Dr. B. V. Venkatarama Reddy Professor, Dept of Civil Engineering, - - PowerPoint PPT Presentation

• Dr. B. V. Venkatarama Reddy

Professor, Dept of Civil Engineering, Indian Institute of Science, Bangalore

THIS PRESENTATION WAS SHARED BY FOR THE SESSION: “Embodied Energy and the Life Cycle Approach” DURING ANGAN 2019

• B. V. Venkatarama Reddy

Professor Department of Civil Engineering & Centre for Sustainable Technologies Indian Institute of Science Bangalore – 560 012, INDIA

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Energy in Buildings & Sustainability – an overview

Lecture delivered at ‘ANGAN 2019’, 11 September 2019, New Delhi

Limited resources

Mass of resources: 6 x 1021 t

Planets Material & Mineral wealth

• Limited
• Non-renewable

The Planet Earth Finite size Emissions Anthropogenic activities

Mining resources

Prior 4400 BC

till 1500 AD after 1800 AD

Zero Embodied Carbon materials Medium Embodied carbon materials High Embodied Carbon materials

Global consumption of construction materials: > 60 billion t /annum Per capita consumption: 8 t/annum (~6.5 t is aggregates)

Reddy BVV, SCMT5, 2019

Material resources

Exhaustible: Soil, Stone, Sand, Minerals & chemicals.... Renewable: Biomass - grasses, bamboo, wood… grown Recyclable: Solid wastes - Industrial & mine ..

Sustainability?

There are many definitions for sustainability

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Definition of sustainable development

Kumarappa (1945) “Economy of permanency” Brundtland report (1987) Sustainable society:  Manages its economic growth without causing irreparable damage to environment  Satisfies peoples’ needs without jeopardizing prospects of future generations Sustainable development:  Meeting the needs of the present without compromising ability of future generations to meet their own needs

Prime focus in both these definitions is:

• Sustainable extraction of resources from the planet earth
• Without causing irreparable damage to the environment

… sustainability – renewable/regenerate

Pillars of Sustainability

• Socio…
• Economic..
• Environ..

Demand for Material resources Mined resources

Sustainability ?????

Need for renewable resources

The planet hosts several living organisms

• Human societies occupy ~2% of the planet’s surface

area but consume 75% of the planet’s resources (O’Meara 1999)

What is Green (construction)?

…green is about decarbonization!

refers to the changing relative amounts of carbon and hydrogen in the fuels burnt to generate energy ….....(T. Bradford, 2006)

… about emission reduction

Type of fuel Carbon Hydrogen Firewood Coal Oil Natural gas Hydrogen 10 2 1 1 1 1 2 4 1

Built Habitat/Environment

Consume

• Energy
• Material resources

Generate

• Wastes
• Emissions

45 50 60 20 40 60 80 100 120

Energy use Global water consumption Global raw material consumption

%

[Willmott Dixon Group 2010]

By 2025, Buildings worldwide will be the largest consumers of global energy - greater than the transportation and industry sectors combined.

Agriculture 7% Industry 44% Transport 18% Residential & commercial 14% Others [PERCENTAGE ] [CATEGORY NAME] [PERCENTAGE]

India (2012)

[Teddy 2013]

Energy in Buildings

Buildings

Energy for Materials & Construction

Energy for maintenance

Embodied Energy Operational Energy

Operational Energy Embodied Energy

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Raw material extraction Building material production Construction Operation, maintenance, repair & refurbishments Demolition & Disposal Initial Embodied Energy Recurring Embodied Energy Operational Energy Demolition Energy Embodied Energy

• f building materials

& construction Durability of material Thermal performance

• f materials/system

Building Life Cycle Life Cycle Energy

Life Cycle Energy (LCE) of a building

Attributes of building material

Praseeda et al. 2014, E&B, 2015

Embodied Energy (EE) – System Boundaries

[Dixit et al. 2010] 13

Methods for Embodied Energy Analysis

• Process analysis
• Input – Output analysis
• Hybrid methods [Menzies et al. 2008, Treloar et al. 2000]

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Embodied Energy (EE) value depends upon

• System boundary considered
• Method of analysis

EE is not a unique value – it is a range

Process flow chart

Raw Meal

Limestone Other raw materials Raw Mill Preheater Kiln Clinker storage Cement Mill Cement storage Packing & Dispatch Gypsum Fly Ash or Slag Coal Mill Clinker cooling

Cement: Process of manufacture

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Embodied Energy in Cement

Cement ready to dispatch to site EE of cement = 2.376 MJ/kg Limestone Extraction Mixing and grinding of raw materials Clinker production Grinding of clinker Packing and storage Direct energy Indirect energy Stage 1 Embodied Energy Transportation energy Other raw materials Process Energy

0.032 MJ/kg 0.084 MJ/kg 2.26 MJ/kg

Praseeda et al. 2014, E&B, 2015

Embodied Energy in building materials

Type of material

• Sp. energy consumption

(MJ per kg) Cement Lime Lime-pozzolana Steel Aluminum Glass 3.00 - 4.00 (2.38 – 3.72) 4.75 – 5.75 2.00 – 2.50 42.0 (30) 236.8 (100 - 140) 25.8 (10 – 15) Burnt brick Hollow con. Block Vitrified floor tile 1 – 2.5 (1.2 – 4.05) 0.60 – 0.75 5.5 – 6.5 (10.63)

Red colour highlighted – Praseeda et al. E&B 2015

Embodied Energy of burnt clay brick

Types of kiln EE (MJ/kg) 1 Clamps 1.7 – 2.9 2 Intermittent type 1.88 3 BTKs 1.20 – 4.05 4 CBRI improved BTK 1.51 5 Hoffmanns kiln 2.94 6 Downdraught kiln 3.36 – 3.48 7 VSBK 1.20

EE of burnt clay brick: 1.20 – 4.05 MJ/kg

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1 2 3 4 5 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Embodied Energy

• f Brick (MJ/kg)

Praseeda et al. 2014, E&B, 2015

Sl. No. Climatic zone Mean monthly temperature (°C) Relative Humidity (RH) Regions 1 Hot and Dry Above 30 Below 55% Western & central part 2 Warm and Humid Above 30 Above 55% Coastal regions Between 25 - 30 Above 75% 3 Temperate (Moderate) Between 25 - 30 Below 75% Pune, Bangalore 4 Cold Below 25 For any RH value Northern parts of India 5 Composite Six months or more do not fall within any of the above categories New Delhi, Kanpur, Allahabad etc.

