25-03-2011, 11:30 AM
Green-Computing.ppt (Size: 835 KB / Downloads: 288)
Green Computing
• Why
– computer energy is often wasteful
• leaving the computer on when not in use (CPU and fan consume power, screen savers consume power)
– printing is often wasteful
• how many of you print out your emails or meeting agendas
• printing out partial drafts
• for a “paperless” society, we tend to use more paper today than before computer-prevalence
– pollution
• manufacturing techniques
• packaging
• disposal of computers and components
– toxicity
• as we will see, there are toxic chemicals used in the manufacturing of computers and components which can enter the food chain and water!
Energy Use of PCs
• CPU uses 120 Watts
• CRT uses 150 Watts
– 8 hours of usage, 5 days a week = 562 KWatts
• if the computer is left on all the time without proper power saver modes, this can lead to 1,600 KWatts
– for a large institution, say a university of 40,000 students and faculty, the power bill for just computers can come to $2 million / year
Energy use comes from
– electrical current to run the CPU, motherboard, memory
– running the fan and spinning the disk(s)
– monitor (CRTs consume more power than any other computer component)
– printers
Reducing Energy Consumption
• Turn off the computer when not in use, even if just for an hour
• Turn off the monitor when not in use (as opposed to running a screen saver)
• Use power saver mode
– in power saver mode, the top item is not necessary, but screen savers use as much electricity as any normal processing, and the screen saver is not necessary on a flat panel display
• Use hardware/software with the Energy Star label
– Energy Star is a “seal of approval” by the Energy Star organization of the government (the EPA)
• Don’t print unless necessary and you are ready
• Use LCDs instead of CRTs as they are more power efficient
Manufacturing
• Microchip fabrication has over 400 distinct steps which involve 4 general phases
• Throughout, the process requires a great deal of ultra-pure water and the chips are bathed in chemical solvents
– the resources used are shown below
Chemical Elements Used: Lead
• used in soldering of printed circuit boards and other components
– also used in glass for CRTs
• It is estimated that between 1997 and 2004, 1.2 billion tons of lead was used in computer components
• The problem:
– lead can cause damage to the central and peripheral nervous systems, blood system, kidneys, endocrine system and cause negative effects on child brain development
– lead accumulates in the environment and has toxic effects on plants, animals and microorganisms
– electronics contribute 40% of the total amount of lead found in landfills and can make its way from landfills into the water supplies
Chemical Elements Used: Mercury
• Mercury is used in
– batteries, switches, housing, printed circuit boards
– mercury is found in medical equipment, data transmission equipment, telecommunications equipment and cell phones as well
– if is estimated that 22% of the yearly use of mercury is in electrical and electronic equipment
• although a small amount of mercury is used, it is used in nearly all computer construction amounting to 400,000 pounds of mercury used between 1997 and 2004
• The problem
– mercury spreads out in water transforming into methylated mercury which easily accumulates in living organisms
– it enters the food chain through fish that swim in polluted waters
– methylated mercury can cause chronic brain damage
Other Chemical Elements
• Cadmium is used in resistors for chips, infrared detectors and in semiconductors (plus older CRTs)
– estimated that between 1997 and 2004, 2 million pounds of cadmium was used in computer components
• The problem:
– cadmium is classified as toxic, these compounds accumulate in the human body, particularly the kidneys
– cadmium is absorbed through respiration and also food intake
– cadmium has a half life of 30 years so that cadmium can poison a human body slowly through the human’s life
• Hexavalent Chromium (Chromium VI) is used to treat steel plates (an anti-corrosive) and it is estimated that between 1997 and 2004, 1.2 million pounds were used in computer components
– if you’ve seen Erin Brokovich, you know that this can lead to cancer and a number of other medical problems
Plastics
• Plastics are found throughout the computer, largely from casings but also internally to hold components together
– 4 billion pounds of plastic were used to build computers and components between 1997 and 2004
• One specific form of plastics used is polyvinyl chloride (PVC) which is used in cabling and housings
– PVC is difficult to recycle and the production and burning of PVC generates dioxins and furans
• The plastics in computers are often treated with flame retardant chemicals, particularly brominated flame retardant
– these chemicals can act as endocrine disrupters and increase risk of several forms of cancer
– they have been found entering the food chain
• Chemical Elements Found in Computers and Components
• Elements in bulk: lead, tin, copper, silicon, carbon, iron and aluminum
• Elements in small amounts: cadmium and mercury
• Elements in trace amounts:
– germanium, gallium, barium, nickel, tantalum, indium, vanadium, terbium, beryllium, gold, europium, titanium, ruthenium, cobalt, palladium, manganese, silver, antimony, bismuth, selenium, niobium, yttrium, rhodium, platinum, arsenic, lithium, boron, americium
• List of examples of devices containing these elements
– almost all electronics contain lead & tin (as solder) and copper (as wire & PCB tracks), though the use of lead-free solder is now spreading rapidly
– lead: solder, CRT monitors (Lead in glass), Lead-acid battery
List Continued
• List of examples of devices containing these elements
– tin: solder
– copper: copper wire, printed circuit board tracks
– aluminum: nearly all electronic goods using more than a few watts of power
– iron: steel chassis, cases & fixings
– silicon: glass, transistors, ICs, Printed circuit boards.
