Abstract
CII has developed 20 different rating systems for Green Buildings and Green Infrastructure to suit each type of application, namely residential, commercial, institutional, industrial buildings, townships, SEZs and cities. In recent years, IT/ITES (information technology enabled services) buildings and IT infrastructure have witnessed tremendous growth. This transformation is mainly due to modernization and digitization, which have changed our lifestyle through a quantum jump in speed and ease of communication. Most of our day-to-day activities, businesses and services are being accomplished in very small, densely-packed, sealed buildings, with high energy consumption. These spaces are termed as Data Centres (DC); they have become a necessity and have sprung up all over the country. DCs consume significant energy in processes such as networking, computation and storage. These DCs are invariably operated 24 x 365, with uninterrupted power supply (UPS) to ensure high reliability and availability. This sector has faced serious challenges in terms of sources of reliable power supply for charging of UPS batteries. Hence, energy efficiency in DC facilities has assumed great urgency, leading to the development of an IGBC green rating system specific to DCs. IGBC Green Data Centre rating system was released during the Green Building Congress (GBC) 2016 at Mumbai. It is a first of its kind standard for DCs. It primarily addresses energy efficiency in DCs, while introducing many other green concepts. Green DC rating system offers several tangible and intangible benefits, including reduction in PUE (power usage effectiveness) by 20-25%, water conservation by up to 30%, enhanced IEQ, and wellbeing of staff operating and managing the DC.

Introduction
Data Centres (DCs) have assumed tremendous importance in the last decade as India continues to become more and more digital. They contribute significantly to several national benefits including the ways businesses are done, reduction in fossil fuel use by reducing travel for trade and domestic transactions, saving of man-days involved in day-to-day activities, IT enabled services, speed of communication, employment generation and many more. IT infrastructure and Data Centres are vital in the country’s
vision of a Digital India. Data Centre is defined as ‘a room or building, or portions thereof, including computer rooms being served by the DC systems, serving a total ITE (information technology equipment) load greater than 10 kW and 20 W/sq.ft. (215 W/m2) of conditioned floor area [ASHRAE 90.4-2016]’. DCs are categorized into two
types, namely Internet Data Centre (IDC) and Enterprise Data Centre (EDC). IDCs, also referred as co-location and managed Data Centres, are built and operated by service providers. IDCs are also built and maintained by enterprises whose business model is based on internet commerce. EDCs support many different functions that enable various business models [CII report 2010]. EDCs are evolving partly as a result of new trends in application environment, such as the n-tier, web services and grid computing, to cater to the criticality of the data stored in DCs. Figure 1 shows the typical layout of a Data Centre project. Considering the growth expected in DC industry, interest is growing rapidly to make DCs more energy efficient. Operation and maintenance of DCs is critical; therefore, the Telecommunications Industry Association (TIA) has formulated operating standards to address the requirements of DC infrastructure. An extensive study was carried out by CII in 2012 to collate energy consumption behaviour of DC facilities. Power Usage Factor (PUE) is the globally used and accepted measure for energy efficiency in DCs. The CII study found that PUE varied between 1.4 to 3.0 [CII report 2010]. A joint project of CII-LBNL has also published a policy framework to improve energy efficiency in the DC sector [CII-LBNL 2015]. The reports published by CII and others seem to have given weightage only to energy conservation. Other green parameters such as indoor environmental quality (IEQ), water conservation, building material and resources utilization, and features of project site and planning have not been addressed in these reports. Since IGBC has been involved in developing tools to facilitate stakeholders in adopting green building practices in India, an initiative was taken to develop IGBC Green Data Centres Rating System. The rating system is intended to enable construction and operation of DCs with enhanced resource efficiency, leading to national benefits. Figure 2 exhibits a typical power distribution for a DC facility.

Present Scenario and Future Expansion
IGBC has recently compiled extensive web-based information on DC projects all over India. Our findings are that there are more than 200 well established large capacity data centres currently operational in India. However, many more large capacity data centres would soon be added to support the Digital India initiative. Currently, the largest number of mega data centre projects are located in Maharasthra, primarily in Mumbai and Pune; next in line are Karnataka and Tamilnadu (see Figure 3a). Region-wise future requirement of mega data centres would be in line with the location of Corporate Headquarters: largest in the North, followed by the West, as shown in Figure 3b.

Classification of Data Centres

In a DC, maximum energy is consumed by IT equipment for networking, processing, computation and storage. Cooling is essential to remove the heat generated to sustain the required processes. Since IT equipment runs 24 x 365, HVAC systems also consume significant energy in a DC. There are several technologies and advancements in products and systems that provide ample opportunities for energy conservation. These broadly comprise of the use of efficient IT equipment, highly efficient HVAC systems, virtualization, continuous monitoring of Rack Cooling Index (RCI), continuous performance monitoring, blanking, cold-hot aisle containment rather than mixing of hot and cold air, optimum loading and operation using advanced operation technologies, and other measures. Based on floor area, number of IT racks, number of servers and design IT load, DCs can be classified into various categories as presented in Table 1. Figure 4 exhibits the hot and cold aisle containment in a typical data centre project. The rating system was launched during IGBC’s flagship event ‘Green Building Congress 2016’ at Mumbai on October 8 (Figure 5). Table 2 lists the nomenclature used in DC projects. IGBC Green DC rating system addresses energy efficiency, operation and maintenance, indoor environmental quality (IEQ), water conservation, building material and resources and site planning.

Key Benefits of Green Data Centre Rating System
IGBC Green Data Centre Rating System is designed for both New and Existing Data Centres. The project team can evaluate the applicability of credit points while meeting mandatory requirements to achieve the desired certification level. A project can apply for IGBC Green Data Centre Rating System certification if it can meet all mandatory requirements and achieve the minimum required points. Many new green building materials, equipment and technologies are being introduced in the market. With
continuous up-gradation and introduction of new green technologies and products, it is important that the rating programme also keeps pace with the subsequent standards
and technologies. Therefore, the rating programme will undergo periodic revisions to incorporate the latest advancement. It is important to note that project teams applying for rating should register their projects with the latest version of the rating system. During the course of implementation, projects must have the option to transit to the later version of the rating system if it is announced midstream of project completion.

Unique Aspects of Rating System
• Emphasis on DC equipment, rather than building elements
• Addresses both the IT areas and the non-technical spaces
• Encourages management information systems, energy management and monitoring
• Addresses air quality in IT and non-IT spaces
• O&M guidelines enhance reliability and availability
• Site visits before award of rating
 

Tangible and Intangible Benefits of Rating System
Tangible benefits
• 20-25% reduction in PUE
• 25-30% reduction in water consumption, if water cooled chillers are used for project
Intangible benefits
• Enhanced Indoor Environment Quality
• Improved waste management practices including e-waste and other hazardous and non-hazardous waste
• Health and well-being of staff
 

Key National Benefits of Rating System
• Introduction of green principles to the sector
• Reduced power demand for DC
• Enhanced renewable energy penetration
• Diversion of water saved to other potable usages
• Responsible handling and disposal of waste
 

References
1. BSR/ASHRAE Standard 90.4P, Energy Standard for Data Centres, ASHRAE, 1791 Tullie Circle, NE, Atlanta, 2016
2. CII-BEE, Energy Efficiency Guidelines and Best Practices in Indian Data Centres, Bureau of Energy Efficiency (BEE), Ministry of Power, Government of India, 2010.
3. CII, Energy Efficiency in Indian Data Centres – Present Trends and Future Opportunities, December 2012
4. CII-LBNL, Accelerating Energy Efficiency in Indian Data Centres: Final Report for Phase I Activities, December 2015.