Cloud Computing: Grey or Green?

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1 Brassersplein CT Delft Postbus 5050 NL-2600 GB Delft TNO report Cloud Computing: Grey or Green? On the energy-efficiency and sustainability of Infrastructure-as-a- Service T F infodesk@tno.nl FINAL VERSION Date 23 March 2012 Original Author(s) English Translation Review Mark Bastiaans, Bram Spitzer, Daniël Worm, Freek Bomhof Commissioned by SURF Pieter Meulenhoff Number of pages 33 Number of 2 appendices: Client NL Agency [AgentschapNL] Steering group Frank Hartkamp (NL Agency), Dirk Harryvan (MAN Systems), Gerard van Westrienen (SURF), Jan-Willem Tellegen (Green IT Consortium Amsterdam), Paul Dekkers (SURF) Project name Green Clouds Project number This publication is subject to Creative Commons licence Attribution Non-commercial No Derivative Works (CC BY-NC-ND 3.0).

2 TNO report 2 / 33 Management Summary Cloud Computing: Grey or Green? On the energy-efficiency and sustainability of Infrastructure-as-a-Service Organisations that wish to reduce their energy consumption find themselves faced by a number of choices. One of these choices is to reduce the amount of energy consumed by their ICT. This choice brings further options, the one beingto address the consumption workstations by means of active energy management, the other to address the consumption of the servers. Cloud computing is receiving increasing attention in connection to the consumption of servers: it can help reduce costs. It is often believed that cloud computing is automatically energy-efficient. This is not necessarily so; in fact, cloud solutions can vary considerably in this respect. Cloud computing is defined as on-demand, dynamic access to a collection of ICT resources (such as networks, storage, processing, applications, and services) over a network. This involves more than merely using service such as webmail or webbased documents. Organisations often choose cloud solutions due to the cost advantages: capacity that is only needed temporarily is only utilised (and paid for) when it is really necessary. This study focuses on Infrastructure-as-a-Service clouds i.e. clouds in which storage and processing capacity is made available as a service with the main focus on the question When is a cloud green?. Green in this context is defined primarily in terms of energy consumption, but the associated CO2 emissions are also considered, i.e. the sustainability of the process of generating the consumed energy. The energy consumption of a cloud depends mainly on the efficiency: is all ICT equipment fully utilised? An unused server could be turned off or phased out. Cloud computing offers the possibility of utilising dynamic ICT resources, i.e. it enables turning resources on and off as and when necessary. It also enables optimally utilizing the ICT resources that are available. Often the use of cloud computing alone implies improved efficiency. The effectiveness of the energy consumed effectiveness being the proportion of the energy is used for ICT and how much is needed for cooling systems and other support equipment - is also relevant. Another factor that needs to be taken into account concerns the emissions resulting from the energy consumption. Specifically for cloud computing, location also plays a role. A cloud is characterized by storage and processing take place at a certain distance from the end-user. Therefore, The energy that networks consume in order to transport the data must also be taken into account. Cloud computing also enables that storage and processing takes place at a location where energy i.e. locally generated energy is cheapest (including the transport costs) and greenest. An organisation that intends to make use of green clouds will likely assess cloud providers by means of frameworks such as the CO2 Performance Ladder. For cloud providers, some of the main considerations for providing green clouds will be promoting efficient use and implementing effective capacity management. For cloud

3 TNO report 3 / 33 customers, energy efficiency, energy effectiveness, and emissions by the services utilised should be considered in internal (TCO) calculations. A summary of the most important features: A cloud provider is greener if: The servers are fully utilised: the number of servers that are switched on but are not doing any useful work has been minimised (efficiency); techniques that can be used to this purpose are e.g. virtualisation, scheduling and provisioning and energy-efficient hardware; The energy that the data centre consumes is mainly consumed by the servers; in reverse: only a minimum of energy is necessary for cooling, lighting, and other systems (effectiveness); frameworks and metrics that can be used to measure effectiveness include frameworks such as OpenDCME, BREEAM, LEED and metrics such as Green Grid; The energy consumed leads to the minimum possible emissions; in other words, it has been generated sustainably; The data centre is not too far away from the users so that transporting the data consumes less energy; The energy is generated at a location close to the data centre so as to minimise transport losses. Cloud service customers should take the following into account: Provider assessment by means of a framework such as the CO 2 Performance Ladder; Inclusion of energy efficiency (or another sustainability metric) in their own management systems and management reports; Allow for the energy efficiency of ICT use in the internal pricing for services; Encourage efficient use, e.g. by encouraging that computationally intensive but non-interactive tasks (that cause little network traffic) are processed within the cloud.

