1. INTRODUCTION
More and more small and medium size companies worldwide have opened
their eyes to the potential benefits of "Going Green."
However, what does it mean to go green for companies and their IT
organizations? Green IT/Green computing can be defined as "the
study and practice of designing, manufacturing, using, and disposing of
computers, servers, and associated subsystems--such as monitors,
printers, storage devices, and networking and communications
systems--efficiently and effectively with minimal or no impact on the
environment." (Murugesan, 2008). Knowing what is involved, it is
easy to become overwhelmed with ideas when presented with such a broad
spectrum of green initiatives. Throughout this paper, we will focus on
the benefits of green computing for those organizations with less than
500 employees.
A company that utilizes ENERGY STAR rated LCD monitors with sleep
settings activated, over the course of four years, saves an estimated
$42,445 versus a company that is still utilizing conventional LCD
monitors (http://www.sba.gov/content/energy-saving-calculators-energy-star). In addition to the monetary savings, green computing has an
immediate and lasting positive impact on our environment. Green
computing lessons our reliance on the earth's natural resources and
it also has the ability to reduce dangerous green house carbon
emissions. With a well thought out implementation plan, it is possible
to take gradual steps towards an eco-friendly, functional business
model. It is important however to realize, that a company new to green
computing should plan on implementing ideas in stages and measure
results over time. This paper will cover methods and recommendations for
green computing and the appropriate metrics to measure progress.
2. DATA CENTER ENVIRONMENTAL DESIGN CONSIDERATIONS
There are many design alternatives when considering existing data
center or planning a new one. One of the largest cost concerns for any
data center is energy consumption. These concerns are generated from the
electricity necessary to power hardware which includes storage devices
and servers as well as the energy utilized to keep the data center at a
consistent temperature. Knowing these concerns leads to the first data
center design consideration which is energy efficient methods of cooling
the data center. A good place to start is a floor plan that will allow
for greater air flow through a data center.
2.1 Hot Aisle/Cold Aisle Data Center Layout
This particular layout requires servers to be set on a raised floor
with perforated floor tiles. It is common for a server to be designed
with the intake on the front of the unit. This design requires placing
rows of cabinets so that the fronts or intakes faced each other thus
creating the cold aisle. The cold aisle is also where perforated floor
tiles are placed. By placing the exhaust end of the cabinets towards
each other a hot aisle has been created. At the end of hot aisles, floor
cooling units would be utilized to force cooler air back through the
perforated floor thus reducing the amount of preheated air that is being
introduced to the server.
2.2 The Containment System
The hot aisle/cold aisle design could be improved using containment
curtains. The containment curtains allow for maximization of the cold
aisle by containing the existing cool air and minimizing the amount of
preheated air that enters the cold aisle. One example of a cold air
containment system is the AirBlock[TM] containment systems. This
containment system set up is noted as having the potential to save
energy on air conditioning by as much as 15%.
(http://www.dataclean.com/data-center-strip-curtains.html). For a
successful hot aisle/cold aisle design it is essential to consider a
front-to-back air flow pattern.
2.3 Cable Management
In conjunction with the hot aisle/cold aisle design, cable
management is a second design consideration that may help reduce energy
costs. According to the U.S Department of Energy (Best Practices Guide
for Energy-Efficient Data Center Design, 2011) cable congestion in
raised-floor plenums can sharply reduce the total airflow as well as
degrade the airflow distribution through the perforated floor tiles. In
addition to the issues with raised-floor plenums, it is important to
realize that cables act as insulation. If left to hang loosely over the
back of the rack the cables will essentially be trapping the hot air
exhaust within the unit. This will require greater energy to cool the
data center resulting in higher energy costs. Therefore, whenever
possible cables should be routed through the hot aisle. The goal is to
minimize the amount of obstructions that interfere with the cool air
flow through the perforated floor tiles in the cold aisle.
To facilitate this process, there are several cable containment
options available today. If an organization is considering new server
cabinets then it is recommended to purchase a unit that provides a built
in cable management system. There are also companies such as Panduit
that offer cable management rack systems that may retrofit to current
cabinets. Another method for aiding in the reduction of cable congestion
is to bring the necessary power supplies closer to the unit. This will
reduce the amount of cable running through the data center.
2.4 Economizer
A third energy saving design consideration is the implementation of
an economizer. There are two data center economizer options. The first
option is an air-side economizer. With an air-side economizer, outside
air is brought into the data center and distributed throughout servers
via sensors and ducts. Unlike a traditional data center cooling set up
where air is re-circulated and cooled, an air-side economizer expels the
warm air outside that can be used to heat office spaces. In the event
the outside air temperature is too hot or too cold, the economizer is
able to heat or cool the air as necessary to maintain the data center
inlet temperatures. In a 2008 study conducted by Intel IT department,
the use of an air-side economizer would result in an estimated annual
cost reduction of approximately $143,000 for a small 500-KW data center,
based on electricity costs of 0.08 per KWH.
