1 Introduction. carbon footprint, and that can be easily achieved by reducing power consumption as suggested by the law [3].

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1 A Use of Cloud Computing and Chrome OS to Reduce Energy Consumption and E-waste on an Educational Environment Rodrigo Daron Wang, Paulo Roberto Janissek, and Mirelli Zanetti Graduate Program on Environmental Management, Universidade Positivo, Curitiba, Paraná, Brazil Abstract -Environmental concerns, specially related to use of non- renewable sources of energy are the main topics on nowadays business. For many institutions the computers power consumption, even on standby mode, can represent most of the electricity consume. It has been observed that a large number of computers are normally desktops even if most of that are just used for simple tasks, like writing documents. A normal desktop consumes about 130 W, leading to an expressive parcel of total energy consume due to its significance and number at majority of institutions. This work presents a cloud computer alternative as a way to reduce energy consumption. By using a computer configured to use just Internet resources and services, is possible to reduce the power consumption to a level around 15W with similar capabilities. This configuration is possible using a cloud specific operational system, like Chrome OS or Chromium OS, its open source version. Keywords:Cloud Computing, Chrome OS, Environment, Energy-Saving. 1 Introduction Nowadays the use of internet services, like Google Docs, Facebook and YouTube, are growing quite fast and most of the time spend on a computer is on those services [1]. Most of users and applications don t need a big and powerful computer. The use of Cloud Computing operational systems, like Chrome OS[2], may in the near future fill all the user s needs. Google already released some netbook s call Chromebook that runs on Chrome OS, an operational system based entirely on a web browser. This work presents the results from a study to use a similar system as an alternative for the conventional computers of a private university. Due to similarities, the main results could be applied to many institutions out of the educational business. Since a computer that just access the Internet can be less powerful, and consequently consuming less energy, adopting a cloud concept can helps a institution to reduce the carbon footprint. In Sao Paulo, one of the biggest Brazilian city it was already adopted laws to reduce the carbon footprint, and that can be easily achieved by reducing power consumption as suggested by the law [3]. To perform a present study, the power consumption of different operational system was compared. Two operational systems, a cloud-based and a conventional one were installed on different computers. The computers configurations were representative of university environment used to evaluate the cloud computing utilization on an educational institution. Using less powerful computers also has the advantage of having smaller computers, which are going to produce much less electronic waste, also known as E-waste, when the device got obsolete. This work also estimates the e- waste production over a time-line period as computers become obsolete. Based on its characteristics, it can be assumed that cloud computers are good either for a computational point of view as for the environment, but this work also tries to look at the user s point of view. Using a different operational system can be a challenge for users wont to use the conventional systems like Windows and Mac OS. To investigate the user experience, it was created an application that simulates the use of a cloud computing on computers usually accessed by students at the university campus. The user s experience on cloud environment was accessed by a not compulsory answers to a questionnaire automatically presented before the student log off. Since cloud computers use servers to provide the services, their power consumption and the waste generation becomes also a concern. But a server has one benefit as different clients around the world can access it. So its use can easily be optimized, since clients from different time zones can use it. By this arrangement computers become more productive, and being less time on idle state. Another server s advantage is that it can be placed near renewable energy sources, a situation not always possible for institutions or companies that need to be settled near big cities. Also a server can easily be updated or recycled, since it has a higher volume, if compared to personal computer from users around the world.

