Upload
others
View
7
Download
0
Embed Size (px)
Citation preview
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
3
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
6
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 0
1 1 2 4 1
Built Habitat/Environment
Consume •Energy •Material resources
Generate •Wastes •Emissions
45 50 60
0
20
40
60
80
100
120
Energy use Global waterconsumption
Global raw materialconsumption
%
[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
11
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
of building materials
& construction
Durability of material
Thermal performance
of 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]
14
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
15
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
Dir
ect en
erg
y
Indir
ect
energ
y
Sta
ge 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
18
0
1
2
3
4
51
2
3
4
5
6
7
8
9
10
11
12
13
14
Embodied Energyof 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
19
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
RD
4
RD
8
RD
14
RD
6
RD
23
RD
3
RD
15
RD
9
RD
26
RD
22
RD
27
RD
2
RD
21
RD
17
RD
1
RD
24
RD
19
RD
18
RD
7
RD
20
RD
13
RD
16
RD
5
RD
25
RD
11
RD
12
RD
10
UD
2
UD
4
UD
1
UD
16
UD
5
UD
6
UD
11
UD
8
UD
7
UD
15
UD
10
UD
9
UD
12
UD
3
UD
13
UD
14
1 2 3 4 5 6 7 8 9
Em
bo
die
d E
ne
rgy (
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
RD
1
RD
2
RD
3
RD
4
RD
5
RD
6
RD
7
RD
8
RD
9
RD
11
RD
12
RD
13
RD
14
RD
15
RD
16
RD
17
RD
18
RD
19
RD
20
RD
21
RD
22
RD
23
RD
24
RD
25
RD
26
RD
27
Composite climate Warm & Humid climate Moderateclimate
Coldclimate
Lif
e C
ycle
En
erg
y (
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
0
2
4
6
8
10
12
14
UD1 UD3 UD4 UD5 UD6 UD7 UD8 UD9 UD10 UD11 UD15
Composite Warm & Humid climateModerateCold
Lif
e C
ycle
En
erg
y (
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
24
0
1
2
3
4
0 5 10 15 20 25 30 35 40 45 50
En
erg
y (
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 26
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
28
Sustainable habitat
Thank you 29
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
32