e
Output
70
%
Electricity
Consumption
In 2004, more than 3,700 Billion kWh of electricity
were generated in the U.S.*
Annual growth rate of 1.5%*
[USGBC 2007]
*
[Annual energy outlook, US DOE 2007] © 2007 Alcan Inc.
Slide 4
Wiring A building component that influences
energy efficiency not yet considered All buildings require wiring system and cable Designers, installers and regulators are familiar with
National Codes and Standards that provide installation
and performance requirements for electrical wire and
cable products used in feeder circuits There is ample awareness about the material and
installation costs for baseline designs. However, in todays environmentally conscious
environment there are no requirements that prescribe
the use of Life Cycle considerations for wiring methods. © 2007 Alcan Inc.
Slide 5
The importance of wiring on the overall energy
consumption of buildings US Annual energy Outlook 2007 [US DOE 2007]
Total electrical energy sold: 3700 Billion kWh (2004)
This energy ultimately flows through a feeder circuit and then through a
branch circuit before reaching the consumption point Requirements of the US National Electrical Codes Energy losses
Up to 5% losses permitted in feeder and branch circuits
Range of 1.25 5% (the circuits are not always used at maximum capacity,
therefore the losses are estimated to be lower than the percentage of
permitted losses) Total energy Losses
Feeder and branch circuits:
46 - 185 Bill. kWh per year.
Losses equivalent to power produced by 10 to 40 power stations of 500 MW. Greenhouse gas emissions
Based on US grid mix 0.78 kg CO2 eq/kwh:
36 144 Mill. t CO2 eq
. © 2007 Alcan Inc.
Slide 6
LCA to assess different wiring systems For this study the ISO 14040 compliant Modular LCA
approach was employed
This corresponds to a cradle to cradle approach
recovered material has no footprint and only the material which is
not recovered contributes to the product footprint. Following indicators have been calculated:
Primary Energy [MJ]: Total sum of consumption of non-renewable
primary energy resources
GHG (kg CO2 e): Greenhouse gas potential, expressed in CO2
equivalents for the assessed life cycles
Ecoindicator99 minus (points):
An indicator, which summarizes toxicity, ozone depleting,
acidifying, and other environmental impacts
Waste Indicator [kg MSW e]: Total waste generated for the
assessed life cycles, expressed in municipal solid waste (MSW)
equivalents
Water Consumption [kg]: Total water consumption for the
assessed life cycles © 2007 Alcan Inc.
Slide 7
Scope and goal of LCA A comparison has been performed for different products
Case 1: Optimized use phase (energy losses)
-
Cable material: Aluminium,
-
Two different cable design
Case 2: Same use phase characteristics
-
Two different cables materials: Aluminium and Cooper Included in analysis:
Only the phases which have distinct footprints
-
Raw material production of all materials
-
End-of-life phase of all the materials.
-
Identical recovery rates for both aluminum and copper cables
-
Reflecting the reality of recycling activities in North America
-
Based on estimations given by the US EPA and detailed research by
Five Winds Not included in the study are:
The fabrication processes of cable insulation and assemblies, assumption
similar for all assessed products
Transport processes to the cable fabrication plants and from there to the
final building, very minor importance, similar for all products © 2007 Alcan Inc.
Slide 8
Case 1: Optimization of the Use Phase Instead of building the wiring system according to
national code and standard requirements, the cable
design could be adapted to optimize the footprint of the
use phase:
Reduction of use phase energy losses Two different aluminum wiring design have been
compared on the overall life cycle performance
Product description
-
Functional unit: 250 feet cable, 400 Amp
-
Baseline design: Aluminum Cable, STABILOY MC
-
Optimized design: Aluminum Cable, Upsized
STABILOY MC 30 years use phase for the cable systems assumed © 2007 Alcan Inc.
Slide 9
By Optimizing the Wiring Methods significant life
cycle saving can be achieved in energy and GHG For the optimized design the absolute savings over a baseline
design are (250 feet, 400 Amp):
Non-renewable primary energy:
-
1200 GJ to 4800 GJ (life time of 30 years)
-
40 GJ to 160 GJ (annually)
GHG:
-
81 to 324 t (life time of 30 years)
-
2700 kg to 10800 kg (annually) For comparison:
By replacing a midsize refrigerator with a more energy
efficient one, the yearly GHG savings are in the range of
1000 kg © 2007 Alcan Inc.