2 2 Related Work Power consumption can be considered one of the major environmental problems, so the procedures to measure are very important for the study. Bianzino [4] had reported a method to compare different computers and the power consumption of them. His study presents 3 computers, being 2 desktops and 1 notebook, using 3 different operational systems. The power consumption was obtained using the computer s native OS browser to access the web. As results, the authors observed about 70 to 100% of the processor use, with power consumption in the range from 25 to 85W. Souza et al. [5] present a study about the power consumption of notebooks. The project uses a P3 International model P4400 power consumption meter, which is a very useful device to measure the capable of power and energy consumption. The power measurements were captured at every 30 minutes and computers were analyzed in stand- by and active mode. As results, the authors [5] found an average of 17.5W for active mode and a 5,7W for a computer on stand-by mode. They conclude that if the computer were turned off instead of use on stand-by mode there will be a 25% economy on power consumption. 3 Methodology 3.1 Power Consumption comparison between Cloud and conventional computing First a computer was configured to use Chromium OS, the cloud based OS. This computer was a netbook with an Intel Atom N270 with 2GB of ram and Compact Flash card with 8GB for storage. This configuration can be acquired by about $250 dollars in Brazil. As a matter of comparison, the same computer was configured for use the conventional Microsoft OS. The computer was also compared to standard desktops configurations found on the university campus were the present work was done. Table 1 shows the configuration of all the computers used on the test. All the computers were tested on a same environment, for 10-hour and 4repetitions for each test. All the computers were on an active state running a word processor application, and connected to an automated keyboard, that could type at a continuous rate. The word processor application was choose, since this was considered the application used more often on a university, and by all courses and degrees. Using a power consumption meter, connected to the outlet, all the 10-hour test was accounted on each round. The meter used on the test is the P3 International model P4400. After the 4 times round of each computer, the averages of power consumption results were considered. Table 1 Configuration of computers used to compare cloud and conventional system. Cloud Conventional Computers Configured System Notebook Desktop 01 Desktop 02 Processor RAM/Storage Intel Atom 1.6GHz 2Gb/8GB Intel Atom 1.6GHz 2GB/160GB Intel dual core 2,13GHz 4GB/500GB AMD Athlon 2,0GHz 2GB/200GB AMD Phenon X4 2,2GHz 8GB/2x750GB Operational System Chromium OS 3.2 E-Waste generation from computers end of life Another subject addressed by this work was the E- waste generation from computers. The indicator of waste is normally represented by its total mass. The computers on this study were all measured using a precision scale. The E-waste is generated after the computer end of life, when it is considered obsolete. The university where this project was developed has a policy of a 6-year term of computer life cycle, as was reported in [6]. So, if a new computer is added to university today, it will be considered obsolete 6 years later. This lifecycle can be bigger or smaller on other institutions, and it will impact directly on the generation of e-waste. With the historical data of the university it was possible to make a projected scenario for e-waste generation. The scenarios can be used to shows how much e-waste will be produced each in the future, using cloud computing replacements or only the conventional computing system.

3 3.3 User experience on the use of Cloud Computing The user experience is an important aspect of this study, since the computers need to remains functional for the tasks and needs. An application was made to allow the user to use a simulation of a cloud computing OS. This application was running on. After the use of the application the user could answer a questionnaire with questions about his experience using cloud services and cloud OS. The questionnaire users responses indicates the major problems of using cloud computing and also the appropriated places or environment at the university to deploy cloud computing. 3.4 Scenarios about Cloud Computing implementation on a university With the results of the previous parts, was possible to create a scenario, showing a comparison, between the use of cloud computing and the conventional system. The scenario without the use of cloud computing was created based on the historical data from the university, and applying an increasing rate of 5% per year on the total number of computers. Table 2 shows the historical inventory of university computers and the future prediction. The scenario for implement cloud computing was created based on historical data to generate the main results and environmental advantages possible to be obtained with the implementation of cloud computing. It was also took into account for cloud implementation the user experience and the university peculiarities. As a result, it was found that is possible to insert, over the years, new computers using different configurations and a cloud based OS. The data obtained from the user experience, allows deciding which computers on an educational environmental are possible to be replaced by the new systems using, for example, Chrome/Chromium OS. The majority of university computers used at present time have applications (software) that already have similar versions online. As an example, it can be taken the well know Microsoft Office suite, which its similar online application is Google Docs. The best way to add cloud computers in to the university system is by the replacement only the already obsolete computers. This procedure will avoid more computers being discarded, since only the ones that were already destined to be replaced will be changed by the cloud ones. The scenarios were calculated for year time, for number of cloud, conventional and total computers on the university. After the creation of the scenarios, one analyze was done to find out the power consumption, waste generation and costs for implement each scenario.the power consumption was based on the comparison of cloud-based and conventional computers, using the average power consumption of each computer. The waste generation was calculated from mass of computers generated over the years, taken into account the 6-years computer lifetime policy of the university. So, after 6 years a computer is considered obsolete and the waste is generated. The cost of implementation is the sum of the unitary cost of each computer. The cost of the computers was separated in cloud computing and conventional computers. This cost was based on the Brazilian market, in Real s, and price on this paper were also converted to dollars using current rate, even thought this rate may vary in the future. 4 Results The comparison between the average power consumption of the special configured system and the representative computers used in the university is show in Table 2. It can be seen in the Table 2 that the cloud system can be very efficient, with only 8% of power consumption of a desktop. Table 2 Average power consumption from computers tested. Cloud Conventional Computers Configured System Operational System Average power consumption (kwh) Chromium OS Notebook 0.21 Desktop Desktop Even thought the configured system with, consumed almost the same power as the cloud-based system, the system did not run well, with some slower use, as compared to the cloud based or the desktops. The notebook had a great efficiency, but this kind of computer is not normally used on educational institution. The configured system was build to be used as a desktop, with the unit connected to a screen. The second part of the study was the E-waste generation. The measurement of mass from the computers

