July 2011
Article
AutomatedBuildings.com
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T
he phrase “automated buildings” conjures up images of sophisticated
monitoring and control systems working around the clock to balance
occupant comfort and energy consumption and to keep mechanical and
lighting systems functioning optimally. Building automation systems
(BAS) can improve building performance by 20%. But there is a key
aspect of the building’s performance that is typically missing from
this picture, an element that typically comprises one quarter to one third of a
commercial building’s electricity consumption: plug-loads.
While the energy efficiency of individual appliances and electronic
devices has improved significantly over the past 30 years, the number
of devices in homes and commercial offices has more than tripled in the
same time. Standby power from plugged-in equipment accounts for more
than 100 billion kilowatt hours of annual U.S. electricity consumption
and more than $10 billion in annual energy costs, and these numbers
will keep growing if we do not collectively take control of the
situation.
In a typical office environment, there are a myriad of plugged-in
devices – from printers to computers to water coolers and coffee makers
– that consume energy 24 hours a day and 7 days a week, even though
offices are only occupied for about one-third of the time. So even
after employees have left for the evening or weekend, most equipment
sits idle, using power and wasting money and electricity.
Manually tackling plug-load energy waste can seem challenging since it
occurs throughout the building at each individual plug. The good news
is that there are now technological options that help simplify and
automate these savings.
Quantifying the Waste
The first step in solving the plug-load energy waste problem is to
quantify the scope of the waste and then identify the biggest energy
offenders. ThinkEco, Inc., a New York-based company focused on
plug-load energy management solutions, launched its Eco Empowered
Initiative in 2010 to help businesses do just this. The
initiative included a diverse set of participants – 112 sites across 82
organizations ranging from schools to offices to financial institutions
– and monitored over 460 electric devices.
To monitor energy consumption, ThinkEco used its patent-pending modlet®
and proprietary web application. The modlet (for modern outlet), plugs
directly into existing outlets and monitors the real-time energy
consumed by plugged-in equipment. This data is then wirelessly
communicated to the user’s computer and viewed through the ThinkEco
Power Manager, instantly shedding light on the energy waste that was
once hidden.
The results of the Initiative showed that printers, multifunction
devices and desktop computers waste the most energy in the office
environment. Taking printers as an example, the source of energy
waste is multi-fold, which may seem surprising given that most printers
are equipped with a low power-consuming sleep mode. To begin with, the
Initiative revealed that sleep power consumption is not
one-size-fits-all – in fact, it ranges from 3 – 100 watts depending on
the size, functionality and brand of printer. Monitoring also revealed
that printers don’t always behave as they should - low toner, a paper
jam or some other warning can prevent a printer from sleeping for many
days. Finally, many printers are simply underutilized: over 40% of
printers in the Eco Empowered Initiative performed just 5 – 15 print
jobs per day, and 30% performed less than 5 print jobs per day.
Energy waste is not limited to traditional office equipment
either. Vending machines, coffee makers and water dispensers are
also major sources of energy waste in the break room. To quench
employee’s thirst, these beverage machines run cooling or heating
cycles 24 hours a day to constantly keep beverages cold or hot. Cold
beverage vending machines use the most energy of all plugged-in
equipment in a typical office – using 128 – 350 watts at all times and
costing up to $450 per year. Single brew coffee makers are typically
well-utilized during the morning and then again in the afternoon, but
consume an average of 52 watts at all times to keep water hot just in
case someone wants another cup. Hot and cold water dispensers work
double duty, consuming 64 watts on average to maintain water at two
different temperatures.
Curbing the Waste
After uncovering these varied sources of energy waste in the office,
users in the Eco Empowered Initiative created schedules that allowed
the modlets to automatically turn their electronic devices on or off.
From pre-programmed to custom schedules, the modlet system allowed both
large and small-scale participants to save energy in a set-it and
forget-it manner.
By utilizing the modlet system, participants saved between 6 – 10% on
their electricity bills. On an appliance level, this translated into 35
– 80% per device. Participants typically scheduled their devices
to turn off for 12 hours on each week night and for the whole 48 hour
period during the weekend.
Since modlet scheduling automatically turns devices back on in the
morning before employees arrive, participating companies were able to
save money without the employees even knowing that their printer or
favorite beverage machine was turned off for the night.
Helping Building Occupants in More Ways Than One
The advantages of a complete plug-load management system go beyond
energy monitoring and control. Since plug-loads are so localized,
employees can monitor their personal energy consumption and become an
active partner in reducing it. In this way, the modlet system has been
used by corporations to engage individual employees in corporate social
responsibility efforts.
Plug-load management systems like the modlet also help in equipment
purchasing decisions for facilities managers. The power consumption
profiles for each device help managers compare the efficiency of
different printers, for example. In addition, the modlet provides
insight into how frequently the equipment is used, which can help
managers determine the optimal number and distribution of devices
within an office.
In summary, plug-load management systems not only complement
traditional BAS to provide total building energy monitoring and
control, but provide other value-added benefits to tenants while
boosting overall building energy efficiency. Together, lights,
HVAC systems and now individual electronic devices can be managed
optimally, painting a brighter picture for sustainable building
automation.
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