Laptop Or Desktop? An Estimation Of Potential Energy Savings In Coba Uniten

Abstract

Desktop computers have been identified as one the biggest source of energy usage in a building based on plug load. It has also been established that laptop computers, on the other hand used much less energy due to its efficient design. There are 107 academicians at the College of Business Management and Accounting, Universiti Tenaga Nasional who all provided desktop computers to work on. As such, it is inferred that those desktop computers use a lot of energy, incurring high energy bill for the university in the process. This paper estimated the energy used by the desktop computer of said academicians as well as the energy usage of its laptop equivalent. The potential energy savings, should a migration to laptop based computing environment happened, is then highlighted. Desktop computer of COBA academicians is estimated to use 43,527 kWh of energy annually which is equivalent to RM15,887.57 in energy bill. Laptop computer, on the other hand, is estimated to only use 9265 kWh of energy annually or RM3381.85 in energy bill. All in all, this potentially translates into 34,262 kWh of energy savings or the equivalent of RM12,505.72 in energy bill, a 79% reduction.

Keywords: Energy savingenergy efficiencydesktoplaptopcomputerUNITEN

Introduction

In an era where energy efficiency is a buzzword that is mentioned in the same breath of renewable energy, low power appliances such as computers are now seen as a major energy use. A study by New Building (2012) found that plug loads can account for up to 50% of building’s electricity usage. Delving deeper into this usage, a monitoring study conducted by Moorefield et al. (2011) indicated that computers accounted for 66% of small energy consumption in offices. This was confirmed by Gandhi and Brager (2016) who found that desktop computers consume the most energy per person. A assessment of research for small scale power demand and consumption revealed that no studies have ever been undertaken to evaluate the energy savings that could be made possible by switching from desktop to laptop in a higher learning and research institute, much less a higher learning institute that claims a forte in the area of energy. As such, there is a great potential for energy savings in such an institution.

The focus of this paper would be on the energy usage of computers. According to Menezes et al. (2013), computers are observed to be the single biggest source of energy usage. As observed in Table 01 , the same author noted that in the case of desktop computers, the power usage ranges between 64 to 169 Watts. These figures are in line with modern desktop computers specification. As for laptop, there is a stark difference in energy usage. Menezes et al. (2014) noted that laptop computers only consumed between 18-41 Watts of power during active usage. Since energy efficiency is a key issue for laptops, they have lower energy usage.

Problem Statement

According to Bray (2006), usage of laptop computers presents an opportunity for energy savings in an office environment. Speaking at a CM Summit, Meeker, Devitt, Wu (2010) announced that laptop shipment figures are projected to surpass that of desktop. This is indicative of a trend in the computing environment to switch from desktop to laptop. As such, conversion or migration from desktop based to laptop based computing environment would result in greater energy savings which would then lead to better energy efficiency. This is even more so in the age of the renewable energy where intermittency issue with non dispatchable power demands greater energy efficiency from end users as intermittent renewable energy might not be able to provide sufficient energy to fulfil demand during peak working period.

As stated earlier, there is a lack of studies on the potential energy savings resulting from the conversion from a desktop based computing to laptop based computing, especially in a higher learning institute environment. Most studies focused on the aspect of energy efficiency of office equipment by means of benchmarking; also on the energy saving potential through power management. The best way to demonstrate the potential energy saving from this conversion is by an estimation exercise in a higher learning institute which specializes in the field of energy studies.

Research Questions

Purpose of the Study

The aim of this paper is to provide an estimation of potential energy savings that could be achieved by migrating from desktop based computing environment to a laptop based, from the usage of academicians based in College of Business Management and Accounting (COBA), Universiti Tenaga Nasional (UNITEN). This author observed that employees of the parent company of UNITEN, TNB, were equipped with laptops. As such, this paper intends to gauge the energy savings should UNITEN were to follow the policy of its parent company. This paper is exploratory and desktop in nature with its output meant to guide follow up and more detailed studies that could recommend policy changes.

Research Methods

The estimations in this paper are made based on technical data several secondary sources including guidelines from Sustainable Energy Development Authority Malaysia (SEDA Malaysia) and Hewlett-Packard Development Company (HP) as from Menezes et. al (2014) findings. Data from HP was used in lieu of direct measurement since from the observation of this author, most if not all desktop computers used in COBA are of the HP brand. Data from SEDA and literature are used to estimate usage period as well as for power consumption of laptop computer.

Findings

The findings of this paper is divided into two parts; the first is an estimation of power usage of desktop computers in use by COBA academicians while the second part is an estimation of power usage of laptop equivalent. Next, the potential energy savings in terms of kWh as well as in RM terms from the usage of laptops is then presented.

Conclusion

Academicians at COBA, UNITEN were each provided a desktop computer as part of their office equipment. The desktop computer in question is of the HP brand with LCD monitor. It has been proven in the literature that desktop computers are one of the biggest source of energy usage in an office environment. This finding is further supported by HP’s own whitepaper and is corroborated by this author’s observation on his own desktop computer which has a 240 Watts power rating (excluding the monitor).

This study aims to provide an estimation of the energy savings potential should desktop computers were migrated to laptops. Two research questions were proposed which were the estimated power consumption of HP desktops used by COBA academicians as well as its laptop equivalent and the estimated energy savings from migration to laptops. Based on secondary data and several assumptions, the two research questions have been answered thus fulfilling the purpose of this study.

It is estimated that COBA academicians, on aggregate, used 43,527 kWh of energy annually through their desktop computers, raking up RM15, 887.57 in electricity bill that needs to be footed by the university. In contrast, should COBA academicians were to be provided with laptops, on aggregate, the annual energy consumption is estimated to be only 9,265 kWh or RM3381.85 in electricity bill. Therefore, the potential energy saving is 34,262 kWh or RM12,505.72 which is a 79% reduction. The author believes that this energy saving potential is a testament of interdisciplinary sustainability perspective and augurs well with UNITEN’s Smart UniverCity framework.

References

1. Bray, M. (2006). Review of Computer Energy Consumption and Potential Savings. Dragon Systems Software Limited.
2. Gandhi, P., Brager, Gail S. (2016). Commercial office plug load energy consumption trends and the role of occupant behaviour. Energy and Buildings, Volume 125, Pages 1-8
3. Hewlett-Packard Development Company. (2008). HP Workstation Power Usage Estimator. Retrieved from h20331.ww2.hp.com/Hpsub/downloads/HP_Workstation_PowerUsageEstimator.pdf
4. Meeker, M., Devitt, S., Wu, L. (2010). Internet Trends. CM Summit. Morgan Stanley Research, New York City.
5. Menezes, A.C., Cripps, A., Buswell, R.A., Bouchlaghem, D. (2013). Benchmarking small power energy consumption in office buildings in the United Kingdom: a review of data. CIBSE Guide for Building Services Engineering Research & Technology, 34 (1), pp. 73-86
6. Menezes, A.C., Cripps, A., Buswell, R.A., Wright, J., Bouchlaghem, D. (2014). Estimating the energy consumption and power demand of small power equipment in office buildings. Energy and Buildings, Volume 75, Pages 199-209.
7. Moorefield, L., Frazer, B., Bendt, P. (2011). Office Plug Load Field Monitoring Report. Ecos Consulting, California.
8. NBI. (2012). Plug Load Best Practice Guide – Managing Your Office Equipment Plug Load.
9. Sustainable Energy Development Authority Malaysia (2017). Perbandingan Penjimatan Tenaga di Pejabat. Putrajaya