Embodied and operational energy in buildings

43 residential buildings in 4 climatic zones (27 rural dwellings & 16 urban dwellings) Designated as RD1 – RD27 UD1 – UD16

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Embodied energy in rural and urban dwellings EE of dwellings with natural materials is an order of magnitude lower than those with conventional brick-concrete

0.00 2.00 4.00 6.00 8.00 10.00 12.00

RD4 RD8 RD14 RD6 RD23 RD3 RD15 RD9 RD26 RD22 RD27 RD2 RD21 RD17 RD1 RD24 RD19 RD18 RD7 RD20 RD13 RD16 RD5 RD25 RD11 RD12 RD10 UD2 UD4 UD1 UD16 UD5 UD6 UD11 UD8 UD7 UD15 UD10 UD9 UD12 UD3 UD13 UD14 1 2 3 4 5 6 7 8 9

Embodied Energy (GJ/m2)

Monolithic RC walls

RC frame burnt clay brick masonry

load bearing burnt clay brick Rural dwellings with natural and conventional materials

Source: Praseeda et al. E&B, 2016

Embodied energy = 11 GJ/m2

Monolithic RC walls Load bearing brick masonry RC frame burnt brick masonry

EE = 4 – 6 GJ/m2 EE = 2.5 – 3.5 GJ/m2

Life Cycle Energy (LCE) in rural dwellings

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

RD1 RD2 RD3 RD4 RD5 RD6 RD7 RD8 RD9 RD11 RD12 RD13 RD14 RD15 RD16 RD17 RD18 RD19 RD20 RD21 RD22 RD23 RD24 RD25 RD26 RD27 Composite climate Warm & Humid climate Moderate climate Cold climate Life Cycle Energy (GJ/m2)

OE for 50 yrs EE

EE represents 0.21 to 68% of LCE in rural dwellings

Source: Praseeda et al. E&B, 2016

Life Cycle Energy (LCE) in urban dwellings

2 4 6 8 10 12 14 UD1 UD3 UD4 UD5 UD6 UD7 UD8 UD9 UD10 UD11 UD15 Composite Warm & Humid climate Moderate Cold

Life Cycle Energy (GJ/m2)

OE for 50 yrs EE EE represents 10 to 80% of LCE in urban dwellings

Source: Praseeda et al. E&B, 2016

Embodied vs Operational Energy

Urban dwellings from warm – humid and moderate climate zones

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1 2 3 4

5 10 15 20 25 30 35 40 45 50 Energy (GJ/m2/yr) Years EE (UD9) OE (UD9) EE (UD10) OE (UD10) EE (UD11) OE(UD11)

EE < OE EE > OE

Depends on

• Climate
• Conditioning type
• Envelope/materials

Source: Praseeda et al. E&B, 2016

Current rating systems

Attempt to address………

• Site planning, location & linkages
• Design, materials & construction
• Water & waste management
• Awareness & education
• Healthy living conditions
• Energy consumption, generation…
• Indoor environment quality, space conditioning…

Parameter Weightage LEED-USA BREEAM - UK GRIHA-India Materials, and construction methods 6 – 9% 13.5% 10% Energy

(consumption/generation, Indoor environment quality, space conditioning)

57% 39% 50%

Current rating systems

Attempt to link the concept of Green buildings to Sustainable Construction Energy conservation & pollution reduction

Too much emphasis on

Little or less emphasis on:

• Conservation of dwindling basic material resources
• Environmental damage due to indiscriminate mining of materials

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Sustainable habitat

Materials

Energy

Share of sustainability parameters in built habitat

Green Buildings address only

• Part of the

sustainability issues

Reddy BVV, SCMT5, 2019

Major issues Managing material resources Minimising pollution – Energy

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Sustainable habitat

Thank you

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Summary

• Consumption of construction material is

alarming: 8 t (6.5 t aggregates) /capita/annum

• Sustainable constructions: should address both

the issues on energy & material resources

• EE: not a unique value – it is a range & dynamic

EE < OE EE > OE

Details 30 - Storey concrete frame 2 - Storey brick wall Total weight (t) 1,66,944 550 Built up area (m2) 92,903 251 Weight (t/m2) 1.79 2.19 Embodied energy (GJ/m2) 4.28 2.40

Weight & Embodied Energy of Building

Masonry 7.40% Concrete 81.78%

Metal cladding 0.01%

Ceramic 1.22% Glass 1.17%

Plastering 3.32%

Steel 5.10%

Ceramic 1.94% Glass 0.10% Granite slab 0.60% Concrete 37% Stone Masonry 22.60% Brick Masonry 29.07% Steel 0.91% Timber 0.42% Plaster 6.94%

Distribution of mass

30 – Storey Building 2 – Storey Building

• Judicious use of material resources
• Use natural materials or effect changes with minimum

energy expenditure – low carbon materials

• Reduce & recycle – think end of life utilisation
• Great need to use biomass based renewable materials
• Utilise solid wastes for construction products

Possible options for addressing issues on sustainable construction materials

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