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: guruprakash_sastry@infosys.com