Energy Efficiency @ Infosys
The context…
1,30,000 employees
28 million sq.ft.
• Total built-up space of Infosys, India at the end of 2010-11
26.5 crore units
• Annual electricity consumption @ Infosys, India in 2010-11
10 lakh units
• Consumption per working day @ Infosys, India in 2010-11
3
Our Carbon Footprint
Misc.
(13 million units)
5%
Mobility
Air conditioning
UPS
34%
(106 million
units)
40%
Electricity
66%
(106 million
units)
40%
Lighting / Raw
power
(40 million units)
15%
Electricity
Employee
commute
24%
Business
travel
76%
Mobility
4
Existing buildings
5
Measure, Monitor & Control
• You cannot control what you cannot measure !
• Installed over 1500 energy meters starting from 2008 to measure energy
consumption of various energy consumption categories
− Building incoming feeder
− Chiller plant main panel, and further sub metering
− Lighting/raw power panel
• This was the starting point for energy efficiency measures in existing
buildings
6
Monitoring energy consumption
7
8
Initiated Audits
9
Actual consumptions versus
design assumptions
10
10% overall Savings
11
12
Energy consumption profile on a weekday
13
Energy consumption profile on a weekend
14
Energy efficiency in HVAC
• Energy audits were initiated
• Consolidated on the operating hours across locations
• Defined operating patterns of equipments
• Replacement of old equipments with poor efficiencies
• Chiller plant re-engineering to get them to highest efficiency standards
• Daily energy reports to the facility managers
15
Question all the assumptions
16
Energy Efficiency in HVAC
Chiller plant re-engineering – a case study
Existing Chiller plant details :
Re-engineered Chiller plant details :
Chillers:
4 X 250 TR = 1000TR
Chillers:
4 X 250 TR = 1000TR
Auxiliary Connected load : 298 KW
Primary Pumps : 5 No’s
Secondary Pumps : 4 no’s
Condenser Pumps : 5 No’s
CT fans : 4 no’s
Auxiliary Connected load : 88 KW
Primary Pumps : 4 No’s
Condenser Pumps : 4 No’s
CT fans with VFD : 4 no’s
17
Energy Efficiency in HVAC
Location
Existing
chillers
Current efficiency
Proposed
replacement
Proposed
efficiency
Pune
175 TR x 2
175 TR x 2
0.8 kW/TR
0.8 kW/TR
200 TR x 1
200 TR x 1
0.53 kW/TR
0.53 kW/TR
Chennai
450 TR x 1
400 TR x 2
350 TR x 1
0.7 kW/TR
450 TR x 1
0.58 kW/TR
Mangalore
250 TR x 3
0.8 kW/TR
250 TR x 1
0.58 kW/TR
Bangalore
150 TR x 1
100 TR x 1
0.85 kW/TR
180 TR x 1
0.53 kW/TR
18
Energy Efficiency in HVAC
Location
Re-engineering projects
Bangalore
Park 1, 2 , 3
Park 6
Hyderabad
Chennai
542
74
Phase 1
Pumps replacement and re-engineering completed
115
Phase 2
Pumps replacement and re-engineering completed
180
condenser pumps completed
96 AC units replaced.
90
77
GEC1
Re-engineering completed , pumps installation is completed & VFD
commission is in progress.
210
Shols
Shols
Condenser pumps completed
Chilled water pumps completed
Ph-2 ECC
Mangalore
Load Reduction in
KW
Park 1,2 & 3 re-engineering completed.
VPF conversion completed
Phase 2
Single unit
Mysore
Status
Nethra campus
ECC condenser pumps installation completed
54
199
178
ECC chilled water pumps installation completed
216
Chilled water pumps installation completed
130
Total Connected Load Reduction
19
2065
Energy Efficiency in Lighting
• Occupancy sensors in rest rooms, cabins
• LED lights in WCs (replacing CFL)
• LED street lights (replacing HPSV)
• Lighting energy savers on the panels
• Astronomical timers for street lighting
• LEDs for corridor lighting (replacing CFL)
20
Impact of Energy Efficiency Initiatives to the bottom line
Increased
by 18%
23%
improvement
Energy consumption for 2011-12 is estimated at 205 units/emp/month
21
New buildings – A new approach
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Integrated design approach
• Efficient building design
• Efficient lighting
• Efficient air conditioning
• Efficient control system for operation
• ECBC as the baseline
23
Day Lighting in Buildings: Trivandrum
Trivandrum SDB 1 building with high
performance glazing shaded
externally
Artificial lights are not required during daytime.
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8X saving in operations cost– Trivandrum SDB 1
Trivandrum SDB 1
Luminaire Used
Power (W)
No of Luminaires
Hours of operation
Cost of Power (INR)
Operational Cost per year
(INR)
Cost Saving (INR)
Old Standards
New Design
4x18W T8
4x14W T5
76
60
2010
1081
12
4
3.25
3.25
1,548,986
197,304
(per year)
Note: 260 working days considered per year.
