Chapter 5 Green Computing IT Professionalism http://library.vtc.edu.hk/english/eres/evideo.php?cid=tvb&pid=4&eYear=2002&eid=1272&submit=Go

Introduction Green computing, sometimes called green I.T., is the study and practice of using computing resources in an efficient way so as to achieve the goals of, among others: Reducing the use of hazardous(有危險的) materials; Maximizing energy efficiency during a product’s lifetime, and Promoting recyclability and biodegradability of defunct products and factory waste.

Introduction Green computing advocates the triple bottom line (TBL): Ecological(生態) performance Social performance Financial performance A company’s responsibility is not only maximizing profit for its shareholders(股東), but also has a responsibility toward its stakeholders.

Green Computing People It is the company’s human capital, and the company must treat its stakeholders such as suppliers and labor fairly. People It is the company’s natural capital. It refers sustainable environmental practices by reducing its ecological footprint(足跡) (e.g. careful consumption of energy, reducing manufacturing waste, disposing toxic waste in a safe and legal manner etc.) Planet The profit of a triple bottom line company is the economic benefit not only limited to its shareholders, but also to its host society with lasting economic impact on its economic environment. Profit

Why green computing? Global warming: Over the past 100 years global temperature has increased by an average of 0.6 C. The main causes of global warning are: Coal burning power plants; Exhaust gases from petroleum-based automobiles; Factories and waste vents(排污管道) of other human activities. The carbon dioxide (CO2) in the atmosphere has increased by 31% since 1750 of the pre-industrial level, being caused by the burning of fossil fuel (75%) and deforestation (25%).

Carbon Footprint A carbon footprint is “the total set of GHG (greenhouse gas) emissions caused directly and indirectly by an individual, organization, event or product” (UK Carbon Trust 2008). It has units of tons (or kg) of CO2 equivalent Carbon offsets refer to the reduction of carbon emissions through the development of alternative projects such as solar or wind energy or reforestation.

Carbon Footprint A carbon footprint is made up of the sum of two parts: The primary footprint refers to the measure of direct emissions of CO2 from the burning of fossil fuels including domestic energy consumption and transportation (e.g. cars and planes). The secondary footprint refers to the measure of indirect CO2 emissions from the whole lifecycle of products, from manufacture to eventual breakdown, e.g. CO2 emissions during extraction of coals or fossil fuel.

Typical carbon footprint of appliances Usage Per Use Cost/year Kg CO2/year Microwave Oven 96 times / year 0.945 kWh per use £9.07 39 Washing Machine 187 washes / year EU energy label A-rated gives an average consumption at 40°C £11.78 51 Electric Tumble Dryer 148 uses / year 2.50 kWh per cycle £37.00 159 Kettle 1542 uses / year 0.11 kWh per use based on heating 1 Liter of water £16.90 73

Typical carbon footprint of appliances Usage Per Use Cost/year Kg CO2/year Gas Oven 135.1 uses / year 1.52 kWh per use £7.60 38 Electric Oven 1.56 kWh per use £21.08 91 Standard Light Bulb 4 hours / day 100 W per second £14.60 63 Low Energy Light Bulb 18 W per second £2.63 11

Typical carbon footprint of TVs Appliance Usage Per Use Cost/year Kg CO2/year TV – CRT (Cathode Ray Tube) 34-37 inch On Power 6.5 hours / day 263.9 Watt £62.61 269 TV – CRT (Cathode Ray Tube) Standby 17.5 hours / day 4.2 Watt £2.68 12 TV – LCD 34-37 inch 198.5 Watt £47.09 203 TV – LCD 1.8 Watt £1.15 5 TV – Plasma 34-37 inch 211.1 Watt £50.08 215 TV – Plasma 3.6 Watt £2.30 10

