A Market Study

1
LCD vs CRT Energy Consumption

• A Market Study
• Prepared for
• Dell Computer
• by
• Mark Fihn
• DisplaySearch
• October 29, 2001

2
What Others Are Saying
3
Photon Dynamics Presents to White House
Photon Dynamics demonstrated to President Bush
on two separate occasions regarding the
difference in energy consumption between a 17.0
LCD monitor versus a 19.0 CRT monitor by
attaching power meters displaying watt usage.
The difference in power consumption was dramatic,
73 watts. LCDs typically use approximately 30 of
the power of similar CRTs. "Research shows that
LCDs use about 74 percent less electricity and
space, than their CRT predecessors, while
reducing eye-strain and heat load," said
Sollitto. "With more than 50 million CRTs in
California, the state could save up to 1 billion
a year or almost 5 billion kilowatt hours of its
total electricity use if only half of the CRTs
were replaced with LCDs," he added.
4
State of California Analysis
Supply - California has the ability to
generate 55.5 billion watts of power and can
import another eight million watts per day.
Actual capacity appears to be around 45 billion
watts due to transmission losses and some plants
not fully operational. For more info, see
www.cpuc.ca.gov/published/report/GOV_REPORT.htm.
Demand - Peak energy demand in California in
the winter is 45.5 billion watts while summer
2000 demand reached 53 billion watts. For more
information on California's energy demand, see
www.energy.ca.gov/electricity/commission_demand_fo
recast.htm. Population - 33.145 million peo
ple according to the 1999 census.
Number of CRTs per Person Estimated at
1.5. Includes TVs monitors, public displays,
ATMs, etc., so that the number of CRTs in
California is estimated at 49.7 million.
Watts per CRT - Estimated at 115. Depends on
size, brightness, etc. Watts per LCD Monitor
- Estimated at 35. Also depends on size,
brightness, LCD mode, etc. Watts Consumed By
CRTs - 5.72 billion Watts. Watts Consumed i
f All CRTs Replaced By LCDs - 1.74 billion Watts
Power Savings from Migrating to LCDs -3.98
billion Watts. The four billion Watt reduction
would solve many of California's energy problems
by reducing power consumption by 9. It would
avoid blackouts and Stage 1, 2 and 3 alerts,
which are defined as statewide power reserves
falling below 7, 5 and 1.5. The four billion
Watts is approximately equal to the combined
output of all nuclear power plants in California
and could power four million homes.
Price per kW/hr - 0.10 - 0.30 depending on
time, type, etc. Photon Dynamics assumes 0.12 on
average. Price per W/hr would then be 0.00012.
Cost Savings Per Day - Assuming monitors are
operated for eight hours per day, cost savings
would be 3.8 million per day or 1.4 trillion
per year. Percentage of Power Consumed by CR
Ts - Based on Charles' assumptions, CRTs consume
12.6 of the power produced in California.
-- Analysis from Charles Annis, Photon Dynamics
5
Sandia National Labs Study
A recent study by Fred Cohen at the Sandia
National Laboratories was conducted to solve a
practical problem of determining how to get 250
computers operational in a very small area and
with a limited total power capability. The
office situation meant that not all of the
computers could be on at the same time, meaning
that different projects had to be scheduled for
different times. Moreover, since system turn-on
transients use more energy than when the devices
operate at a steady state, meaning that a
schedule had to be created to turn on/off
computers appropriately. The team at Sandia
solved the problems by creating a database of the
power consumption and turn on transient power
consumption for every device in the laboratory.
The database was then used to determine how many
of what kinds of computers could most efficiently
go on each circuit and to schedule power up
sequences associated with the different devices.
Interestingly, the creation and implementation o
f the Sandia database identified some fascinating
global consequences related to energy
consumption. First of all, the team discovered
that salvaging and upgrading older computers in
order to reduce computer expense budgets did not
always actually save money. According to Dr.
Cohen, We would take an 8 year old display and
attach a 10 connector to get a working unit for
next to nothing, but the power consumption was
higher than a more recent display, so we were
ending up paying more for electricity than we
other wise would have had to.
But it gets worse. The more energy required for
a computer system, the more heat that is
generated, which increases air conditioning
loads. An additional side effect of higher
temperatures is a more rapid degradation of
computing devices resulting in shorter lifetimes
and more failures. As reported by Dr. Cohen,
Every watt of power you save in computer energy,
you save again several times over in air
conditioning costSince almost all of the energy
used by computers goes to heat, we have to
pay for the power we use in computers twice
once for their use and once for the removal
of their resultant heat. Although Fred Cohe
ns study evaluated all computer equipment,
the most telling results related to their
calculations comparing CRT monitors and LCD
monitors. The study indicated that the
power consumption for a flat panel monitor
is about 1/5 the power consumption of a
typical CRT monitor.
6
Electronics Industry of Japan Study
The higher energy costs have been used by
Japanese LCD monitor brands as a means to promote
LCD monitors since the infancy of the LCD monitor
market due to much higher energy costs in Japan.
In a study by the Electronics Industry
Association of Japan in early 1999, it was shown
that the average cost of operation of a 15" LCD
monitor over a 5-year period was lower than an
average 17" CRT monitor due to 80 lower
electricity costs, 75 lower cooling equipment
costs and 58 lower space costs. The biggest
savings in their study were from the space costs
with energy costs accounting for just 8 of the
total operating cost of a 17" CRT. Nonetheless,
the EIAJ study showed that if 50 of Japan's CRT
monitors were converted to LCDs, four power
plants and 181,000 tons of CO 2 emissions could
be eliminated.
7
Comparison of IBM Monitors
A quick comparison of IBMs various monitor
products easily shows the substantially lower
power consumption associated with TFT LCDs. Even
at 200 pixel/inch, the industrys highest
performance TFT LCD monitor, the T221 consumes
the same amount of energy as a high-end Trinitron
CRT Monitor. This is significant since the T221
offers a 12 increase in diagonal size, and 480
more information content. In other words, the
viewable information on the T221 would require
more than 5 of the Trinitron monitors.