(http://www.intel.com/it/pdf/Reducing Data Center Cost with an Air
Economizer.pdf)
If considering the implementation of an air-side economizer it is
important to investigate the appropriate means for monitoring and
controlling humidity levels and air particle filtration.
The second economizer option to consider is a water-side
economizer. With a water-side economizer there are no major changes to
internal area of the data center. A "water-side economizer uses the
evaporative cooling capacity of a cooling tower to produce chilled water
that can be used instead of the chiller during the winter months"
(http://www.energystar.gov/index.cfm?c=power mgt.datacenter
efficiency economizer waterside).
When a data center's warm water is routed to the water-side
economizer, it meets the cooled water and the heat is then evaporated
through a dry cooler or evaporative tower. Water-side economizers are
recommended for climates that experience temperatures at or below
55[degrees]F for at least 3,000 hours a year and may be best suited for
companies that are currently equipped with water or air-cooled chilled
water systems. One immediate benefit to the water-side economizer is the
absence of outside elements such as humidity and air particles being
introduced into the data center.
3. DATA CENTER HARDWARE CONSOLIDATION
Hardware plays a major role in a data center energy use and heat
generation. One hardware consideration is to make certain that the
center is utilizing existing equipment to its potential. One common
issue in a data center is not utilizing existing servers to their
potential. For example, if an organization is running ten servers at
utilization rates of 15% there is a significant waste of energy compared
to other servers running at 85% capacity. One option to address low
server utilization is server virtualization.
3.1 Server Virtualization
Virtualization is a means of utilizing multiple independent virtual
operating systems on a single physical server component. By putting
virtualized server operations into one physical component the level of
CPU utilization will be increased. This process will therefore reduce
the number of server required and amount of physical space that is
occupied as well as utilizing a fraction of the energy to operate them.
Basically, a company will achieve similar results from a virtualized
server as they would with several independent servers. It saves money by
reducing energy consumption, the need for additional employee operators,
and it lowers cooling costs. All of these factors equate to lessoning a
company's carbon footprint.
3.2 Cloud Storage Technology
A second option to consider when planning energy reducing practices
in an organization is to use cloud storage technology. Cloud storage is
the means of storing data on a network of online servers versus storing
data on a dedicated storage server. There are several benefits to cloud
storage. First, the organization only pays for what it uses. This
alleviates the concern of scalability. Second, cloud storage reduces the
amount of hardware in a data center therefore reducing energy costs. One
final benefit of cloud storage is information accessibility. With cloud
storage it is possible to retrieve data from remote locations where
there is an Internet connection.
A common concern with cloud storage is data security. Any time data
are transmitted over the Internet there is risk of having data
compromised by hackers and other computer crimes. This is a concern that
each company must address and decide if the risk reward ratio provides a
comfort level that permits the use of cloud storage. One additional
storage consideration is the implementation of thin provisioning. This
practice provides storage to applications from a common pool that is
used on an as needed basis. Like the previous examples, utilizing thin
provisioning will reduce the amount of wasted storage and the need for
additional storage devices. This will decrease data center energy
consumption. According to Dell, if a company was to utilize Dell's
thin provisioning "Dynamic Capacity[TM]" software, a company
could reduce the capacity needed to store existing data up to 40%.
(http://www.compellent.com/Products/Software/Thin-Provisioning.aspx).
One final consolidation consideration is with a server's
supplied power supply. Those data centers that are not utilizing a power
supply that was configured specifically to their data center design;
there is a good chance that a lot of energy is wasted. With available
technology today it is possible to run a server power supply with a 95%
efficiency rating. This technology results in considerable savings.
Using higher efficiency power supplies will have a direct impact on a
data center's energy consumption. The Best Practices Guide for
Energy-Efficient Data Center Design report states that at $0.12/kWh,
savings of $2,000 to $6,000 per year per rack (10 kW to 25 kW,
respectively) are possible just from improving the power supply
efficiency from 75% to 85%.
4. GOING GREEN IN THE OFFICE
For the purpose of this section of the paper, the focus will be on
three main areas of opportunity for making an organization's office
space more environmentally friendly. Going green begins with the paper
supply. According the Environmental Protection Agency (EPA), the average
office worker in the US uses 10,000 sheets of copy paper each year
(http://www.epa.gov/osw/conserve/materials/paper/faqs.htm#offices).
