times curtains Improved air tightness with inlet pipes for fresh hygienic air Assumption: the whole house is maintained at 18°C throughout winter Average coal consumption of the house: 2.75 tons/year This represents 72% savings in fuel consumption! P14

Heat transfer & comfort in rural houses Heat consumption of rural houses Simulated heat consumption of a well insulated rural house in Heihe area P15

Heat transfer & comfort in rural houses Comparison of heat consumption Results of measurements made on insulated houses in Heihe area: A well insulated house uses 2.5 times less energy/m 2 than the conventional one; A very well insulated one uses 4.4 times less energy/m 2 than the conventional one

Heat transfer & comfort in rural houses Parameters of thermal comfort Parameters with significant influence on thermal energy use in winter Internal air temperature Inside building envelope temperature (walls, glazing, roof, floor) Mean radiant temperature, which is the temperature effectively felt by occupants Internal relative air humidity that should be kept below 60% for better comfort and for avoiding condensation and moisture appearance on inner walls; Velocity of air streams on occupants with air colder than skin temperature (about 32°C) should be kept below 0.2 m/s; Temperature gradient in the room should be kept minimal by preferring radiant heating systems rather than convective ones

Office building in Melbourne, Australia Refurbished with 87% of the building structure recycled and awarded 6 green star- office design rating Project achievements: 65% reduction in energy use compared to use prior to retrofit 88% reduction in water use compared to average 72% reduction in sewer discharge 54% waste reduction compared to average Energy consumption 2009: 69kWh/m²/per annum 20pages/key_features.html 20pages/key_features.html 18

Office building Melbourne, Australia Energy: Lighting Controls Lighting Building Management System Mixed mode air-conditioning (natural ventilation and gas-driven air- conditioning units) Building Envelope Efficiency BMS Occupancy Control & Car Park Ventilation Central Vacuum System Embedded Generation and Demand Management Monitoring & Verification Solar Arrays Solar Hot Water Interface to Security Lift Upgrade Water: Accredited Low Flow Taps Accredited Waterless Urinals Dual Flush Toilets Electronic Taps Grey Water / Rainwater Harvesting Sprinkler Water Recovery Waste Management 3 bin system Indoor Environment Quality Automated Windows and, Natural Ventilation Mixed Mode & Openable Windows Weather Station Materials & Indoor Air Quality Dedicated Tenants Exhaust Riser Transport Introduction of cycle racks and cycle facilities Reduction in number and sizes of car spaces 40 Albert Road is close to major transport hubs and public transport

Mongolia Approximately 250,000 people (20% of the urban population) live in prefabricated buildings in Ulaanbaatar. Pilot project of one apartment building to determine potential energy savings. It was found that up to 40 % of the heating energy can be saved. A potential 60% or more is also possible with consumption-oriented heating tariffs. Source: D + C journal, GTZ article, accessed from Retrofitting prefabricated buildings - Ulaanbaatar

Source: Thermo-technical rehabilitation of pre-cast panel buildings in Ulaanbaatar, pre-feasibility study, City Government of Ulaanbaatar, Cities Development Initiative for Asia (CDIA), GTZ, 2009

Scaling up to all of Ulaanbaatar The potential savings of scaling this pilot up to all prefabricated buildings in Ulaanbaatar: 426 buildings, a total of 2,973,840 m 2 floor-space; Estimated heat energy consumption in 2007: 1,040,844,000 kWh/year. Estimated heat energy consumption after retrofitting: 297,384,000 kWh/year Energy saved : 743,460,000 kWh/year Coal saved: 561'724 tonnes/year or 8320 wagons CO 2 saved: 842'586 tonnes/year Financial savings: 8,987,576,320 (USD 7,681,689 (2007) USD 6,454,737 (Mar 2010)) Source: GTZ/UDCP, Energy saving potential through thermo-technical rehabilitation of precast panel buildings in Ulaanbaatar, Mongolia, 2007

Thank you!! Kelly Hayden Energy Security Section ESCAP

Barriers to energy efficiency in buildings Decentralized nature of the building sector Lack of interaction Misplaced incentives Lack of information Transaction costs Deficient design process Energy prices and market barriers