4 TNO report 4 / 33 Summary Cloud computing is on demand, dynamic access to a collection of ICT resources (such as networks, storage, processing, applications, and services) over a network. This study assumes Infrastructure-as-a-Service clouds: storage and processing capacity is made available as a service, either as a public cloud (at one or more central locations for various customers), as a private cloud (the customer creates its own cloud for its own end-users), or as a federated cloud (different customers share their cloud facilities with one another, consequently also acting as providers for one another). A federated cloud that is used within a closed group for example only by participants from a single sector is sometimes called a community cloud. Cloud computing offers advantages: it can be both cost efficient and energyefficient compared to ICT that is managed in the traditional way by individual organisations. This report concerns the question When is a cloud green? In this study, we look at green primarily in terms of energy consumption, but the related CO 2 emissions are also considered: how sustainable was the process of generating the energy consumed? The energy consumption of a cloud depends mainly on the efficiency: are the ICT resources all actually utilised to the full? A server that is not actually used can perhaps better be turned off or phased out. Cloud computing offers the possibility of utilising dynamic ICT resources in other words turning them on and off as and when necessary and also of making optimum use of the ICT resources that are available. The use of cloud computing already often means improved efficiency. The effectiveness of the energy consumed is also relevant: what proportion of the energy is used for ICT and how much is needed for cooling systems and other support equipment? Another factor that needs to be taken into account concerns the emissions resulting from the energy consumption. Specifically in the case of cloud computing, the location also plays a role. It is characteristic of a cloud that storage and processing take place at a certain distance from the end-user. The energy that networks consume in order to transport the data must therefore be taken into account as well. Cloud computing also makes it possible for storage and processing to take place at a location where energy i.e. locally generated energy is cheapest (including the transport costs) and greenest. An organisation that intends to make use of green clouds will assess cloud providers by means of frameworks such as the CO 2 Performance Ladder. For cloud providers, some of the main considerations for providing green clouds will be promoting efficient use and implementing effective capacity management. For cloud customers, energy efficiency, energy effectiveness, and emissions by the services utilised can be allowed for in internal (TCO) calculations. The ICT architect working for a cloud provider that wishes to set up a green cloud will need to take a number of matters into consideration. These include maximising utilisation through virtualisation, efficient scheduling and provisioning methods, selection of the location (for example a location close to the end-user or close to the power station), use of energy-efficient ICT and related resources, use of sustainable energy, and sustainably constructed data centres.

5 TNO report 5 / 33 Contents Management Summary... 2 Summary Introduction Background: the rise of cloud computing, green ICT The problem to be considered: green, but when and how? Scope: IaaS clouds; environmental effect of energy consumption, CO When is a cloud green? What is a green cloud? Cloud: dynamic ICT, on demand, payment according to usage Green: minimising the carbon footprint per business unit What factors are important in attempting to achieve greenness? Efficiency and effectiveness: minimising energy consumption Greenness factor: emissions from energy consumption; embedded carbon Cloud-specific: network between provider and customer is other consumption ; allow for cost of transporting energy How can a cloud be made green? What changes are necessary within organisations for there to be a green cloud? Ensure green policy; from strategy to ICT architecture to procurement Make greenness transparent What service models and business models contribute to a green cloud? Make efficiency and effectiveness the basis for ICT architecture Make it attractive for the (internal) end-customer to purchase green services How can the design and practical implementation of ICT be made green? Make ICT resources more efficient: virtualisation, efficient scheduling, and provisioning methods Make ICT resources more effective: optimise distance, utilise energy-efficient hardware, other resources Reduce the carbon footprint What specific steps must be taken? Communicate about green Clarify the carbon footprint Include the whole cloud chain Determine what carbon footprint metric is relevant Aim for efficiency, effectiveness, and carbon footprint Use the cloud efficiently... 26

6 TNO report 6 / 33 1 Introduction 1.1 Background: the rise of cloud computing, green ICT The topic of cloud computing is receiving increasing attention in the world of ICT. Compared to traditional ICT, it is seen as a means of dealing more efficiently and effectively with the available sources such as hardware and energy. A Forrester report refers to cloud computing as an aid to speeding up green ICT and mentions the aspects of energy efficiency and resource efficiency. 1 In the Netherlands, NL Agency [Agentschap NL] and SURF are collaborating with a number of parties with efficiency and effectiveness in mind to determine how to set up a community cloud for certain target groups, for example the higher education and research sector. Under the designation green ICT a lot of work has also been done nationally and internationally to improve the energy efficiency of individual data centres in particular. This has resulted in indicators, measures of performance, technology, best practices, and practical guidelines. NL Agency has requested TNO to survey the current relationship between cloud and green and to draw up a report that can assist in deciding on and constructing a green cloud. 1.2 The problem to be considered: green, but when and how? NL Agency works to encourage the various sectors of the Dutch economy, including the ICT sector, to be energy-efficient. This has resulted in a number of Long-term Agreements (in Dutch MJAs ) with various sectors. The advent of cloud computing has led to NL Agency wishing to determine how this type of ICT service delivery can be made as energy-efficient as possible. This report attempts to answer the following questions: 1. When is a cloud solution green? a. What is a green cloud? b. What factors are important in attempting to achieve greenness? 2. How can a cloud be made green? a. What changes are necessary within organisations for there to be a green cloud? b. What service models and business models contribute to a green cloud? c. How can the design and practical implementation of ICT be made green? Finally, the report considers what concrete steps can make a cloud greener, in other words how a green cloud can actually be created. 1.3 Scope: IaaS clouds; environmental effect of energy consumption, CO 2 This report deals specifically with Infrastructure-as-a-Service clouds (IaaS); when used in this report, the term cloud refers to such clouds. The report does take 1 Cloud Computing Helps Accelerate Green ICT Doug Washburn and Lauren E. Nelson (Forrester) - 30 June 2011

