Example EEMs

Radiant Cooling

Infosys pioneered the radiant cooling technology in India through radiant slab and radiant panel based cooling systems. Infosys building in Hyderabad is the first radiant cooled commercial building in India and the biggest comparison of cooling systems in the world. The building is a live lab split into two symmetric halves, one half with conventional air conditioning and the other with radiant cooling. Data over the last five years show that radiant cooling technology is 30% more efficient than conventional cooling. Energy performance index (EPI) of the radiant cooled building is measured to be about 70 kWh/Sqm/Year, among the lowest in the world for a climate like Hyderabad. (hot and dry)

However, a constraint with the slab based radiant cooling system is that it cannot be installed in existing buildings. Depending on the application there could be concerns around acoustic performance of the building in absence of additional sound absorbing surfaces. In cases where the owner requires high flexibility with respect to changing space usage, radiant slab could offer limitations.

Radiflux panels installed in Infosys building in Bangalore

To overcome the limitations of slab-based radiant cooling system, we implemented the radiant panel-based cooling system in one of our buildings in Bangalore. These are radiant cooling panels that also serve the purpose of a false ceiling in the space. However, they require large ceiling surface area for cooling due to low cooling capacity of 92 W/m2 at 10˚ K Delta. These panels also consist of multiple joints and have high pressure drops, making them difficult to install and maintain. We also realized that the available radiant cooling solutions may not be cost effective in India. While radiant cooling offers numerous benefits, the above limitations seem to constraint its adoption.

Realizing that the available radiant panel based cooling solutions in the market today may not be cost effective in India we developed Radiflux Panels in-house, which use chilled water for cooling. These panels are two times more efficient than other products available in the market, less than half the cost, and need 50 per cent lesser time for installation. Radiflux panels are much more efficient, flexible and easily replicable.

Radiflux was designed and developed to address the challenges with existing radiant cooling systems, especially in the Indian context. Infosys formed a dedicated team whcihwhich worked relentlessly for over a year to develop radiflux in-house. Throughout the development process, the focus was to develop a high efficiency, high quality, reliable, affordable and quick install solution. This solution can be deployed in large scale and has the potential to revolutionize the way cooling is done in buildings in future. We have applied for India, US, and European patents for this product.

The first Radiflux panels are installed at one of Infosys buildings in Bangalore. These panels deliver about two times more capacity for the same coverage area, than other radiant panel solutions available in the market today.


Infosys, has taken the energy efficiency of our buildings to a new level by implementing innovative technologies and smart automation. Our buildings are therefore, among the most efficient globally. At the same time, Infosys has performed major retrofits at our existing buildings, particularly for the air conditioning systems, to bring them to the highest possible efficiency levels. In the last four years, several chiller plants at ourr campuses have been retrofitted, to eliminate wastage, and bring about huge reductions in energy consumption.

The case for a retrofit begins with a detailed audit of all the equipment of the chiller plant, including the chilled water pumps, condenser pumps, cooling towers, and chillers. Over a period of time, the load in the buildings might have undergone changes through the replacement of equipment with newer and more efficient technology.

Chiller Plant Energy Savings

Advancements in technology has resulted in new products such as high‐efficiency chillers and efficient inline pumps coupled to the chiller. Better control valves and automation are available in the market today. The main advantage of retrofits is that the new equipment can be sized very accurately based on measured operating parameters over a period of time, thereby improving efficiencies greatly. All these projects deployed at old chiller plants result in a dramatic reduction in the connected load as well as in the energy consumption. For instance, one of the chiller plants was retrofitted from a primary-secondary chilled water system to a variable primary pumping system. The pumping system was changed from a bank of end-suction pumps to vertical inline pumps coupled to the chiller. The reduced pressure drop in the plant room and the right-sizing and selection of efficient pumps resulted in significant reduction in the connected load in the plant room. In the air handling units, conventional fan systems were replaced with EC (Electronically Commutated) fans leading to nearly 50% reduction in energy. Older air-cooled Variable Refrigerant Volume (VRV) units replaced with chilled-water-based units which are free from harmful refrigerants and require lower maintenance as compared to the previous system.

