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Energy Efficiency @ Infosys
The context…
1,30,000 employees
• Total built-up space of Infosys, India at the end of 2010-11
28 million sq.ft.
• Annual electricity consumption @ Infosys, India in 2010-11
26.5 crore units
• Consumption per working day @ Infosys, India in 2010-11
10 lakh units
3
Our Carbon Footprint
Mobility 34%
Electricity66%
Air conditioning(106 million
units)40%
Lighting / Raw power
(40 million units)15%
UPS(106 million
units)40%
Misc.(13 million units)
5%
Employee commute
24%
Business travel76%
Electricity
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 :
Chillers:4 X 250 TR = 1000TR
Auxiliary Connected load : 298 KWPrimary Pumps : 5 No’s Secondary Pumps : 4 no’sCondenser Pumps : 5 No’sCT fans : 4 no’s
Re-engineered Chiller plant details :
Chillers:4 X 250 TR = 1000TR
Auxiliary Connected load : 88 KWPrimary Pumps : 4 No’s Condenser Pumps : 4 No’sCT fans with VFD : 4 no’s
17
Energy Efficiency in HVAC
Location Existing chillers
Current efficiency
Proposed replacement
Proposed efficiency
Pune 175 TR x 2175 TR x 2
0.8 kW/TR0.8 kW/TR
200 TR x 1200 TR x 1
0.53 kW/TR0.53 kW/TR
Chennai 450 TR x 1400 TR x 2350 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 1100 TR x 1
0.85 kW/TR 180 TR x 1 0.53 kW/TR
18
Energy Efficiency in HVAC
19
LocationRe-engineering
projectsStatus
Load Reduction in KW
BangalorePark 1, 2 , 3 Park 1,2 & 3 re-engineering completed. 542
Park 6 VPF conversion completed 74
Hyderabad
Phase 1 Pumps replacement and re-engineering completed 115
Phase 2 Pumps replacement and re-engineering completed 180
Phase 2 condenser pumps completed 90
Mysore
Single unit 96 AC units replaced. 77
GEC1Re-engineering completed , pumps installation is completed & VFD commission is in progress. 210
ChennaiShols Condenser pumps completed 54Shols Chilled water pumps completed 199
Ph-2 ECCECC condenser pumps installation completed 178
ECC chilled water pumps installation completed 216
Mangalore Nethra campus Chilled water pumps installation completed 130
Total Connected Load Reduction 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% improveme
nt
Energy consumption for 2011-12 is estimated at 205 units/emp/month
21
New buildings – A new approach
22
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
Artificial lights are not required during daytime.Trivandrum SDB 1 building with high performance glazing shaded externally
24
8X saving in operations cost– Trivandrum SDB 1
Trivandrum SDB 1
Old Standards New Design X multiple
Luminaire Used 4x18W T8 4x14W T5
Power (W) 76 60 1.27
No of Luminaires 2010 1081 1.86
Hours of operation 12 4 3.00
Cost of Power (INR) 3.25 3.25
Operational Cost per year (INR)
1,548,986 197,304 7.85
Cost Saving (INR) 1,351,682 (per year)
Note: 260 working days considered per year.
Simulations for optimization
Day lighting sensors
LED replacing CFLs
25
300% improvement in Lighting design
2X reduction in the installed lighting load ~3X reduction in lighting energy consumption
26
HVAC Design optimization process
GoalTo 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
27
Heat loads – Heat Sources
35 0C
24 0C
Roof
Walls
Glass
Lights
Fresh air
Equipment People
1
11
28
Building Envelope: Insulation
35 0C 24 0C
22 Watts
35 0C 24 0C
4.4 Watts
45 0C
24 0C55 Watts
35 0C
24 0C 4 Watts
Plain Brick wall
Double brick wall with insulation
RCC roof
Insulated RCC roof
Wall (5X) Roof (13X)
29
Building Envelope: High Performance glazing (5.8 X)
UV Visible Far Infra RedNear Infra Red
.38 .78 50 microns2.60.25
Solar Thermal
2.1
Near Infrared Far Infrared
35 0C
24 0C900 W
540 W360 W
55 W
35 0C
24 0C
900 W
90 W
810 W
12 W
Single glass Spectrally selective double wall glass with Argon filling
30
Case Study: Building in Mysore (1.8 X)
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
No additional cost
Water Vs Air as heat transfer medium
Advanced Cooling Technologies
Water can store 3,400 times more thermal energy per unit volume
than air!
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
32
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
Radiant cooling pipes embedded in the slabs
35 0C 24 0C
4.4 Watts
Double brick wall with insulation
Outside inside
200mm
150mm
33
Design Vs Actual
Efficiencies
Benchmarking
Design Vs Actual EfficienciesSmart buildings – actual data
34
Smart buildings – actual data
35
>200% improvement in overall energy efficiency of new SDBs
Hyderabad (old campus)
Pune Ph-2 Chennai M-City Mangalore Mangala Trivandrum Hyderabad (New campus)
0
50
100
150
200
250
203186
219231
129
90
Uni
ts p
er s
qm
Annual Energy Consumption in Units per SQM (Apr 2011 – Jan 2012)
36
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
• Radiant cooling at no additional cost
37
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
38
• 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
Redefining the standards
39
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.
40
Thank youGuruprakash Sastry
Senior Manager – Green Initiatives | Infrastructure
Infosys Limited
Bangalore 560 100
Tel: +91 80 39148650
M: +91 97399 76191
Email: [email protected]