10,000 sheets of paper equal two cases of copy paper per employee per
year. The average cost of a case of paper at local supply stores is over
$40. This translates to over $40,000 annual paper cost for an
organization with 500 employees. This dollar amount does not include the
cost of printer, printer maintenance, ink, and paper disposal. There are
tremendous savings to be made by implementing paperless initiatives. The
goal is to keep any documentation that started out in an electronic
format in an electronic format as long as possible. If a documents start
with a physical copy, that is to be viewed by several individuals, it is
recommended that the document be scanned to generate a PDF file that can
be sent via email or accessed from a cloud storage system. For offices
that provide paper invoices, it may be prudent to consider offering
customers a paperless option. A paperless billing option will reduce the
amount of energy a company spends on generating, packing and shipping
invoices and will offer the convenience of an online bill paying option
for clients.
One important thought to keep in mind when trying to implement
paperless initiatives is that it is imperative that the organization
have buy-in from the top level executives to the lower level staff.
There must also be awareness that the paperless process takes time and
patience. It will not happen overnight. Next, is utilizing ENERGY STAR
rated monitors and PCs. As stated previously, a company that utilizes
500 ENERGY STAR rated LCD monitors with sleep settings activated saves
an estimated $42,445 over the course of four years versus a company that
is still utilizing conventional LCD monitors (Van Geet, 2011). Moreover,
utilizing ENERGY STAR rated PC's will result an additional savings
of over $28,000 over four year period (Van Geet, 2011). This will save a
small organization an estimated $18,000 in energy cost per year. In
addition to monetary savings, the environmental savings equates to a CO2
reduction of 1,112,923 pounds or the planting of 115.76 acres of forest.
In addition to operating a company with ENERGY STAR rated workstations,
it is important to stress to employees the importance of turning off
their workstations when not in use. The use of power strips will further
reduce energy consumption.
In addition to the paperless initiatives and the use of ENERGY STAR
rated PCs and monitors, simple changes such as installing switch plate
occupancy sensors in an office that only turns on lights on when someone
is in the room is another effective means of lowering energy costs. To
further maximize savings on office lighting it is recommended that
ENERGY STAR qualified compact fluorescent lamps (CFLS) are installed in
any feasible location. CFLS cost about 75% less to operate, and last
about 10 times longer.
(http://www.sba.gov/content/energy-efficiency).
The 2009 federal stimulus bill contained approximately $50 billion
in funding to promote clean energy. Among the incentives are tax
deductions for businesses that can cut their building's energy
consumption by 50 percent.
5. SELECTING METRICS
In order for any green initiative to be proven successful it is
important to monitor progress. A company should document the baseline
energy consumption then monitor progress during and after initiatives.
This can be accomplished by participating in qualitative and
quantitative analysis and by performing periodic audits on the
equipment.
One example of a quantitative analysis would be to conduct a Usage
Profile review. This review would allow companies to look at the ebb and
flow of power consumption. A second recommendation would be to conduct
performance comparisons with companies of comparable size and service.
It is always good practice to see where an organization stand in the
effectiveness of green initiatives within their industry. It is also
recommended that companies take the opportunity to gather feedback from
employees. Often employees are the individuals that are directly
impacted by the green initiatives. To keep green initiatives alive and
effective, continue to solicit feedback and ideas from employees to
further their buy in to your efforts.
5.1 Power Usage Effectiveness and Data Center Efficiency
Two metrics have recently been introduced that help measure data
center efficiency: Power Usage Effectiveness (PUE) and Data Center
Efficiency (DCE). PUE is defined as:
PUE = Total facility Power / IT Equipment Power
Whereas DCE is defined as:
DCE = IT Equipment Power / Total Facility Power
These metrics can be used to illustrate how energy is being used in
a data center. For example, a PUE 4.0 means that the data center demand
is three times greater than the energy needed to power IT equipment.
Moreover, these numbers can be used to calculate how much power a new
piece of equipment will need from the power grid. For instance, if a new
server demands 250 watts of power to run, and that multiplier is 4.0, it
means that the utility grid will need to deliver 1000 watts to run this
server. DCE is probably even more useful. Using the same example of a
4.0 PUE, the DCE equivalent is .25. Therefore, IT equipment consumes 25
percent of the power in the data center and 75 percent of power is used
for cooling systems, lights, etc.
Total facility power is the power as it is measured at the meter
for a data center. IT equipment power is defined as the power needed to
manage, process, store, or route data within the data center. The PUE
can range from 1.0 to infinity. A lower PUE means that most power
consumption is for running IT equipment. In the best case, a PUE
reaching 1.0 would show 100 percent effectiveness of data center's
power usage . Currently, most data centers are in 3.0 and higher range,
but properly designed data center can achive a PUE of 1.6.