Accurate M&V: Before vs. After

Additionally, chiller plants are designed with series counter-flow arrangement and every item of equipment has variable speed drives for optimum energy use.

Today, after retrofitting and re- engineering 31 chiller plants, Infosys has reduced the number of chiller plants from 54 to 41 plants. The steps taken have freed up almost a third of the space that was previously occupied in the plant room. Retrofits in air conditioning systems have helped Infosys achieve about 15 MW connected load reduction in the last four years. Most retrofits have a short payback period of less than three years with the life of equipment being more than ten years, thus making them financially viable for implementation.


Intense research in the use of lighting infrastructure across Infosys operations has yielded several innovative solutions and processes. These include technology and design solutions and have been implemented in all buildings that were constructed after 2008 across different campuses in India. The plan is to implement these best practices in all future buildings that Infosys will construct across different campuses.

Daylight panel and vision panel for windows - With the aim of using natural light through the day, all new buildings in our campuses since 2008 have been designed with daylight and vision panels. The window is split into two different types of glass. The upper glass is called the daylight panel and is usually of a higher visible transmittance (more transparent), in order to get natural light into the office space. The lower glass is called the vision panel with low visible transmittance. This type of window is highly efficient because it lets in good natural light with little or no glare, and also minimizes heat gains into the building. In most of the new Infosys buildings, with narrow floor plates (18 m or less), almost 100% of the office space is naturally lit using this design. This ensures the lighting load is very low during the day and provides a comfortable ambience for employees.

Light shelves to improve daylight in office spaces - The light shelf is an architectural element. An overhang fixed between the vision panel and the daylight panel, it extends outside the building as well as inside. The light shelf helps reflect natural light deep into the office space, and provides protection from glare.

Day lit workstations

Volumetric lighting in office spaces - The aim is to provide lighting levels according to global standards, with a focus on the quality of light. Lighting designs are aimed at lighting up the space (volumetric lighting) and not just the employees' desks. This increases the overall visual comfort for employees, and has no additional cost impact.

Accurate lighting design through simulation and controls - Lighting designs are based on simulation software, which indicates the optimum number of light fixtures needed to achieve the required lighting levels. This will eliminate the use of rule-of-thumb designs, thereby reducing lighting loads and subsequently, cooling, and electrical loads. Daylight sensors in perimeter areas and occupancy sensors for all cabins and restrooms reduce the operational costs. Infosys lighting designs are about 50% more efficient than the global American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) standards, and our lighting energy consumption has been reduced to one-eighth of the consumption in old buildings. The accurate design of Infosys lighting systems has involved a lower investment, since the number of fixtures and lamps has been optimized and wastage is thus completely eliminated.

Replacement of sodium vapor lamps with LEDs - Infosys replaced the 250W sodium vapor lamps used for street lighting with 75W LEDs, resulting in a 70% reduction in ourtheir connected load. The payback period for this measure is three years. The life of LEDs is several times higher than that of sodium vapor lamps, thus reducing maintenance or replacement costs. This has been implemented across all Infosys campuses in India.

The exterior lighting at our Chennai Sholinganallur campus has been upgraded with LED light fixtures. We have revamped the entire lighting system and installed low‑wattage LED streetlights to improve visibility for employee movement and safety. We have also replaced the conventional CFL and metal halide light fixtures with efficient LED lights. This has resulted in a reduction in the lighting load by about 37%, as compared to that achieved by the use of conventional light fixtures.

New Façade Lighting

Occupancy Sensors - We have replaced T5 lamps with LED fixtures having in‑built occupancy sensors at our Bengaluru and Thiruvananthapuram campuses. The sensors work on the passive infrared (PIR) technology and detect movements within the coverage area and accordingly alter the lighting levels and switch off the lights when there are no occupants in the room. The highest impact is observed during after-office hours when the building occupancy is low. These light fixtures have reduced our energy consumption by about 40%, as compared to what we were able to achieve using conventional T5 lamps.

