embodied energy lecture 702-865 2009

7/31/2019 Embodied Energy Lecture 702-865 2009

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Embodied Energyin a life cycle context

Dr Robert Crawford

Faculty of Architecture, Building and PlanningThe University of Melbourne

www.ch2.com.au

Environmental SystemsSemester 2, 2009

theoretical overview & case studiesin the built environment

building environmental loadings and energy use

what is embodied energy?

the embodied energy context

strategies for reducing embodied energy

case studies and example calculation

why take a life cycle approach?

what is life cycle energy?

strategies for optimising life cycle embodied energy

life cycle energy examples

assessment tools

overview

Environmental Systems, September 2009

32% of world resources

12% of water consumption

40% of waste to landfill

40% of energy consumption

40% of air and GHG emissions

(OECD 2003)

building environmental loadings

Images source: Googleimages, 2008 Environmental Systems, September 2009

http://members.cox.net/slsturgi3/population_growth.gif

resource demand driven by population growth

20096.8 billion


http://www.peakoil.org.au/charts/world.energy.consumption.1965-2007.gif

trend in world energy consumption


6%

9%

15%

16%

21%

33% Cooking and Hot water

Equipment

Lighting

Ventilation

Cooling

Heating

commercial building operational energy use

Source: Australian CommercialBuilding SectorGreenhouse Gas Emissions 19902010, AGO 1999



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building operational efficiency

improvements to building resource consumption have

typically focused on the operational phase, particularlydirect fossil fuel and water consumption

efficiency measures are reducing household energy andwater consumption, not per capita


operational energy efficiency strategies

planning and design

orientation

insulation

natural ventilation

thermal mass

shading

solar (electric and thermal)

wind

geothermal

passive

active

building life cycle


Maintenance

energy

(1%)

Embodied energy

(initial)

(43%)

Operational

energy

(45%)

Renovation/

refurbishment

(9%)

Construction

energy

(2%)

building life cycle energy consumption


The energy required by all of the activities associatedwith a production process and the share of energy used

in making equipment and other supporting functions(i.e. direct and indirect).

(after Treloar, 1994).

embodied energy


raw material extraction and processing

material/component manufacture

transport

construction/manufacture

banking

insurance

marketing

communication services

accommodation

etcetera

what does embodied energy include?



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stage 0 stage 1 ...

upstream

stage 2 stage

direct energy indirect energy

direct

energy

direct

energy

direct

energy

direct

energy

Construction productsproductsproducts

Downstreamincludes building use - not as complex as upstream

embodied energy

Source:Crawford,2005


process analysis

- based on physical quantities

- up to 90% incomplete

input-output analysis

- based on financial quantities (GJ energy / $1 product)

- systemically complete, unreliable

hybrid analysis

- combines process and input-output analysis

- systemically complete and more reliable

quantifying embodied resource requirements and impacts


Construction

construction system boundary


the supply chain is complex

Slide removed from handouts

Commercial buildings:

steel 9.3%

concrete 8.7%

road transport 3%

Residential buildings:

ceramic products 11.3%

concrete 9.3%

metal products 8.2%

where is most energy used?

Initial findings, based on input-output data:

- Residential buildings: 10.6 GJ/$1000

- C ommercial buildings: 9.98 GJ/$1000


most comprehensive available

developed by the late A/Prof Graham Treloar (mid 90s)

based on:

- energy intensities of specific construction materials (using the mostdetailed database currently available in Australia)

(GJ of energy per m3, m2 or t of material)

- national average statistical data (input-output - includes capitalinputs, imports, minor goods and services)

hybrid embodied energy model



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calculating initial embodied energy

1) specify materials (types, thicknesses and quantities)

2) multiply individual material quantities by respective material

energy intensities (GJ of energy per m3, m2 or t of material)

3) add energy for minor goods and services using input-output data


3-storey commercial office building

location: Melbourne

floor area: 11 600m2 GFA

Embodied energy:

25.8GJ/m2 GFA (300 000GJ)

46 years of operational energy

(0.558GJ/m2/year)

case study Toyota Head Office

source: www.toyota.com.au


0 2 4 6 8 10

Structure group

Finishes

Substructure

Roof

Windows

Direct energy

Other items

GJ/m2

other items 31%

structure group 22%

windows 1 3%

direct energy 5.3%

embodied energy, by element


0 2 4 6 8 10

Steel

Concrete

Other metals

Ceramics

Carpet

Glass

Plasterboard

Plastic

Paint

Timber products

Direct energy

Other items

GJ/m2

embodied energy, by material

other items 31%

steel 3 0%

glass 1 3%

concrete 6%


building embodied energy equates to:

- 20 to 50 years of operational energy

- up to 50% of lifetime energy use (50 year building life)

typical embodied energy:

- 10 to 20 GJ/m2 GFA residential

- 20 to 30 GJ/m2 GFA commercial

energy embodied in buildings


Residential buildings:

direct (on-site) energy -


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increasingly significant due to improved operational efficiencies

value of resources increasing

prices will rise, supply may be restricted

energy water resources waste disposal

potential for future carbon taxes/trading

demand needs to be managed for sustainable development

embodied resources


production of energy releases greenhouse gas emissions

emission of GHGscontributes to global warming

on average, 60kg CO2 emissions released per GJ of energy produced

equates to 240t CO2 to construct an average house

over 200 times volume of average house

4.8 million balloons

environmental impacts from embodied energy


Up to 90% of impacts are locked in

at the design stage


Reduce use of materials

- quantity (eg. reduce building size)

- particularly those with high EE

- use alternative materials with lower EE

- rationalise design

- avoid redundant structure and facilities

reducing embodied energy reduce


0

10

20

30

40

50

60

70

80

90

100

1950 1960 1970 1980 1990 2000 2008

Floorareaperperson(m

2)

Floor area per person has almost quadrupled

reducing embodied energy reduce


Reuse materials in place

design for adaptive use

structural integrity issues

fit for future use?

reusing existing structure can save up to 50% of total building EE

reusing materials can save up to 95% of EE of new materials

Reuse materials from elsewhere

this site or another project

design for disassembly

time and cost to make good

can save up to 90% of EE of new materials

(depends on transport and extent of making-good)

energy required for transport, installation

reducing embodied energy reuse



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Use/specify recycled materials


EE saving depends on transport, re-processing energy

Use/specify materials with recycled content

e.g. concrete with flyash / recycled aggregate

Use/specify renewable materials

t imb er

b amboo

biomass waste (eg. bio-plastics)

reducing embodied energy recycle


prefabricated modular steel v concrete

Source: Fender Katsalidis Architects


prefabricated modular steel v concrete


0

10000

20000

30000

40000

50000

60000

Steel Concrete

Construction system

Embodiedenergy(GJ)

Staircase

Floor tilling

Doors & windows

Roof

Internal walls

Ceiling

External cladding

Floor panels

External walls

Columns & beams

benefits from material reuse

81% energy saving from reuse of steel

influenced by reusability (disassembly)


0

10

20

30

40

50

60

70

80

90

100

Volume Weight Embodied Energy

Percentage

Steel Concrete

Deakin University,

Waterfront Campus,

McGlashan & Everist,

1995

Church conversion, Glenlyon

Multiplicity 2004


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Melbourne GPO, 2001

Melbourne GPO

Williams Boag, 2004

embodied energy calculations

Example

Example: concrete floor


Element description: concrete floor slab, carpeted

Functional Unit: one square metre of floor

Materials: concrete 32MPasteel reinforcementnylon carpet

example: concrete floor


Embodied Energy Calculation:

* equivalent to fuel needed to travel by car for 818km

Assumptions:

slab 150mm thick

100kg steel per m3 concrete

example: concrete floor


embodied energy intensities




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Potential limitations

assessment method error tolerances (+/- 20%) = 2.2GJ 3.3GJ

Evaluate implications (substitute materials, details)

other floor materials e.g. timber

other floor covering materials e.g. tiles

Opportunities for optimising EE in this application

using reused/recycled materials (concrete)

using recyclable materials

material durability & expected life

example one: concrete floor


Brick veneer Weatherboard

embodied energy of building assemblies

V


initial embodied energy

important to assess life cycleimpacts

building life cycle


ensures the multiple environmental and resource issuesacross the entire life cycle of the product are identified

helps to ensure reducing waste at one point does notsimply create more waste at another point in the life cycle

a life cycle approach



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embodied energy (initial and recurring)

operational energy

maintenance energy

end of life energy (reuse, recycling, disposal)

life cycle energy


Embodied Energy

Building A appears the best choice

Life Cycle Energy

Building B consumes less energyoverall

Building A Building BBuilding A Building B

GJ GJRefurbish

Operation

EmbodiedEnergy

EmbodiedEnergy

a life cycle approach


commercial building life cycle energy

< quantum leaps

indicate periods

of refurbishment

^ gradient gives

operational

energy< initial

construction

embodied energy

0

5

10

15

20

25

30

35

0 10 20 30 40

Time (years)

Lifec

ycleenergy(GJ/m2)

building life cycle energy

(GJ/m2)


reduce non-renewable resource use

design for energy efficiency

specify low-impact materials

design for quality and durability

design for reuse and recyclability

reducing life cycle energy


Lowering initial EE is not always ideal

Consider the life cycle implications of this on:

recurring EE (replacement)

maintenance energy

operating energy

Life cycle EE is affected by:

material durability

anticipated life (replacement cycle)

a life cycle approach to embodied energy



select materials for durability, long life and recyclability

look to the future - use/specify renewable materials

t imb er

b amboo

bio-plastics

most importantly consider life cycle impacts

optimising life cycle embodied energy



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life cycle view =maximum benefits



assess building componentsand systems

often, efficiency and design improvements that reduce operationalresource requirements or impacts come at the expense of greaterembodied or life cycle requirements or impacts

e.g. double / triple glazing reduces building operational energyrequirements (compared to SG)

BUT, increases embodied resource requirements(materials, energy, water and associated impacts)

key question does it provide a net life cycle benefit?