• Trinitron models
• From IBMs website, October 28, 2001
• IBM was chosen as an example due to their
  websites
  
• simple power consumption reporting viewable
  across
  
• both TFT LCD and CRT Monitors.

8
Energy Factors, LCD vs. CRT

• Higher electricity costs of CRTs
• Apples-to-apples comparisons are difficult,
  since TFT LCD monitors and CRT monitors have
  many different performance parameters, both
  between the two technologies and within the same
  technology. And many cost factors are
  independent from the display technology,
  (styling, speakers, analog/digital, interface,
  etc). In general, CRT monitors consume about
  2.2 times more energy than an equivalent TFT
  LCD monitor.
• Higher cooling costs to maintain the desired
  room temperature of operating CRTs
  
• The extra energy required to power a CRT
  monitor must go somewhere and its generally
  dissipated as heat into the surrounding room
  environment. This typically translates to a
  need for additional air conditioning. Even in a
  home environment, the extra heat must be cooled
  and will require some additional air
  conditioning. In office environments, the added
  heat can be considerable.
• Lower heating costs to maintain the desired
  room temperature of operating CRTs
  
• Conversely, in cold climates, excess heat
  generated by CRTs may help to reduce heating
  bills. But following this logic would lead
  people to leave their CRTs on even overnight
  clearly an expensive method of heating. And
  since most utility companies reduce winter-time
  rates, the cost of ownership factors still favor
  LCDs throughout the year.

9
Energy Factors, LCD vs. CRT

• Higher power equipment source and installation
  costs of operating CRTs
  
• In some high display-count environments where
  many devices crowd a small area, (financial
  trading centers, control rooms, densely populated
  offices, etc), the heat dissipation from CRT
  monitors cannot be handled by simply running
  existing air conditioning systems more or turning
  down the thermostat, but require entirely new or
  additional air conditioning systems.
  Particularly in high-rise office buildings,
  installation of such new systems can be
  exorbitantly expensive.
• Higher cost of energy in the LCD production
  process
  
• Energy costs associated with TFT LCD fabs are
  higher (when translated to a unit basis), than
  those for a CRT production facility, by
  approximately 3X. This fact leads some observers
  to suggest that savings associated with switching
  from LCD to CRT are much less significant and
  that TFT LCD energy costs simply come earlier in
  the product lifetime. Two problems with this
  suggestion. First the energy costs attributed to
  each LCD is only a few dollars much less than
  the ongoing costs of operating one. Second, this
  analysis forgets the huge energy costs associated
  with the production of glass much higher costs
  for CRT glass tubes than for TFT LCD substrates.
  According to officials from Sharp Corporation,
  the energy costs associated with the production
  of LCDs and CRTs favor CRTs only when considering
  equal sizes, and then only slightly. Since CRTs
  tend to be much bigger than TFT LCDs, on average,
  the per unit energy costs to make CRTs are
  actually much higher. And these costs really are
  due to differential energy rates in
  Japan/Korea/Taiwan (where TFT LCD are
  manufactured) and China, (where CRT tubes are
  primarily manufactured).

10
Energy Factors, LCD vs. CRT

• Increased desktop real estate costs of CRTs
• The thin form-factor of an TFT LCD monitor
  reduces the necessary desk space needed for
  workers. Roughly, a CRT monitor requires 2.4X
  larger footprint. This space can be removed
  from the office layout, thereby saving rental
  (and energy) costs. Considering wall- mount
  versions, TFT LCD monitors can even save more
  space by creating a workable surface under the
  display.
• Shorter useful life of CRTs
• Due to half-life issues associated with the
  CRTs phosphors, TFT LCDs are expected to have
  longer life-spans. Typical estimates are that a
  CRT has a useful lifespan of 4-5 years, while a
  TFT LCD monitor will have a lifespan of 6-7
  years.
• Additionally, due to their higher up-front
  cost, buyers are more likely to employ surge
  protection for their TFT LCD monitors, helping
  to avoid replacement/repair incidents.
• Higher costs of transportation of CRTs
• Due to their larger size and weight, CRTs cost
  more to transport, (which in part is an energy
  related factor). Most buyers do not factor in
  freight to the overall acquisition cost
  particularly important for the direct sales
  channel.
• Higher costs of CRT disposal
• CRT monitors are bulkier and more difficult to
  dispose of, which has an additional
  environmental and economic impact. Its
  uncertain how to calculate any related costs.