– nickel & cadmium: nickel-cadmium rechargeable batteries
– lithium: lithium-ion battery
– zinc: plating for steel parts
– gold: connector plating, primarily in computer equipment
– mercury: fluorescent tubes (numerous applications), tilt switches (pinball games, mechanical doorbells)
– sulphur: lead-acid battery
– carbon: steel, plastics, resistors
Disposal
• Consider that the average computer lifespan is about 2 years (cell phones < 2 years)
– 10 years ago, the lifespan of a computer was 5 years
– between 1997 and 2004, it is estimated that 315 million computers became obsolete (and were discarded, donated, or recycled)
• 183 million computers were sold in 2004 (674 million cell phones!)
• New users in China (178 million by 2010) and India (80 million by 2010) will require the creation of new computers
• Disposal of these devices constituted 20-50 million tons per year (about 5% of the total waste of the planet)
– this waste is called e-waste
– where are we going to put all of it?
Land Fills
• Europe has outlawed using landfills for computer components
– the US and Europe export a lot of e-waste to Asian landfills (especially China even though China has outlawed the importing of e-waste)
– in addition, incineration of computer components leads to air pollution and airborne toxins
Other Solutions
• Reuse: donate your computer components to people who may not have or have lesser quality computers
– inner city schools, churches, libraries, third world countries
• this however leads to the older computers being dumped but there is probably no way around this as eventually the older computers would be discarded anyway
• Refurbish: rather than discarding your computer when the next generation is released, just get a new CPU and memory chips – upgrade rather than replace
– while you will still be discarded some components, you will retain most of the computer system (e.g., monitor, the system unit housing, cables)
• Are there adequate incentives to do either of the above? Do computer companies encourage refurbishing/upgrading?
One More Solution: Recycling
• If companies can recycle the plastics and other components, this can greatly reduce waste and toxins
– however, the hazardous materials in e-waste can harm the recycle workers if they are not properly protected
• in undeveloped countries, a lot of the recycling chores are left up to unprotected children!
• Developed countries now have facilities for recycling e-waste
– however, in Europe, the plastics are discarded instead of recycled because the flame retardant chemicals are too toxic to work with
• To resolve these problems, the computer manufacturers must start using recyclable chemicals
How Do the Companies Rate?
• 8: Nokia - regained its top position for eliminating the worst chemicals from many products
– still needs to report on its recycling rate percentage
• 7.3: Dell - still among the top but loses points for not having models free of the worst chemicals
– strong support for global take back
• 7.3: Lenovo - dropping down the rank for not having a clear global take back program
– still missing out on products free of the worst chemicals on the market
• 7: Sony Ericsson - among the top with clear timeline to have products free of the worst chemicals by 2008
– need better chemicals take back reporting program
• 6.7: Samsung - strong position for having a good chemical policy, but still lack products that are free from the worst chemicals
– its take back system is not yet global and need improvement
• 6.7: Motorola - some products on the market are free from the worst chemicals but loses points for not providing clear timelines for eliminating these chemicals in all products
– score points on reporting the recycling rate
• 6: Toshiba - good improvement particularly on waste and take back criteria
– moved forward for providing some models without the worst chemicals and for timelines for complete phase out
• 6: Fujitsu-Siemens - some models free of worst chemicals, but loses point for a weak take back and recycling program
• 5.7: Acer - standing still with improved chemical policies but no models free of the worst chemicals
– needs to improve on take back program
• 5.3: Apple - top mover with concrete timelines to eliminate the worst chemicals
– loses points for not have a green product on the market and for a weak take back program
• 5.3: HP - a free-faller, dropping down for failing to provide clear timelines for eliminating the worst chemicals
– it looses points for weak definition of take back policies
• 5: Panasonic - moving up for making available products free of the worst chemicals
– loses point for poor take back program
• 4: Sony - at the bottom of the rank for losing penalty point for inconsistent take back policies
– some models without the worst chemicals