Façade Lighting - We have designed and implemented an innovative façade lighting system at one of our buildings at our Mangalore campus that has a built‑up area of 100,000 sq. ft. We have installed LED light fixtures to highlight specific elements of the building façade, making it aesthetically appealing and enhancing viewers’ experience at night. With the use of efficient light fixtures, the lighting load for the entire façade of the building is a mere 246 watts.

Highly efficient building envelope

An efficient building envelope is one of the most important aspects of an energy-efficient building. It is essential to reduce the heat ingress in a building thereby reducing its cooling requirements. Up to a 15% reduction in the peak cooling load and a 6-8% reduction in annual energy consumption can be achieved through an efficient envelope. This covers appropriate orientation, insulated walls and roofs, an optimized window-wall ratio (25-30%), and high performance glazing and adequate shading. All buildings that have been constructed on Infosys campuses have been fitted with efficient building envelopes, reducing the related heat gain to 0.7 Watt per square foot of built up area.

Experience has revealed that the reduction in cooling and electrical equipment provides for the additional investment required for efficient envelopes. This technology has been implemented at buildings that were constructed after 2008 at numerous Infosys campuses.

Additionally, some of the buildings in our campuses, initially designed as glass buildings, have been retrofitted. The façade of these buildings has been improved by reducing the amount of glass, replacing single glass with double glazing, and adding insulation to the walls. This retrofit reduced the amount of heat entering the building and thus resulted in reduced air conditioning energy consumption and increased comfort for the occupants. We plan to implement façade retrofits in other buildings across our campuses.

Electronically commutated (EC) fans

We have replaced our high‑capacity exhaust fans with multiple smaller electronically commutated (EC) fans at our Chennai campus. EC fans consist of fewer components as compared to the conventional belt‑driven fans, thereby reducing the maintenance costs. Also, these fans are smaller in size, with low vibration and noise levels. The installation of EC fans has led to a reduction in energy consumption of nearly 83%, or 60,000 units per year.

Heat pumps

A heat pump is the reverse of a refrigeration cycle. It makes use of the freely available heat energy from ambient air to heat water and generates cold air as a by-product. The hot water generated from heat pumps is used in washers and driers in the laundry, thereby eliminating the use of diesel. We also utilize the rejected cold air from heat pumps to cool the laundry area, making the space comfortable for the laundry staff. For example, diesel boilers have been replaced with heat pumps at the laundry in our Mysore campus, eliminating the use of about 400 liters of diesel per day. In addition to this, heat pumps have also been installed in our employee care centres for supplementing solar hot water system and food courts for generating hot water for dish washing purpose across different campuses. Heat pumps being 3.5 times more efficient than electric heaters, have eliminated the use of 4,000 kW of connected load.

High‑efficiency data centers

We have designed our data centers using emerging technologies to optimize energy consumption. Our new data center at our Bengaluru campus has been constructed with the most innovative designs in the industry. One of its unique features is that all the auxiliaries are DC‑powered by high‑efficiency variable frequency drives (VFD), optimizing energy consumption based on ambient conditions. The 300 kW data center has been designed according to Tier‑3 standards, ranging from 24-27 degree Celsius. The average power utilization effectiveness (PUE) of this data center is estimated to be 1.08. The data center uses a combination of passive cooling and Rear Door Heat Exchanger (RDHx) systems. The passive cooling system, based on direct and indirect evaporative technology, utilizes a minimum amount of fan power.

Cold water is generated from cooling towers for 99% of operating hours annually, and the remaining 1% is achieved through chilled water tapped from the central plant serving the building. Passive RDHx enables rack cooling, where chilled water for cooling is pumped directly to the racks rather than to the entire room. Chilled water is supplied at 21 degrees as against seven degrees in the case of conventional designs, thereby minimizing energy consumption to a great extent. Servers are cooled using passive RDHx without fans.