11
Energy Factors, LCD vs. CRT

• Comparative readability and other human factors
• Considerable research has consistently
  demonstrated various human factors favoring the
  usage of LCDs vs CRTs, particularly in terms of
  worker productivity. Measuring the economic
  value of such factors, however, is very
  difficult. Advantages include
• Faster word recognition
• Faster word comprehension
• Fewer head turns
• Reduced scrolling
• Reduced eyestrain
• Ease of shifting to portrait mode
• These advantages will improve worker
  productivity translating to additional economic
  advantages, and perhaps to further energy
  savings. If workers can work faster and
  accomplish the same amount of work in a shorter
  period of time, it will reduce such things as
  overtime pay, after-hours energy-related
  expenses, and even legal expenses related to
  claims for eyestrain, etc.
• There is also a strong argument that enhanced
  readability on-screen, as provided by TFT LCD
  monitors will reduce printing expenses and
  associated energy costs.
• Some of these advantages are reviewed in the
  following pages.

12
Search Time By Display Technology
Source Dr. Martina Ziefle, Technical University
of Aachen, Germany, DisplaySearch High Resolution
Symposium 2001.
13
LCD vs. CRT ? Higher Productivity
Better Word Comprehension
18 Viewing Distance
Word Recognition
Wright, S.L., et. al. (1999) SID99 Digest,
346-349.
14
A 15 eye movement is generally accompanied by a
head turn. Using this rule you can estimate the
number of head turns required to scan a screen
width from an eye point 18 inches away.
LCD vs. CRT ? Higher Productivity
Reduced Head Turns
8.5 x 11.0 paper requires no head turns.
Paperback books are sized to minimize head turns

• 21 UXGA CRT 4 head turns
• 15 UXGA TFT 3 head turns
• 15.0 TFT vs. 21.0 CRT offers
• Same information content
• Better visual clarity
• Smaller footprint
• Higher Worker Productivity

Higher dot pitches mean smaller display
diagonals. This means fewer head motions and
stiff necks.
Based on research from NASA Ames Research Center
15
LCD vs. CRT ? Higher Productivity
Reduced Scrolling

• -- High resolution reduces scrolling
  substantially.
  
• -- Reduced scrolling results in
• Reduced Printing Expenses
• Reduced On-line Wait Times (and related
  expenses)
  
• Better On-line hit Utilization
• (If the user needs to scroll extensively through
  an on-line store in order to find items
  especially the buy button -- the buying
  experience is diminished and sales are
  potentially lost).
• Higher resolution graphics will result in more
  realistic viewing on web-sites.
  
• (The buyer will be able to better see whats
  offered).
  
• -- Needed 3rd Party Study related to the
  negative impact of scrolling.

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Reduced Scrolling
LCD Pixel Density Advantage
1024x768

• Note 800x600 requires five down-scrolls to get
  to equivalent 1600x1200 content.
  
• High-Res reduces Printing
• High-Res reduces On-line Waits

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Adding it Up
Input Fields for Energy Cost Calculator
-- Based on inputs from Dell Computer
18
Energy Cost Calculator Outputs
Note Other Calculators on the Web
NEC/Mitsubishi www.necmitsubishi.com/mark
ets-solutions/index.cfm IBM www.pc.ibm.
com/us/accessories/access_promo/flatpanel/tour/sav
ings.html
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Energy Cost Calculator Outputs
20
Energy Savings Calculator -- Notes

• Improved Productivity associated with TFT LCDs
  can be accounted for by reducing the amount of
  time the TFT LCD will be on during each day.
  
• Differences in climate/seasons can be accounted
  for by altering the number of hours per day
  and/or the number of weeks per year that the air
  conditioning is active.
• The cost of energy differs by season, by
  region. The 0.1100 cost indicated here is
  rather low on a worldwide basis.
  
• The cost of office space varies widely from
  city to city, from country to country.
  20.00/sq ft is very low, especially for cities
  like New York or Tokyo, but at the same time,
  the benefits of shifting to smaller footprint TFT
  LCD monitors will take time to actually impact
  office layouts.

21
Conclusions

• There is definitely a substantial energy
  savings favoring LCDs over CRTs.
  
• Over the life of the products, the Total Cost
  of Ownership favors LCDs over CRTs.
  
• There is a marketable advantage for companies
  to favor sales of LCDs over CRTs, both due to
  simple economic and to environmental factors.
  
• Posting a Dell-specific Energy savings
  Cost-of-Ownership calculator that is highly
  prominent on Dells websites and promotional
  literature should help buyers make decisions to
  buy TFT LCD Monitors rather than CRT Monitors.