7 TNO report 7 / 33 account, however, of both infrastructure and application aspects: an IaaS service is often a service that is not purchased by end-users but by an IT organisation. That organisation will construct applications and services for end-users based on an IaaS service and those applications and services are often a decisive factor in using the IaaS cloud. This report takes energy consumption and therefore also CO 2 emissions (as CO 2 equivalents) as the measure of environmental impact ( greenness ). The report does not attach any value judgment to the environmental effects of CO 2 emissions. 2 In addition to the environmental impact of CO 2 emissions, there are other environmental effects that can play a significant role. One example involves the way extracting and processing many of the rare earth metals used in electronic equipment has a toxic impact on the environment. Large areas are also often affected by extraction. Some energy generation produces radioactive waste. This report does not deal with these environmental effects but that does not mean that they are unimportant. 2 Indirectly, a consequence is associated with the emission of greenhouse gases: it is linked to a weighting (IPPC a). That weighting means that each greenhouse gas is assigned a value with respect to CO 2. N 2O, for example, has a value of 298 kg CO 2-eq/kg.

8 TNO report 8 / 33 2 When is a cloud green? This section of the report deals with the question When is a cloud green? That question can be broken down into the following components: a. What is a green cloud? A definition is provided. b. What factors are important in determining greenness? An indication will be given of how each factor can be expressed. 2.1 What is a green cloud? In order to define a green cloud, we need to consider the terms green and cloud Cloud: dynamic ICT, on demand, payment according to usage The most frequently quoted definition of cloud is that by the United States National Institute of Standards & Technology (NIST). 3 A model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction. That definition can be summarised as on demand, dynamic access to a collection of ICT resources (such as networks, storage, processing, applications, and services) over a network. This report will deal with one specific services model, namely Infrastructure-as-a-Service (IaaS), i.e. the provision as a service of the basis for every ICT service: storage and processing. As an analogy to cloud computing, we can take the availability of a taxi pool. Customers can temporarily hire the taxis and on demand: one pays only for using the taxi; management and maintenance are dealt with by the taxi company. This is different to in-house ICT, which can be compared to a company owning its own fleet of cars. The taxi analogy is used in this report to illustrate a number of aspects of green clouds. In the case of a cloud, there are two types of stakeholders: providers and customers. The provider supplies the cloud service (storage or processing capacity) while the customer purchases it. An organisation within a cloud chain can in fact act as both provider and customer. Unlike with in-house ICT, the bandwidth and quality of the network connection between the provider and the customer is essential because the cloud provider may be located a great distance away from its customers geographically. Not only does the geographical distance between supply and demand require even greater attention to the interconnecting network than in in-house IT scenarios, it 3 NIST definition of cloud computing:

9 TNO report 9 / 33 often also raises organisational and legal issues. Those issues will not be dealt with in the present report because they are separate to the specific problem to be considered Green: minimising the carbon footprint per business unit In an IaaS cloud, the physical location, ownership, and management of the ICT resources of storage and processing have shifted towards the provider. This means that the provider can not only pool ICT resources so as to utilise them more effectively and efficiently; increased scale also means that it can deal more effectively with suppliers. This means not only that fewer ICT resources will be needed in order to meet the total combined demand by customers; the total amount of energy consumed in order to operate those resources will also be lower because the customers themselves will need to keep less (over)capacity operational (or indeed none at all). In this report, green is taken to mean minimising the carbon footprint per business unit. To continue the taxi analogy: green means minimising the quantity of CO 2 released due to use (combustion of fuel) and the CO 2 involved in manufacturing and scrapping the taxi, calculated per passenger. The use component of the carbon footprint depends on the energy consumption of the taxis in the pool when they are on the road, while the manufacturing/scrapping component depends on the consumption of materials when the taxis were manufactured. In the case of ICT, these terms can be defined as follows: Carbon footprint: the carbon dioxide impact during: the use phase. This comprises the emissions due to the energy consumption relating to the use of ICT resources. This component is variable depending on the use made of the equipment concerned. the manufacturing and scrapping phases. This involves the resources themselves and therefore such things as the consumption of materials (embedded carbon) and energy consumption involved in manufacturing and scrapping the resources. This component is not variable and can only be influenced when purchasing equipment. 2.2 What factors are important in attempting to achieve greenness? For ICT in general, three factors are relevant in attempting to achieve greenness in the use phase, i.e. minimising the carbon footprint: the efficiency and effectiveness of the energy consumption; and the greenness factor, which is dependent on the emissions due to energy consumption. This report assumes that these three factors are far less significant during the manufacturing and scrapping phases than in the use phase. Section explains why that is the case.