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X multiple
Simulations for optimization
Day lighting
sensors
LED replacing
CFLs
300% improvement in Lighting design
2X reduction in the installed lighting load
~3X reduction in lighting energy consumption
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HVAC Design optimization process
Goal
To maximize energy efficiency in building HVAC system through
design interventions
Step 1
• Prevent heat coming into the building as much as possible
Step 2
• Design efficient system to maximize energy efficiency
Step 3
• Select high efficiency equipments to further maximize energy efficiency
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Heat loads – Heat Sources
1
Fresh air
Roof
Lights
1
24 0C
1
Glass
People
Equipment
35
0C
28
Walls
Building Envelope: Insulation
Wall (5X)
35 0C
Roof (13X)
24 0C
45 0C
RCC roof
22 Watts
24 0C
55 Watts
Plain Brick wall
35 0C
24 0C
35 0C
Insulated RCC roof
4.4 Watts
24 0C
Double brick wall with insulation
29
4 Watts
Building Envelope: High Performance glazing (5.8 X)
Solar
UV
Far
Red
FarInfra
Infrared
Near Infra
Near Red
Infrared
Visible
.25 .38
Thermal
.78
2.1
2.60
50 microns
Single glass
Spectrally selective double wall
glass with Argon filling
900 W
900 W
24 0C
35
24 0C
0C
810 W
360 W
90 W
540 W
35 0C
55 W
12 W
30
Case Study: Building in Mysore (1.8 X)
No additional cost
Sl.
No.
Case
Chiller capacity
required
(TR)
Annual energy
consumption (kWh)
Maximum electrical
load (kW)
1
Conventional building envelope
622
3,244,284
1,052
2
Efficient building envelope
530
3030908
968
3
Efficient lighting design
510
2713390
882
4
Efficient computers
486
2358776
778
5
Variable Air Volume system for AC
486
2080462
754
6
Heat Recovery Wheels for AC
400
2015430
662
7
Ultra high efficiency chiller
400
1992156
650
8
Efficient chilled water system design
400
1960898
640
9
High efficiency cooling tower
400
1946532
632
10
Lighting controls
400
1,775,706
600
31
Advanced Cooling Technologies
Water Vs Air as heat transfer medium
Specific heat of water
4.2 kJ/kg deg K
Density of water
1000 kg/m3
Specific heat of air
1.0 kJ/kg deg K
Density of air
1.25 kg/m3
Water can store 3,400 times more thermal energy per unit volume than air!
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66% energy savings: Alternative cooling strategies
•
•
•
•
•
•
Highly insulated building
Evaporative cooling
Heat recovery wheel/Free Cooling
Radiant cooling/Chilled beams
Building management software
Very efficient equipments
24 0C
35 0C
200
mm
150
mm
4.4
Watts
Outside
inside
Double brick wall with insulation
Radiant cooling pipes embedded in the slabs
33
Smart buildings – actual data
Design Vs Actual
Efficiencies
Design Vs
Actual
Efficiencies
Benchmarking
34
Smart buildings – actual data
35
>200% improvement in overall energy efficiency of new SDBs
Annual Energy Consumption in Units per SQM (Apr 2011 – Jan 2012)
250
231
219
203
Units per sqm
200
186
150
129
90
100
50
0
Hyderabad (old
campus)
Pune Ph-2
Chennai M-City
36
Mangalore Mangala
Trivandrum
Hyderabad (New
campus)
300% Improvement in air-conditioning design
•
Figures based on actual
measured data in
Hyderabad climate for
Apr 2011 – Feb 2012
•
3X improvement in
efficiency compared to
2007 design
•
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Radiant cooling at no
additional cost
Green Building Certifications
• LEED Platinum rating for BPO-1, Jaipur
• LEED Platinum rating for SDB-1, Trivandrum
• LEED Platinum rating for SDB-5, Mysore
• LEED Platinum rating for SDB-1, Hyderabad
• BEE 5-star rating for BPO-1, Pune
• All new buildings of Infosys since 2008 have been registered for Green
Building rating – LEED / GRIHA
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Redefining the standards
• Building envelope heat load not to exceed 1.0 W/sqft
• More than 75% of the office area to be naturally lit as per LEED standards
Breaking the barrier…………..
• > 550 sqft per TR of AC area
• < 0.4 W/sqft for lighting design
• < 0.5 kW/TR for chiller plant design
• < 3.5 W/sqft for electrical design
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Experiences / Conclusions
• Set unreasonable targets
• Efficient buildings do not cost more, but need a little effort at the right time. All
Infosys buildings exceed ECBC efficiency requirements.
• Good design = job half done !
• Question all assumptions and get the sizing right
• Select right sized efficient equipments and smart controls
• Measure, monitor……..Measure, monitor………..feedback….
• Seeing is believing……………Welcome to Infosys.
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Thank you
Guruprakash Sastry
Senior Manager – Green Initiatives | Infrastructure
Infosys Limited
Bangalore 560 100
Tel: +91 80 39148650
M: +91 97399 76191
Email: guruprakash_sastry@infosys.com