Slide 10
Use Phase much more important than all other
Life Cycle Phases In average per pound of aluminum used for an upsized
wiring system the savings are:
Non-renewable primary energy savings of about: 1000 -
4000 MJ
Greenhouse gas savings: 70 - 270 kg CO2eq
This is compared to the baseline system, with 1 lb Al in the
baseline being replaced by 1.6 lb in the upsized system. In average to produce a pound of primary aluminum the
greenhouse gas impacts are:
5 kg CO2eq per lb of aluminum
To produce a lb of aluminum from recycled aluminum only
5% of the GHG are produced compared to primary
The recycling rate of cable in the US is > 95% © 2007 Alcan Inc.
Slide 11
What means Use Phase Optimization on a
US Macro Level The amount of aluminum used in 2006 for building wire
and cable, according to the US Census Bureau were:
132,620,000 lb If 1% of the feeder and branch circuits build today in
aluminum in the US would be upsized, the resulting
savings would be:
Primary energy:
-
14 - 56 Mill GJ (life time of 30 years)
-
0.47 1.87 Mill GJ (annually)
GHG:
-
0.94 3.8 Mill t CO2 eq (life time of 30 years)
-
31,400 to 125,500 t CO2 eq (annually) © 2007 Alcan Inc.
Slide 12
Case 2: Same Use Phase - Different Materials For building wire system essentially two wiring material
are used, Copper 85% and Aluminium 15% In case 2 the life cycle impacts of the two wiring
material was assessed, both products comply with
national codes and standards:
Product compared
-
Aluminum cable: STABILOY MC cable
-
Copper cable: THHN Conductors (PVC Insulation
& Nylon Jacket)
Same use phase requirements, therefore use phase
not included
Different cable ratings between 200 - 4000 Amp © 2007 Alcan Inc.
Slide 13
LCA shows the difference of material choices
0.0%
20.0%
40.0%
60.0%
80.0%
100.0%
Ecoindicator 95
minus
Ecoindicator 99
minus
Waste Indicator
Water consumption
GHG
Prim. Energy
Aluminum Stabiloy MC cable
Copper THHN conductors
Average difference in impacts for cable ratings between 200 4000 Amp
Assumption : 90% recycling rate for metals, all other materials landfilled © 2007 Alcan Inc.
Slide 14
Energy savings for 250 feet cable and different
Amp
0
20000
40000
60000
80000
100000
120000
140000
160000
200
400
800
1000
1200
1600
2000
2500
3000
4000
Cable rating
N
o
n-
r
e
ne
w
a
bl
e
pr
i
m
a
r
y

e
ne
r
gy
[
M
J
]
Average savings per lb of aluminum introduced
into the wiring system: 15 MJ © 2007 Alcan Inc.
Slide 15
Greenhouse gas savings for 250 feet cable of
different Amp
0
2000
4000
6000
8000
10000
12000
200
400
800
1000
1200
1600
2000
2500
3000
4000
Cable rating
kg
C
O
2 eq
u
i
v.
Average savings per lb of aluminum introduced
into the wiring system: 1.1 kg CO2eq © 2007 Alcan Inc.
Slide 16
Sustainability of wiring methods social and
economic considerations have to be added Social considerations
Production and end-of life phases
-
Dependent on specific company, not on general
product
Use phase
-
Same safety standards have to be fulfilled for all
products Economic considerations:
Copper price per lb: 3 times higher then aluminum
price
2.1 lb copper needed for 1 lb of aluminum
Upsizing with aluminum lower cost than standard
copper cable © 2007 Alcan Inc.
Slide 17
Conclusions There is a tremendous interest in the society to make
buildings more energy efficient. The results of the studies demonstrate that wiring
methods can have a significant contribution. The existing technical national codes and standards up
till now do not include broader sustainability
considerations. It is important to raise the awareness of assessing
building products by using
life cycle thinking and
approaches
to be able to capture all potential energy
efficiency improvements potential. © 2007 Alcan Inc.
Slide 18
.