10 TNO report 10 / 33 There are a number of aspects that need to be taken into account in calculating these factors specifically for cloud computing. The factors themselves and the cloud-specific aspects will be explained below. Annex A explains how the various different factors can be combined into a single greenness figure Efficiency and effectiveness: minimising energy consumption As we have already seen, the carbon footprint and therefore the greenness can be divided up into a use component and a manufacturing/scrapping component. The ratio between these two components is extremely important. An EU report notes that in the case of office computers the ratio between the carbon footprint in the use phase and during manufacturing/scrapping (given a five-year write-off period) is approximately 66 : Estimates for servers which are switched on longer than office computers and more fully utilised suggest a ratio of 90 : The above estimates indicate that the greatest benefit can be achieved by minimising energy consumption per business unit. In the case of the taxi, the energy consumption involved in conveying a single passenger must be minimised. This can be achieved by utilising energy as usefully as possible, i.e. as regards both the efficiency and effectiveness of the energy consumption. In taxi terms, these two concepts can be explained as follows: Efficiency: the level of utilisation of the taxi pool, i.e. the ratio between: How many people are conveyed by the taxis; and How many people fit in the whole pool. In practice, a taxi company that owns the taxis in the pool will attempt to convey as many people as possible. This will optimise the utilisation per taxi and also the size of the pool. Effectiveness: the relationship between: The energy consumption of the taxi pool, i.e. the energy consumed in order to convey passengers; and The total amount of energy needed to convey passengers, i.e. including the energy needed for such things as garaging and servicing the taxis. In actual practice, a taxi company will purchase economical taxis that do not require much servicing, and will deploy a mix of larger (i.e. more effective) and smaller taxis. This means that not only the amount of energy consumed for servicing will be reduced but also the quantity of embedded carbon in the necessary garage facilities. 4 European Commission DG TREN Preparatory studies for Eco-design Requirements of EUPs Lot 3: Personal Computers (desktops and laptops) and Computer Monitors Final Report (Task 1-8) 5 Fact File: Carbon Reduction Measures - GLA

11 TNO report 11 / 33 For ICT in general, these two factors can be defined as follows: Effectiveness: The ratio between ICT service-related energy consumption and other energy consumption, where: o ICT service-related energy is actually consumed for storing and processing information (servers, storage, and internal network connections); and o Other energy consumption for everything else (for example management, accommodation, cooling, external network connections, energy transport costs). Efficiency: the utilisation of ICT-related resources, i.e. the extent to which the ICT resources are actually utilised Metrics: Compute Efficiency and Power Usage Effectiveness Work has been going on in the world of green ICT for some years now to create metrics for efficiency (Compute Efficiency; ce) and effectiveness (Power Usage Effectiveness; PUE). Figure 1 shows the relationship between the various different types of energy consumption associated with ICT resources and frequently used metrics for the effectiveness and efficiency of ICT. These metrics are described in Annex A. Energy Consumption ICT service energy consumption (clients, servers) ScE, DCcE PUE(x) Utilisation of ICT service energy consumption Other energy consumption (accommodation, cooling, management,...) Figure 1 - Energy consumption by a party within the chain Efficiency and effectiveness can not be viewed separately. A provider can greenwash a data centre by making it more effective overall by installing effective resources, but if those resources are not fully utilised, the energy consumption per business unit may in fact be increased Greenness factor: emissions from energy consumption; embedded carbon Minimising energy consumption does not automatically result in a greener cloud. For the cloud to be genuinely green, efficiency and effectiveness must be combined with the following factors: Emissions from energy consumption, i.e. the greenness of use; and Embedded carbon, i.e. the greenness of manufacturing and scrapping. These two factors will be explained below. As already mentioned, embedded carbon is less important than emissions.