4 used on the test allowed comparing the e-waste generated when these computers become obsolete. Table 3 show the mass of the computers tested. Those desktops represent computers that are used by the university and the configured system is the alternative implied by this study as a replacement alternative. Another important part of the study was the user experience about the use of cloud computing. The first step was to develop an application to allow a simulation of a cloud-based operational system, like chrome OS by the user.. The figure 1 presents the starting menu for the application installed on some computers. The application allowed the user, before closing the application, to answer some questions about the experience. The questionnaire had 9 questions and on table 4 are showed the 3 more relevant. These questions allowed the study to find out how the users were reacting to the system. Table 5 shows the percentages of the answers. Those answers allowed the study to find how many computers were easily replaceable to the new system. Table 3 Mass of the different computers tested. Computer Operational System Mass (kg/lbs.) Some computers were considered not suitable to be replaced, mainly because they use specific applications like equipment controlling and software for design and engineering courses that doesn t have online alternatives. This is a expected situation for many institution, but even that a great number of computers are for non-specific use, as for research and normal students tasks that are possible to be replaced.. By combining the previously results it was possible to create scenarios for implementation of cloud computer on a university. The inventory database, used and a future projection with 5% grow per year is showed on Figure 2. Table 4 Questions done to access the users experience on cloud computing use. Question 1. How do you rate your experience using cloud computing? 2. How do you rate the idea of using cloud computing? 3. Do you think is possible to use a cloud-based only computer? Cloud Conventional Configured System Chromium OS 0.9/ /2.2 Notebook 1.8/3.9 Desktop /22 Desktop /24 Table 5: The percentages of answers given to the questionnaire by the students Question Alternatives Responses (%) Very Good Good Bad Very Bad Very Good Good Bad Very Bad Yes No With the inventory data, this study suggests a replacement plan, by changing new computers to ones using cloud-based operating system. It was assumed considering that not all computers can be replaced, since some computers needed to remain using the conventional system. Figure 3 shows the number of computers for each system over the years. Figure 1 Screenshot of the application dedicated to simulate a cloud environment use.

5 Figure 2 Graphic with the inventory and the future predictions for university computers number From the scenario showed on Figure 3 were created some graphics comparing the power consumption and the e- waste generation over the years, to compare and find out the benefits and disadvantages of cloud system implementation. Figure 4 shows the difference on the power consumption between the new scenario and the control one (with only a normal system).. By comparing the two systems it can be seem that the cloud-based system uses almost 50% less energy demand. Figure 4 Comparison between the power consumption from control (conventional system) and cloud-based system implementation The differences for the two comparative scenarios on discarded computers subject takes time to shows up, because the 6 years time to computers become obsolete. On the graphic is possible to see that the mass differences will be noticed only after By that time, the mass of discarded computers starts to decrease due to the use of lightweight computer, with less processor power. Figure 6 Comparison of the mass of discarded computers over the years. Figure 3 Number of computers for each system on the suggested scenario. The figure 5 presents the comparison of the mass of E- waste that would be generated from computers discarded over the years. It should be emphasizes here a 6 year university policy for computer s lifespan and that the computer configured to use the cloud-based OS has significant lower mass then a normal desktop. 5 Conclusions The use of cloud computing on a university or any educational institution seems to be a plausible idea. It must be taken into account that not all computers can be replaced, at least by the moment, mainly because there is not enough Internet services for all the tasks needed. Even that, there are many places where the replacement can be done with great advantage, specially looking on a environmental perspective. The power consumption and the generation of e-waste are becoming an increasing concern all over the world.

6 This study shows that is feasible to use cloud computing scenario with benefits about 50% on energy economy and producing less e-waste over obsolete computers. There is still some study to be done to reduce server power consumption and e-waste generation, but as stated before, the centralization use of the server allows the use of renewable sources of energy and recycling alternatives can easily be applied. 6 References [1] Voas,J.; Zhang, J., "Cloud Computing: New Wine or Just a New Bottle?," IT Professional, pp , 2009 [2] GOOGLE, Chromebooks, 2011 available at < accessed at [3] PMCMSP - LEI No Política de Mudança do Clima no Município de São Paulo, São Paulo, [4] BIANZINO, A.; ROSSI, R.; RAJU,A., Greening the Internet surf: Experimental measurements of Web powerconsumption, Département Informatique et Réseaux / Network and Computer Science department (INFRES), Télécom ParisTech, IT Professional, Special Issue on Green IT13, 1, 2011 pp [5] SOUZA, A; SCHEMBECK, L; ANDRADE,M., Estudo sobre consumo de energia em notebook e gastos decorrentes, Revista Ciências do Ambiente On-Line, volume 7, número 1, p , 2011 [6] ZANETTI, M. A.Avaliação do Ciclo de Vida dos Computadores e Prolongamento da Vida útil como Alternativa Ambiental. Master s Thesis, Universidade Positivo, Available at < up.com.br/secao/185/teses-e-dissertacoes.aspx> [7] WANG, R. Potencialidades e limitações da Computação em Nuvem: Estudo de caso com ênfase ambiental. Master s Thesis, Universidade Positivo Avaliable at < and < es.aspx>