All the pumps and fans in the data center are based on efficient EC motors, further optimizing the use of energy. Server rack water connections are designed for hot swapping i.e. cooling capacity can be added or removed from the cooling system while the data center is in operation.

Free cooling from DG exhaust heat

Our campuses are equipped with 100 per cent power back-up through diesel generator sets (DG sets) across all locations. Our Chennai campus partially operates on DG power for over six hours a day due to frequent power outages in Tamil Nadu. While this was a challenge, it also offered an opportunity to deploy innovative technology. We implemented vapor absorption cooling technology, which generates cooling from waste heat. DG sets, when in continuous operation, let out a lot of waste heat in form of flue gases.

We installed waste heat recovery system at our DG set plant in Chennai and coupled it with vapor absorption chillers to produce about 400 TR of free cooling from 4,000 KVA of DG sets in operation. On average, we generate about 1600 ton hour of free cooling per day from vapor absorption and reduce electric demand from regular chillers.

Waste water treatment

We strive to recycle and reuse every possible drop of water. Our zero liquid discharge policy helps us achieve this through recycling and reusing 100 per cent wastewater in our aerobic membrane bioreactor (MBR) technology based sewage treatment plants. To make our treatment methodology efficient, we piloted the anaerobic MBR wastewater treatment technology and found that it requires 30% less energy, generates about 60% lesser sludge, and utilizes lesser space compared to the aerobic MBR technology. We are currently planning to implement this technology in one of the sewage treatment plants in our campus.

Capacitive de-ionization (CDI) water treatment

We currently use reverse osmosis (RO) systems for water treatment. However, we have evaluated the capacitive de-ionization (CDI) technology, which is an energy-efficient water treatment system. The reject from the CDI system is about 10-15%, as compared to 40-60% in the case of RO systems. Also, the energy consumption resulting from the use of the CDI technology is expected to be 60% lower than that resulting from the use of RO systems. Hence, we are planning to replace our RO systems with the CDI system to ensure high-quality water treatment and optimum energy use.

Harnessing renewable energy

Infosys aims to meet 100% of its electricity needs from renewables in the next few years. We are the first Indian company to join the RE100 initiative, a global platform for major companies committed to 100% renewable power. In fiscal 2015, about 72 million units of electricity i.e. nearly 29 percent of the total electricity needs was met from renewables. Currently, we have 3 MW of solar PV installations across our campuses in India and plans to increase it to 175 MW in the next few years through on- site and off-site installations. Infosys is also planning a 40 MW solar park in Karnataka which will power our offices in Bangalore, Mysore and Mangalore. Additionally, we are currently in the process of installing a 7 MW of grid- connected solar power plant in our Hyderabad campus.

Solar PV Trial

Infosys is directing our efforts to expand the share of solar energy and is contributing to make this a mainstream power source by demonstrating its viability. As a result, we have undertaken an innovative experiment on the rooftop of one of our buildings in Bangalore. We have installed solar photovoltaic (PV) systems on the building rooftop to harvest solar energy. The unique feature of this experiment is that five different kinds of solar PV technologies, namely, Polycrystalline, Monocrystalline, Hetero Junction Intrinsic Thin (HIT), Copper Indium Selenide Thin (CSI), and Cadmium Telluride Thin (Cd-Te) films, are being compared on the same roof. This project will analyze the effects of different weather conditions on the performance of the PV technologies. This plant is expected to meet over 10% of the total electricity demand of this building.

We are carrying out this study to demonstrate the viability of the best solar PV technology available in the market through continuous monitoring and analysis of energy-generation data in real time.

Continuous monitoring of solar energy generation

For us, it’s not just important for Infosys to be green; we want to lead the way in creating a clean energy future for the development of the society as a whole. We are also working with regulators to bring about policies that encourage and expand the renewables market. For example, we worked with the regulators in Karnataka State to improve regulatory conditions for providing attractive renewable policy. Infosys is on track to get more than 60% of its power in Karnataka state from renewable sources. We are constantly sharing our best practices with the industry and wider communities to demonstrate that these interventions make a strong business case for others to emulate.