12 TNO report 12 / Emissions from energy consumption: CO 2 emissions per kwh Energy consumption can be reduced by means of effectiveness and efficiency. Greenness, however, involves more than those two criteria: the emissions from the type of energy consumed are also relevant. Here too, this factor can not be viewed separately if we wish to prevent greenwashing : an efficient and effective provider that utilises grey electricity may be less green than a provider that is less efficient and effective but that uses green electricity. To continue the taxi analogy: Emissions: the carbon dioxide released during the combustion of fuel (for example diesel, petrol, electricity) that the taxi utilises. In practice, a green taxi is only genuinely green if it causes the minimum possible emissions. The CO 2 emission level per kwh has been calculated for various different fuels and methods of generating energy, ranging from petrol to gas and from coal to wind Embedded carbon: use of energy and materials; emissions during scrapping When calculating the embedded carbon in ICT resources, account is taken of their manufacture and scrapping. In the case of manufacture, it is relevant which materials are used. Different materials involve different extraction and processing methods, meaning that the energy required to manufacture a given product will differ. In the case of the manufacturing of a product, all the CO 2 emissions are taken into account, from extraction of the raw material to the actual product. The materials used are also important where scrapping ICT equipment is concerned. Some materials in particular metals in their pure form can be recycled effectively, thus reducing CO 2, because no new raw materials need to be extracted. Plastics, however, are frequently incinerated; this causes the emission of CO 2 (in addition to generating a small quantity of energy). Table 1 gives an indication of the embedded carbon in client hardware (desktop PCs, laptops). Table 1 - Embedded carbon in client hardware electronics. Based on IPCC 2007 GWP 100a V1.02, data from > 2005 (source: TNO) Appliance Embedded kg CO 2) Desktop PC (without peripherals) 271 Laptop 610 CRT monitor 253 LCD monitor 6392 Keyboard 26 Mouse Metrics: emission factor for energy The emission level per kwh is known for numerous different types and mixes of energy (for energy from mixed sources, for example both coal and water power). It is therefore possible to determine an emission factor for the type of energy used that complements the efficiency and effectiveness and metrics. Annex A explains

13 TNO report 13 / 33 how these emissions can be taken into account when attempting to achieve greenness Cloud-specific: network between provider and customer is other consumption ; allow for cost of transporting energy Providers and customers within a cloud chain are connected by a network (Figure 2). Network connections consume energy. Estimates in an IEEE report state that as storage and processing shift entirely into the cloud, the proportion of energy utilised for transport will be 10% (private cloud) to 25% (public cloud) of the total. 6 However, the efficiency and effectiveness of a cloud can save so much energy that it may be worthwhile incurring these extra energy costs; after all, they can be amply compensated for. Chain Energy Consumption ICT service energy consumption... ScE, DCcE PUE(x) Other energy consumption (accommodation, cooling, management,...) Network... Figure 2 Energy consumption by a chain Total energy consumption must consequently be viewed as a problem for the chain as a whole, in which the energy consumption of the network is also being minimised. Given that the network between provider and customer is an essential component of a cloud chain but not a primary service (in the case of IaaS the primary services are storage and processing), the energy consumption of the network connecting provider and customer must be categorised as part of other energy consumption. Transporting information via a copper or optical fibre network and transporting electricity via high/medium/low-tension cables both consume energy. In the United Kingdom, for example, transmitting electricity costs 2% in transmission losses. 7 A cloud provides the option of consolidating storage and processing, both in house and externally. It may perhaps be better to relocate storage and processing to where energy is cheapest or cleanest rather than bringing cheap or clean energy to the location. This literally means bringing energy to the provider/customer or vice versa. The cost of transporting energy therefore needs to be taken into account when determining energy consumption. 6 Green Cloud Computing: Balancing Energy in Processing, Storage, and Transport Jayant Baliga, Robert W. A. Ayre, Kerry Hinton, Rodney S. Tucker (IEEE Fellow) 7 Investigation Into Transmission Losses on UK Electricity Transmission System June BC6A81EFA09B/26920/ElectricityTransmissionLossesReport1.pdf

14 TNO report 14 / 33 3 How can a cloud be made green? This section of the report deals with how a cloud can be made green. That question can be broken down into the following components: a. What changes are necessary within organisations for a green cloud? In general, this section will deal with greenness within organisations; cloud-specific aspects will not be considered. b. What service models and business models contribute to a green cloud? Here, consideration will be given to the use and service delivery aspects of green clouds. c. How can the design and practical implementation of ICT be made green? Here, consideration will be given to the ICT infrastructure elements under clouds. A summary of criteria and measures can be found in Annex B. 3.1 What changes are necessary within organisations for a green cloud? We will deal below with organisational aspects associated with ICT-related greenness within an organisation. Greenness criteria and measures are: Who? Criterion Measure(s) Factor Customer Ensure green policy; from strategy to ICT architecture to procurement Assess organisations with the aid of the CO 2 Performance Ladder or similar framework(s); choose which. - Provider, customer Make greenness transparent Implement a greenness performance management system for internal and external use Ensure green policy; from strategy to ICT architecture to procurement Currently, most organisations are driven by effectiveness and efficiency. In order to be truly green, specific targets are necessary regarding emissions (for example a reduction in tons of CO 2 ). Organisations will include these criteria as a CSR target in their strategy. However strategy alone is not enough. Most operational processes will focus on achieving the targets as efficiently and effectively as possible from a financial point of view. Here, however, emissions are often ignored and green is interpreted as as cheaply as possible (i.e. efficient and effective energy consumption). Certain organisations (including manufacturers with a particular production capacity and energy suppliers with a certain generating capacity) are tied to the purchasing of emission rights and it is standard practice to simply buy off those rights. Research has shown that the costs for this will be passed on to the organisation s customers without the intended greenness effect being achieved. 8 Efforts to achieve - 8 Direct and Market Effects of Enforcing Emissions Trading Programs: An Experimental Analysis