crucial to assess/consider life cycle environmental impacts toensure net environmental benefits are achieved

ensuring environmental outcomes are not compromised


Brick veneer Weatherboard

life cycle energy of building assemblies

V


calculating life cycle embodied energy

1) specify material useful life (maintenance or replacement period)


calculating life cycle embodied energy

2) calculate combined initial and recurring embodied energy



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life cycle embodied energy life cycle embodied energy of floor assemblies


0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

GJ/m2

Elevated timber

floor

110mm concrete

slab on ground

205mm Hollow

Core precast

flooring

100mm elevated

concrete slab,

permanent

formwork

Recurrent embodied energy

Initial embodied energy

life cycle energy of floor assemblies

quantum leaps indicatemaintenance or materialreplacement

gradientrepresentsoperationalenergy

initial embodied energy


0

1

23

4

5

6

7

8

9

10

0 5 10 15 20 25 30 35 40 45 50

Years

GJ

Elevated timber floor Concrete slab on ground

predicted total cooling energy saving: 280 GJ/year (83%)

PCM (in s/steel balls) contribute to some of this

however, 23 t of s/steel = 10,190 GJ embodied energy

36 years energy payback

CH2 cooling system embodied impacts

www.ch2.com.au

0

200

400

600

800

1000

1200

1400

1600

1800

2000

EE

(GJ)

2 4 6 8 10 12 14 16 18 20

Years

Life-cycleenergy(GJ)

EHWS

GHWS

GIHWS

SEHWS

SGHWS

life cycle energy of hot water systems


-60

-40

-20

-

20

40

60

0 2 4 6 8 10 12 14 16 18 20

Years

PrimaryEnergy(GJ)

BiPV c :Si BiPV c :Si HRU BiPV a :Si HRU

life cycle energy of photovoltaic systems



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0

10

20

30

40

50

60

70

80

90

100

High R is e 7 -Star Ho us e Sub urban

Apartment

2008 House

Energy

(GJ

percapita)

Operational Energy

Embodied Energy

Travel Energy

Total Energy

annualised residential life cycle energy


-200,000

200,000

600,000

1,000,000

1,400,000

1,800,000

2,200,000

EE 5 10 15 20Life-CycleEnergyOutput(G

J)

850 kW wind turbine

3.0 MW wind turbine

life cycle energy of wind turbines


0

500,000

1,000,000

1,500,000

2,000,000

2,500,000

3,000,000

3,500,000

4,000,000

4,500,000

1 4 7 10 1 3 16 1 9 22 25 28 3 1 34 3 7 40

Time (years)

Lifecycleenergy(GJ)

Vehicle operationalVehicle manu. & maint.CRC - road typesPCFDACompDSAG

DSABACB

direct and indirect energy of road construction and use


direct and indirect CO2 emissions of pipe systems


0.0

0.3

0.6

0.9

1.2

DICL China

DN600

DICL Aust.

DN600

DICL China

DN450

DICL Aust.

DN450

tCO2-epermo

fpipe

indirect emissions

direct emissions

raw mat. trans.

pipe transport

cement lining

embodied CO2

emissions of concrete railway sleepers


0 50 100 150

Sleeper

Tendons

Fastenings

Direct emissions

Other items

t CO2 -e per km of track

process values

input-output values

0

500

1000

1500

2000

2500

3000

3500

4000

0 10 20 30 40 50 60 70 80 90 100

Years

tCO2-eperkm

Concrete (C4)

Timber (T4)

Timber 50 (T8)

Timber 96 (T12)

sleeper replacement

decay emissions

life cycle CO2

emissions of railway sleepers



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building embodied water equates to:

- 20-80 years of operational water

- up to 60% of lifetime water use (50 year building life)

typical embodied water:

- 10-20 kL/m2 GFA residential (4-8 times building volume)

- 20-30 kL/m2 GFA commercial

water embodied in buildings


LISA

SimaPro

Ecotect

LCADesign

GaBi

life cycle assessment tools


LISA


Project

details andparameters


LISA

Specifyconstruction

elements


LISA

Specify

fit outelements


LISA


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Specify

appliances


LISA

Specify

usage

details


LISA

Specify

maintenance

requirements


LISA

Specify

materialre-use


LISA

Specify

material

transport


LISA

inputs andoutputs by

material

quantity


LISA


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Project

quantities


LISA

Impact

assessmentby life-cycle

stage


LISA

Range of

impact

categories


LISA

Breakdown

of life-cycle

stage


LISA


SimaPro

Specify

assembliesor elements


SimaPro


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Select &quantify

materials


SimaPro

Select

materials/

processes


SimaPro

Material

inputs &

outputs


SimaPro

assessment

by impactcategory


SimaPro

Impacts byproduct

stage


SimaPro

Comparison

of twoproducts


SimaPro


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Ecotect


consider source of materials

maximise value of resources minimise wastage

reuse and/or recycle existing materials

maximise opportunities for reuse, through design

consider durability of recycled/reused materials

consider maintenance and replacement requirements

consider life cycle resource requirements/impacts

consider on-going implications of design decisions

summary


embodied energy lecture 702-865 2009

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