6. RECYCLING
Once computing devices such as PC's, monitors and printers
reach the end of their serviceable lifespan, companies are left with the
daunting task of how to dispose of the equipment. Computers contain
several hazardous materials like lead, mercury cadmium and PVC that pose
risks to the environment. One option for PC disposal is to utilize an
online auction or classifieds site to re-sale old equipment. Depending
on the amount of equipment and what type of secure information exists on
the hard drive, this may not be a realistic means for a company to
generate extra money. A second option is to participate in recycling
program like the Dell Reconnect program.
The Reconnect program is a partnership with Goodwill Industries.
The Reconnect program will take almost any computer or computer related
piece of equipment and recycle it for free. This particular option has
several benefits. It is a free service, hazardous material do not end up
in landfills and the organization is supporting a respected
not-for-profit organization in Goodwill Industries. If the Reconnect
program is not available in your area, you can visit the Earth 911
website which will provide resources and recommendations for community
centered recycling programs.
7. CONCLUSION
The size of an organization should not dictate the efforts to
implement green initiatives. It is possible for an organization to
realize great energy and cost savings by implementing data center
designs like the hot aisle/cold aisle configuration or by utilizing
ENERGY STAR rated PCs, monitors, and light fixtures. When setting up
green initiatives it is important to remember to set specific,
measurable, attainable, realistic, and time bound (SMART) goals. This
will aid in maintaining the company focus. With an organized plan that
is accepted by all parties in the organization, a company can find
success with green initiatives. It will be important to monitor and
analyze progress and to participate in periodic reviews of the green
initiatives to insure that they are on track with the original
organizational plan. Periodic reviews will also provide an opportunity
to recognize areas of actions. In every new organizational effort it is
possible to experience resistance, however, it is important to maintain
the perspective that every effort helps in reducing negative impact on
the environment and reducing energy consumption and costs.
REFERENCES:
http://www.compellent.com/Products/Software/Thin-Provisioning.aspx
http://www.dataclean.com/data-center-strip-curtains.html
http://www.energystar.gov/index.cfm?c=power mgt.datacenter
efficiency economizer waterside
http://www.epa.gov/osw/conserve/materials/paper/faqs.htm#offices
http://www.intel.com/it/pdf/Reducing Data Center Cost with an Air
Economizer.pdf
Murugesan, S. (2008). Harnessing Green IT: Principles and
Practices. Retrieved March 21, 2011, from
http://en.wikipedia.org/wiki/Green computing.
http://www.sba.gov/content/energy-efficiency
http://www.sba.gov/content/energy-saving-calculators-energy-star
Van Geet, Otto. (2011). Best Practices Guide for Energy Efficient
Data Center Design. Retrieved March 21, 2011.
U. S. Federal Government Increases Commitment to EPEAT Green
Computing. Retrieved Apr. 11, 2011 from
http://digitalcommunities.com/articles/US-Federal
-Government-Increases-Commitment-to.html
In Business Energy Waste. Retrieved Apr. 13, 2011, from
http://www.paystolivegreen.com/2009/05/business-energy-waste/
Green Computing. Wikipedia-Online Encyclopedia. Retrieved Apr. 11,
2011 from http://en.wikipedia.org/wiki/Green computing
Green IT and Cloud Computing 2.0 Summit 2011--Earth Day Celebration
2011--Green Technology Style. Retrieved Apr. 12, 2011 from
http://www.prweb.com/releases/2011/04/prweb5240124.htm
Advantages & Disadvantages of Corporations Going Green.
Retrieved Feb. 18, 2011 from http://www.ehow.com/facts 5032914
advantages-disadvantages -corporations-going-green.html
Gingichashvili, S. Green Computing. Retrieved Apr. 11, 2011 from
http://thefutureofthings.com/articles/1003/green-computing.html
IBM Green Computing. Retrieved Apr. 14, 2011 from
http://www-01.ibm.com/software/solutions/green/
In Reducing Waste in the Workplace. Retrieved Feb. 18, 2011, from
http://156.98.19.245/workplace/index.html
Liu, S., IT Professional in 2011. ProQuest. Retrieved Apr 14, 2011,
from http://libdb.sjfc.edu:2500/login?url=http://proquest.umi.com/
pqdweb?did=2251732111&sid=4&Fmt=2&clie
ntId=4463&RQT=309&VName=PQD
Smith, K. Green Computing with Dell. Retrieved Apr. 15, 2011 from
http://www.ecoelectrons.com/greenpower-blog/bid/39819/
Green-Computing-with-Dell
What Are the Disadvantages of Going Green? Retrieved Feb. 18, 2011
from http://www.livestrong.com/article/137345-what-are-disadvantages-going -green/
Farrokh Mamaghani, St. John Fisher College, Rochester, New York,
USA