15 TNO report 15 / 33 greenness will therefore need to be at the level of the individual process, beginning with the ICT architecture process. The ICT architecture process converts the organisation s strategy into ICT strategy and design (and vice versa) and consequently plays a key role in minimising the carbon footprint of ICT. By implementing measures in the area of consolidation and standardisation (including application rationalisation, service provision, virtualisation) at service and infrastructure level, ICT resources are made more uniform and can be pooled, and cloud principles can be applied. Those principles alone can already make it possible to achieve greater effectiveness, improved efficiency, and/or lower emissions. A number of these measures are described in the following sections of this report. Other operational processes will need to support these measures. One operational process that will need to provide this support is the ICT procurement process. In order to incorporate greenness here, emissions would need to be an important factor in the procurement process. The CO 2 Performance Ladder (originally developed by ProRail) is a way of encouraging CO 2 -aware action on the part of companies tendering for contracts, both in their own operations and when implementing projects. This involves, in particular, energy-saving measures, the efficient use of materials, and the use of sustainable energy. 9 The ladder (Table 2) can be viewed as a maturity model for green-aware organisations; it indicates various maturity levels for various different aspects. Table 2 - The CO 2 Performance Ladder (skao.nl) Level Description 5 The company has a CO2 emissions inventory of its most important suppliers. The company can demonstrate that the objectives for levels 3 and 4 have been attained. The company is publicly committed to a government or NGO CO2 reduction programme, and is able to demonstrate that it is making a relevant contribution to an innovative CO2 reduction project. 4 The company has identified its chain emissions in outline terms, and chain analyses have been carried out for two relevant chains. The company has quantitative objectives for its chain emissions. The company is in dialogue with relevant parties (government bodies and social organisations) and can demonstrate its role as the instigator of sector and chain initiatives in the field of CO2 reductions. 3 The company has an official CO2 emissions inventory that has been drawn up in accordance with the ISO (GHG) standard, and which has been verified by an independent organisation. The company has quantitative objectives for its own (scope 1 and 2) CO 2 emissions. It communicates internally and externally in relation to its CO 2 footprint on a structural basis and actively participates in at least one sector and chain-based CO2 reduction initiative. 2 The company has quantified its energy flows and formulated a qualitative objective for saving energy and using renewable energy. Internally, the company communicates its energy policy on a structural basis and takes a passive role in at least one sector and chain-based CO 2 reduction initiative. 1 The company has identified its energy flows in qualitative terms and has a list of potential options for saving energy and using renewable energy. Internally, the company communicates its policy in relation to energy-saving and renewable energy on an ad hoc basis and is aware of sector and chain-based CO 2 reduction initiatives. James J. Murphy and John K. Stranlund - University of Massachusetts Amherst - Department of Resource Economics - Working Paper No The CO 2 Performance Ladder:

16 TNO report 16 / Make greenness transparent Besides greenness needing to be incorporated into the way an organisation works, it will also need to be measured and reported at all levels of the organisation. Performance management i.e. measuring whether processes operate as they are intended to operate covering effectiveness, efficiency, and emissions will need to be available at all levels of the organisation, ranging from real-time ICT monitoring tools to management dashboards. This transparency applies not only internally for managers and employees but also externally: reporting on greenness will not only need to benefit the external fulfilment of an organisation s CSR targets but also the actual impact of these on the organisation prior to greening. One example of an organisation that is attempting to make greenness transparent throughout the organisation is Google. 10 Another example is the above already mentioned GreenQloud, who indicate the level of greenness of their provisioned cloud services in understandable terms such as the number of barrels of oil used or the number of miles driven by a car. Various metrics will need to be utilised at different levels of the organisation; PUE says little in the language of company targets, but the carbon footprint per user, citizen, student, or transaction does. In order to apply this metric, the detailed metrics described in the previous section can be utilised at lower levels. 3.2 What service models and business models contribute to a green cloud? We will deal below with supply and demand measures to make a cloud greener. What is relevant here is the interplay between customers for IaaS services and those within ICT organisations, often the service manager who provide them. Greenness criteria and measures are: Who? Criterion Measure(s) Factor Provider Make efficiency and effectiveness the basis for ICT architecture. Customer Make it attractive for the (internal) end-customer to purchase green services. Promote efficient use: non-interactive services; spot instances. Consolidate ICT resources and implement capacity management. Include greenness in (internal) pricing (TCO) so as to guide demand towards greenness. Efficiency, effectiveness Make efficiency and effectiveness the basis for ICT architecture Research by the IEEE 5 has shown that besides the fact that energy consumption by networks within the cloud chain can increase to some 25% of total consumption the network is most heavily loaded and therefore most utilised when use is - 10 Google Green

