Dimensions of ecologically sustainable development

Transcription

1 Green Buildings and their Financial Feasibility 12 August 2010 By: Mili Majumdar The Energy and Resources Institute (TERI) Dimensions of ecologically sustainable development Resources Water Energy Trees/vegetation Land and soils Pollution Water pollution Air pollution Soil degradation Erosion Solid waste Conservation & augmentation Environmental health Green..the way to build 1

2 A Green Building Minimizes depletion of natural resources during its construction and operation Minimizes pollution: Water pollution, Air pollution, Soil degradation, Erosion, Solid waste Uses minimum energy to power itself Uses efficient equipments: lighting, air conditioning, etc. Maximizes the use of renewable energy sources Uses efficient building materials and construction practices Uses efficient waste and water management practices Provides comfortable and hygienic indoor environment Benefits of Green Buildings Minimal impact on site and surroundings Erosion control Storm water management Pollution control Tree protection Heat island control 2

3 Benefits of Green Buildings Saves water by upto 30-40% By reducing irrigation water requirement Use of efficient fixtures Rain water harvesting Waste water treatment on site Recycle and reuse of water Benefits of Green Buildings Saves energy by 40-50% Minimize building energy demand through: Solar Passive Design Use of efficient building systems Maximum use of renewable energy 3

4 Benefits of Green Buildings Solid waste management Reduction in waste during construction Efficient waste segregation at source Suitable storage and disposal at building level Resource recovery from waste Benefits of Green Buildings Use of sustainable building materials Use of recycled material: Fly ash, blast furnace slag Adopting efficient technologies Use of low-energy materials Very high energy High energy Medium energy Low energy Aluminum, stainless steel, plastics, copper Steel, lead, glass, cement, plaster board Lime, clay bricks and tiles, gypsum plaster, concrete (in situ, blocks, pre-cast) Sand, fly ash, blast furnace slag 4

5 Benefits of Green Buildings Minimal negative impact on people Healthy and productive work environment Clean environment for construction workers Day lighting/natural ventilation Universal accessibility National Rating System: GRIHA Green Rating for Integrated Habitat Assessment Tool to facilitate design, construction, operation of a green building,and in turn.measure greenness of a building in India Set of 34 criteria 100 (+4 innovation points) point system with differential weightage on various criteria

6 Why GRIHA? All Green Building aspects covered under GRIHA Rating What gets measured gets managed Policies/programs to mainstream green construction Energy Conservation Act 2001 enacted Energy Conservation Building Code (ECBC)2007 launched Star rating of existing buildings launched Ministry of Power/Bureau of Energy Efficiency empowered to mandate ECBC Environmental Clearance from the Ministry of Environment and Forests/State Environment Impact Assessment Authority mandatory for all large constructions Resource (energy, water) efficiency integral part of clearance Convergence is crucial to implementation and mainstreaming Ministry of New and Renewable Energy incentivises GRIHA programme National green building rating system GRIHA launched National Action Plan on Climate Change Mission on Sustainable Habitat GRIHA Scoring Weights Materials and construction technology 17% Site planning 17% Health and well being 9% Waste management 5% Water 15% Energy(end use) and Renewable Energy 37% 6

7 5 Star Rated GRIHA Building in IIT Kanpur Trees preserved and protected Solar PV and Solar Thermal systems N-S Orientation with shading (roof/window) Outdoor solar lights Lesser paving Incremental cost 17% Energy savings 52% Payback period :3 years Common wealth Games Village Sustainable site planning (compensatory afforestation, topsoil preservation, etc) Water efficient landscape by adopting native species, efficient irrigation systems and limiting turf areas. Building water consumption reduced by use of high efficiency and lowflow fixtures Energy efficiency measures such as high performance glass, roof insulation, energy efficient lighting and variable refrigerant volume based air conditioning shall reduce the energy consumption of the apartments significantly Solar photo voltaic system is proposed to meet 10% of total energy requirement for internal lighting Waste water recycling and solid waste management system are being planned 7

8 Station cum commercial complex for Delhi Metro Rail Corporation(16 hour /day use) EPI (Base case):522 kwh/sq m /year EPI (ECBC roof and glass): 469 kwh/sq m /year (10% savings) EPI (ECBC light power density): 424 kwh/sq m /year (18% savings) Challenges: Builder invests tenant benefits (overcome through committed leadership) Design team may not accept change (overcome through continuous discussion process) Owner may not put up all the systems (overcome through laying down tenant/buyers guidelines) EPI (ECBC HVAC): 331kWh/sq m /year (36% savings) EPI (Heat recovery): 268 kwh/sq m /year (48% savings) Tonnage of AC brought Are Green Buildings Financially Feasible? Description of study conducted by TERI 7 green rated buildings selected as case studies Required building data collection (through primary survey, consultation with subject experts, basic thumb rules for filling in data gaps) Green case and base case established Data analysis 8