Smart building retrofit

We have demonstrated remarkable energy performance of our buildings through smart building designs and retrofits, and by pioneering the use of green technologies. We focus on building automation and controls as a strategy to control and monitor our building comfort, indoor air quality, operations, and energy and water consumption patterns, which in turn help us derive mechanisms to optimize our use of these resources.

We have about 7 million sq. ft. of new buildings, which have smart building management systems. We plan to develop our existing buildings to the highest efficiency standards, and make them intelligent and smart. As part of this initiative, we have undertaken smart building retrofits of 10 of our buildings at our Pune campus, covering 2.7 million sq. ft. of area.

It has been our endeavor to develop intelligent buildings that effectively manage multiple variables such as conditions for occupancy, weather conditions, operating hours, occupant behavior, and equipment efficiencies, thereby creating a healthy work environment for employees and achieving operational excellence. We have implemented a host of efficiency measures, including intelligent control algorithms, scheduling of equipment, occupancy sensors for meeting rooms and cabins, and demand-controlled ventilation systems, to optimize the performance of our buildings.

Our smart buildings use a combination of controllers, sensors, actuators, feedback systems, and energy-saving intelligence to optimize operations. Advanced BACnet Direct Digital Control (DDC) systems integrate multiple systems into a cohesive, single unit, facilitating automated controlling and monitoring. Our robust data-backup mechanisms accurately capture and store data, thereby eliminating the possibility of data loss. Critical alarms due to malfunctions are notified through SMS, to ensure immediate corrective action without affecting efficiency and occupant comfort. These smart buildings can be accessed through Infosys’ intranet system globally, enabling the continuous monitoring and analysis of energy data in real time by our technical experts.

All 10 buildings that were chosen for the retrofit project were retrofitted within three months. This was attained through effective project management and coordination among multiple teams, including our Facilities, HVAC, electrical, water metering, and IT teams. This project is among the biggest and fastest smart building retrofit projects at Infosys. It has resulted in lower operating costs, enhanced equipment life, healthier indoor air quality, and improved occupant comfort and satisfaction.

Our concerted efforts to redesign and retrofit our existing buildings have helped us achieve dramatic reductions in our connected load and energy consumption. Deep green retrofits in our air conditioning systems have helped us achieve a 13.5 MW connected load reduction in the last four years. In fiscal 2015 alone, air conditioning retrofits have resulted in a 3.4 MW reduction in the connected load. Most retrofits have a short payback period of less than three years and can be easily replicated in other commercial buildings.

This case clearly demonstrates that smart building retrofits are viable and cost-effective, on a large scale. The retrofits are expected to save a significant amount of energy, and have an attractive payback period of just four years. With a high replication potential, this data-driven initiative makes an unassailable business case for large companies to undertake smart building retrofits in our existing buildings.

Energy-harvesting wireless technology for wireless switches, sensors, and controls for building automation cuts the time and cost of installation, and enables the efficient use of energy. This technology is based on the energetically efficient exploitation of slight mechanical motion and other potential from the environment, such as indoor light and temperature differences, using the principles of energy harvesting. It is now possible with low investment and minimal disruption to outfit buildings with self-powered peel and stick sensors and switches that seamlessly connect to Transmission Control Protocol (TCP) and Internet Protocol (IP) communications. This technology is being piloted in a new building in Bangalore (MC Building) and based on results will be implemented across new buildings in the future.

Uninterrupted power supply (UPS)

IT offices, with all of our computers for employees and data centers, need uninterrupted power supply (UPS) for maintaining stability of operations even at the time of power fluctuations and outages. Power failure without reliable backup may result in the unavailability of data for users, or could even lead to complete loss of data. Therefore, a robust UPS system with high reliability and efficiency is critical to delivering constant services to our clients and ensuring business continuity.