17 TNO report 17 / 33 made of interactive services. Energy consumption will be greatest in the case of intensive interactive use of virtual machines and hard disk space over the network, for example when a remote desktop or thin-client environments are provided; consumption will be lower with less interactive use, for example large-scale computing jobs which once started require little interaction. It is therefore important for the service manager to optimise this kind of use, for example by locating interactive cloud services closer to home (thus requiring a shorter connection) or not in an IaaS cloud at all. Secondly, efficient use of the cloud can be promoted by means of pricing. Measures that have already been taken in order to set up a cloud including consolidation of ICT resources and capacity management (by type and number of resources) often mean greater effectiveness but not greater efficiency. In order to increase efficiency i.e. to maximise utilisation of a cloud it is important to run as much storage and processing as possible (virtual machines and storage buckets ) in the cloud at any moment of the day ( load balancing ). The service manager can influence behaviour on the part of end-users of an IaaS cloud, for example the time when they make use of the cloud. Amazon the biggest IaaS provider offers spot instances, meaning that virtual machines have different prices per click at different times. Amazon does this so as to run a number of virtual machines at any moment in the day that call on the processing capacity of their cloud in the best possible way Make it attractive for the (internal) end-customer to purchase green services. The Total Cost of Ownership (TCO) of ICT is an important pricing metric that is used to indicate the ICT costs (efficiency) per ICT service or resource, and also to calculate business cases in ICT organisations. At the moment, this cost metric is of a financial nature and all the costs incurred for procurement, scrapping, use, and management of ICT are all simply lumped together in the same category. Greenness is normally not included. To return to the previous point about making greenness transparent: it is important to refer in reports explicitly to the greenness components of TCO, for example emissions. Given that emissions by ICT can be converted into emission rights when the present report was drawn up the standard price of emission rights was euros per ton of CO 2 emissions can be counted as part of TCO so as to arrive at a green figure for TCO. Another and probably better incentive is to include total energy consumption (of the entire cloud chain) in de TCO; energy is, after all, more expensive than the associated emissions. 3.3 How can the design and practical implementation of ICT be made green? This section discusses measures that can make the design and practical implementation of ICT and consequently of clouds greener. This is not only relevant to a cloud provider but also to customers because they can benefit from greener (client) ICT. The measures below were drawn up on the basis of research and recommendations from various sources. One model that includes many such

18 TNO report 18 / 33 measures in a single cohesive data centre-specific model is the OpenDCME model. 11 That model examines various different aspects of a data centre; it can be used both to determine the maturity of those aspects and also to improve them. The EU has also drawn up a Code of Conduct for Data Centres that prescribes many of these measures. 12 Greenness criteria and measures are: Who? Criterion Measure(s) Factor Provider Make use of virtualisation. Determine the extent of Efficiency virtualisation. Provider Make use of efficient scheduling and provisioning methods. Check whether use is made of efficient scheduling and provisioning methods. Efficiency Provider, customer Provider, customer Optimise the distance between customer and provider so as to balance network and transport consumption. Use energy-efficient server hardware. Use energy-efficient client hardware. Use energy-efficient other resources. Weigh up different energy consumption scenarios (varying the location of the provider and the customer) in terms of ICT resources, network, and energy transport and make a choice. Assess using OpenDCME, EU Code of Conduct for Data Centres, Energy Star, or similar standards and norms; choose which. Provider Use sustainable energy. Use the Fuel Mix Label [stroometiket] when selecting an energy provider; take account of this when optimising the distance. Provider Construct sustainable data centres. Use BREEAM, LEED or similar standards/seals of approval; choose which. Effectiven ess Effectiven ess Carbon footprint Carbon footprint Make ICT resources more efficient: virtualisation, efficient scheduling, and provisioning methods. Improving the energy efficiency of the ICT resources by such means as virtualisation will generally lead to better utilisation of ICT sources Make use of virtualisation. It is not only CPUs but also other components such as hard disks, memory, and network equipment that consume energy, meaning that even when a server seems 11 OpenDCME 12 EU Code of Conduct for Data Centres