9 Are Green Buildings Financially Feasible? Description of study conducted by TERI Life of building: 25 years Values used for calculation of present value factors Inflation rate: 4.9% Nominal discount rate:16% Real discount rate: 10.6% Escalation rates: 7.6% Costs Single costs: Initial investment costs, capital replacement costs and resale value of building Uniform annually recurring costs: Operation & Maintenance costs Non-uniform annually recurring costs: Energy costs of the building Study results Comparison of initial cost ( per sq.m.) of Green vs conventional buildings Cost/sqm C omparison of cost/sqm for Green building vs C onventional building Cost/sqm for Green buildings Cos t/s qm for Conventional buildings Range of initial investment cost for Green Buildings= Rs /sqm Range of initial investment cost for Conventional Buildings= Rs /sqm 9

10 Study results Increment in initial cost of Green vs conventional buildings Increment in Initial Investment for Green case as compared to conventional case Initial investment cost (Crore Rupees) % Green Case Conventional Case 17% 12% 25% 4% 17% 10% Case Studies Initial investment cost for Green buildings is higher as compared to conventional buildings: incremental cost ranging from 4-32 % Study results Components of green building cost increment Green rating & consultancy, 12% Incremental cost components Envelope, 39% Systems, 35% Lighting & controls, 15% Building envelope Roof & wall insulation, high performance glazing 39% Systems (HVAC system, Electrical system, BMS) Lighting& controls Efficient chillers, motors & pumps, VFD, economizers, heat recovery wheel, BMS Energy efficient lamps & fixtures, controls (Daylight & occupancy sensors) 35% 15% Towards green rating 12% 10

11 Study result: Green building cost increment -Major contributors Building envelope, Efficient systems and Lighting Reduction in energy consumption due to these: EPI (kwh/sqm per annum) EPI 500(kWh/s% reduction Base building Envelope optimization Lighting optimization Efficient chiller Controls for HVAC system Base building Envelope optimization Lighting optimization EPI (kwh/sqm per annum) % reduction ECBC interventions Efficient chiller Controls for HVAC Base Case Final case Total % Reduction EPI (kwh/ m2 per annum) Study results Maximum cost increment due to: Efficient envelope, systems and lighting Which cause maximum energy savings, thus reduction in annual electricity bills Which are ECBC recommendations 11

12 GRIHA Compliant Building= ECBC compliant Energy saving potential in a ECBC and GRIHA compliant building 37% 45% ECBC Compliance: Insulation High Performance glass Controls Efficient electrical, mechanical and lighting systems Incremental cost: 15% Payback period < 5 years kwh/yr 0 conventional building ECBC compliant building GRIHA compliant building GRIHA Compliance: ECBC + Passive principles (shading, orientation, controlled glass area) Higher indoor design conditions (higher by 1 deg C) Optimized lighting design No further incremental cost Payback period: < 4 years Study results Life cycle cost comparison of Green vs Conventional Building Comparison of Life cycle costs over 25 years : Green vs Conventional Case Cost (Crore Rs.) Life cycle cost - Green Case Life cycle cost -Conventional case Life cycle cost of Green buildings is lower as compared to conventional buildings 12

13 Study results Payback period Comparison between payback periods of different case studies 3 Years Discounted payback periods ranging from 1 to 3 years Study results Financial feasibility assessment of Green Buildings Comparison of SIR & AIRR SIR AIRR (%) Savings to investment ratio ranging from 1.9 to 15.3 Adjusted internal rate of return ranging from 19-29% 13

14 Low energy strategies: for low income groups Silkworm rearing house: Bangalore Thermal comfort requirement: Chawki room: 25 to 28 deg C with 70-90% RH Rearing room: 23 to 25 deg C with 70-80% RH Non uniform heating/cooling leads to loss in 50-70% of yield 14

15 External methods used to decrease the temperature False ceiling with thermocol False ceiling with thermocol False ceiling with thermocol False ceiling with wooden logs Wet gunny cloth hanged in corridor Wet gunny cloth hanged in door and windows Wet gunny cloth hanged in windows Coconut leaves shading to doors and windows Wet sand bed with ragi seeds sown near bottom ventilators Solar passive silkworm rearing house for enhanced productivity Strategies for summer: Roof pond with insulation Insulated wall and roof Wall shading Solar chimney on south wall with adjustable vents (to improve ACH in the rearing room) Air Inlet from north wall covered with wet gunny bags for added humidity 15

16 South view of the rearing house Architectural design of the rearing house 16

17 Solar passive silkworm rearing house for enhanced productivity Strategies for winter: Insulated wall and roof Retractable shading Trombe wall on south wall with adjustable vents Air Inlet from north wall closed Thermal performance predicted 17

18 TERI University: Usage of multiple low energy cooling techniques: (thermal storage, earth air tunnel, Variable refrigerant flow system) Thank You 18