For optimum energy utilization, we decided to retrofit inefficient UPS systems with efficient ones. A temporary shutdown of systems was required for carrying out this retrofit, which we meticulously planned and implemented in a phased manner, so that our daily business operations would not be affected.

We replaced conventional UPS systems with energy-efficient modular UPS systems, to reduce our installed capacity and energy consumption. Modular UPS systems offer the highest levels of efficiency and flexibility, through a unique system design with cutting-edge architecture, consisting of five to 10 independent, hot, swappable modules. These modules allow for the online interchangeability of UPS systems. Each module within the UPS system has a rectifier, inverter, static bypass, and processor, thereby eliminating single-point failure and supplying continuous power even if one module of the entire system were to fail.

The following table shows the number, installed capacity, and efficiency of the systems, both before and after retrofits, across Infosys campuses in India:

UPS Upgrade Specification
DescriptionOld systemNew systemImpact
Number of UPS systems 350 230 Elimination of 120 UPS systems
UPS capacity 30,200 KVA 20,000 KVA 34% reduction
Efficiency 79% 93% 18% improvement
Number of batteries 19,500 10,000 49% reduction

The original UPS was designed for older computer systems, and is currently overdesigned considering the requirements of present-day computer systems. Earlier, an additional back-up system was an inherent part of the system design aimed at eliminating the possibility of data loss and maintaining business continuity. This additional system would consume a substantial amount of energy, even when it was not in use. With technological advancements, the modular UPS is designed with simple independent systems that contain an optimum number of supporting elements.

UPS retrofits have reduced the installed capacity by 34% when compared to the conventional system. Additionally, the modular system requires fewer batteries than the old system. Owing to the elimination of the number of systems and equipment, we have also witnessed a significant reduction in maintenance and related costs. The following table is an example of a UPS configuration comparison between conventional and modular UPS systems:

UPS Upgrade Performance
ParticularsConventional UPSModular UPS
Design load - 80 KVA 80 KVA x2 20 KVA x5
Operating daylight load - 70 KVA 70 KVA 70 KVA
Actual load on each UPS 44% 70%
Daytime efficiency of UPS 84% 93%
Operating night-time load - 35 KVA 35 KVA 35 KVA
Actual load on each UPS 22% 35%
Night-time efficiency of UPS 73% 92%

We are continuously capturing and analyzing energy data from our UPS systems in real time across all our campuses from one single location through our central command center. This helps us identify inefficiencies and take corrective action, and eliminates energy wastage. In addition to improving system efficiency, this retrofit has also enhanced the reliability of the system, ensuring uninterrupted supply of power to the data centers and computer systems.

The average efficiency of the system has improved by 18%, thereby reducing energy use and energy costs to a great extent. This deep green retrofit has helped us achieve a connected load reduction of about 10 MW in the last four years. For fiscal 2015 alone, UPS retrofits have demonstrated a significant reduction of 4.4 MW in connected load. This retrofit has a short payback period of less than three years, with the life of the system being more than 10 years, making it easily replicable and viable for implementation in other commercial facilities.

Confirm the Business Case and gain management approval for selected EEM’s

Involve Key Stakeholders

The Infosys facilities team is an active stakeholder as they are responsible for all the operations in our buildings, they are responsible for taking over and maintaining the operations of newer buildings with energy efficient design. For older buildings, they are actively engaged in the execution of retrofits, as this involves informing employees about shut downs, providing support in terms of manpower, and supervision of energy efficiency projects.

The energy consumed is metered, measured, and monitored by an internal facilities (energy) team, which is part of the larger Green Initiatives team. The facilities team also takes goals to reduce energy consumption, and works closely with the Green Initiatives team in deploying various energy efficiency measures.

Infosys has a fairly broad spectrum of 3rd party partners. These partners include consultants and service providers related to: glass facades, building management (BMS), sound, metering, energy, lighting, electrical & plumbing, water and sewage treatment STP/WTP, and data centers to name a few.

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