19 TNO report 19 / 33 to be idle, it may still be using up to 60% of its maximum capacity. One way of increasing the energy efficiency of data centres is to virtualise the servers, with each server being divided up into VMs (virtual machines). Utilising several VMs on a server is known as server consolidation ; it means that fewer actual physical servers are necessary and that less energy is therefore consumed. 13 Most if not all cloud providers are already using this technology: a cloud service without virtualisation is almost inconceivable Make use of efficient scheduling and provisioning methods. Energy consumption can be reduced by means of methods or algorithms (dynamic provisioning algorithms) that select a small collection of active servers so that the other servers can be switched to a low power setting. There are all kinds of heuristics and algorithms for the energy-efficient scheduling of multiple tasks. This is often based on dynamic power management techniques such as DVFS (see for example footnotes 14 and 15 ). This method is only effective if it is worthwhile from the point of view of energy consumption to run servers at a lower utilisation level; in normal situations, efficiency requires the assumption that all servers need to be fully loaded Make ICT resources more effective: optimise distance, utilise energyefficient hardware, other resources Effectiveness can be influenced by making the ICT resources more energy-efficient as well as the other resources such as cooling, accommodation, external networks, and energy transport. Having energy-efficient ICT resources will reduce the energy consumption of the ICT resources as a whole, meaning that it will influence the energy consumption of other supporting resources such as cooling: if less heat is generated because the ICT resources consume less energy, then less cooling will also be necessary overall. However, effectiveness is highly dependent on the location and efficiency of the cooling systems, meaning that the effectiveness improvement may perhaps be less than expected, thus leading to situations in which improving the energy efficiency of ICT resources can even lead to a higher PUE than in the existing situation. 16 In order to prevent this, it is necessary to take a close look at the effectiveness of the cooling systems compared to the ICT resources (see below) Optimise the distance between customer and provider so as to balance network and transport consumption. The effective use of a cloud can be improved by improving the ratio between useful and non-useful energy consumption. What that in fact means is that the energy that is not utilised for ICT resources must be minimised. The energy consumption of the network between the provider and the customer is considered to be non-useful. This means that storage and processing must take place at a location that costs the least energy. This requires both the distance and 13 Energy-Efficient Cloud Computing, A. Berl et al., The Computer Journal, Power-Aware Scheduling of Virtual Machines in DVFS-enabled Clusters, G. von Laszewski et al., Cluster Computing and Workshops, Energy Aware Consolidation for Cloud Computing, S. Srikantaiah et al., Microsoft Research, Micro PUE. The Key to Data Center Energy Savings. A White Paper, R. Hunter and C. Sandberg, Trendpoint Systems.

20 TNO report 20 / 33 the size of the ICT resources at specific locations to be optimised so as to control, for example, the network energy costs and the cost of transporting energy. However, the energy consumption of the network is greatly dependent not only on the distance but also on how the network is used (see 3.2.1); that use is in turn dependent on the application or service that is ultimately constructed on the basis of an IaaS service. This means that it is only the customer for the IaaS service who can decide whether geographical distance is a significant factor in determining the energy consumption Utilise energy-efficient server hardware Utilising energy-efficient server hardware has a direct influence on effectiveness but also on the ratio between the emissions generated during manufacturing/scrapping on the one hand and use on the other. A more energy-efficient server will shift the ratio more towards manufacturing/scrapping. The depreciation period for servers will need to depend not only on economic considerations but also on the point when the total carbon footprint needed to facilitate current and future utilisation is reduced by means of newer, faster, and more energy-efficient models. There are various labels for ICT hardware that to a certain extent guarantee energy efficiency and low environmental impact, for example European TCO Certification 17 and Energy Star. 18 In 2009, the United States Environmental Protection Agency (EPA) produced version 1.0 of the Energy Star specifications for servers. Tests showed that replacing older servers with new Energy Star-labelled servers could reduce energy consumption by 30 to 50%. 19 One limitation of the version 1.0 specifications is that they only give the requirements for small servers with a maximum of four processor sockets. Energy Star expects to bring out specifications for larger servers in the course of Measures or properties that ensure that a server is more energy-efficient include: Incorporation of advanced power management techniques, for example a low power or idling state when the server is hardly being used (or not used at all) and dynamic voltage and frequency scaling (DVFS), which allows the voltage and consequently also the energy consumption and speed to be altered. These techniques combined with effective scheduling methods (see below) bring about a reduction in energy consumption and therefore improved energy efficiency. Make use of blade servers, 20 and enveloping blade chassis, with particular specifications, that take up less space and have greater potential for reducing energy consumption than normal rack servers, for example because the power supply can be shared. Energy Star specifications are also being prepared for storage systems. Using more efficient servers also reduces the amount of cooling required. Saving 1 Watt of energy consumption by a server can produce a saving of 1 to 2 Watts in consumption by the associated cooling system