Typical carbon footprint of desktop computers Appliance Usage Per Use Cost/year Kg CO2/year Desktop (with LCD) On Power 17.5 hours a day 150 Watt £35.58 153 On Power 24 hours a day 205 Watt £48.8 210 Notebook (build-in LCD) With power management switch on as default 50 Watt £16.2 70

Carbon Footprint Although it is the smartest device in the house, it is quite often not very smart in consuming energy. Most people have more computer power than they need A modern desktop (together with its LCD) consumes 150-watt, but many are not powered off when not in use A few PC with LCD automatically power them down. A notebook computer with power management switch on consumes about 50-Watts

Carbon Footprint How to reduce energy consumption? Enable power management that power off sub-system not in use Turn off computers when they're not in use

The 3R’s: Reduce, Resuse and Recycle Use less hazardous materials and less waste of energy Reuse To maximize a product’s lifetime Recycle Recycle the material used in IT products and promote their biodegradability

Common Approaches to Green Computing They are simply ways to use less resources and in a smarter fashion. Algorithm efficiency Virtualization Terminal servers Power management Power supply units Storage Video card and display Material recycling Telecommuting

Common Approaches to Green Computing – Algorithm efficiency Better algorithm, more energy efficient: Use less energy Use less hardware Examples of algorithm efficiency are: More efficient way of coding a program. More efficient use of computer memory, which may, but does not necessarily always, come into conflict with more efficient programming. More efficient transmission of data (e.g. balancing the resources (time) needed to compress and decompress data vs. the resources (time and expensive bandwidth) it takes for transmitting the data.)

Common Approaches to Green Computing – Virtualization Virtualization refers to the abstraction of computer resources. For example: Run several logical computer systems on one set of physical hardware. It saves the resources (material, labor and energy) used in making the hardware It also saves the ongoing resources needed (e.g. power used in running and cooling the systems) to use the hardware. For examples, Intel and AMD build proprietary virtualization enhancements to the x86 instruction sets into each of their CPU product lines to facilitate virtualized computing.

Common Approaches to Green Computing – Terminal Server Terminal servers are also called thin client (or slim or lean client). A terminal server is a client computer or client software in client-server architecture networks which depends primarily on the central server for processing activities. It mainly focuses on transferring input and output between the user and the remote server.

Common Approaches to Green Computing – Terminal Server A thin client is a PC with only user interface, certain frequently used applications, and a networked operating system. It can be a very small, low-powered device giving lower costs to purchase and to operate per seat. The server, or a cluster of servers, has the full weight of all the applications, services, and data. It is easier to do system management, at lower costs, but with the advantages of networked computing such as central storage/backup and easier security. Not only the initial equipment cost is lower, the energy cost, technician cost and the rising cost to IT waste disposal, thin client is certainly an attractive option.

Common Approaches to Green Computing – Storage Hard disks are the major devices to store data. Smaller form factor (e.g. 2.5 inch) hard disk drives often consume less power per gigabyte than physically larger drives. Hard disks are used more and more as storage farms because of the following reasons: As hardware prices fall, there is a tendency to use more hard disks for storage, backups and archives because it can be done much easier and faster. Previously the data is put on offline devices such as tape storage.

Common Approaches to Green Computing – Storage Also, as on-line data requirement is increased, data are put on hard disks more and more for easy and instant access. As more hard disks are used, more power is required to run them and cool them. Solid-state drives store data in flash memory or DRAM (Dynamic Random Access Memory). Since there are no moving parts, power consumption may be reduced somewhat for low capacity flash based devices.

Common Approaches to Green Computing – Video Card and Display A fast Graphics Processing Unit (GPU) may be the largest power consumer inside a computer. They are used when high quality displays are needed for 2D and 3D graphics processing. It generates so much heat that usually it has its own dedicated cooling fan and heat sink. Use GPU only when necessary and select one based on average wattage or performance per watt. If possible, use video display output from the motherboard, or a shared terminal, thin client or desktop sharing software.

Common Approaches to Green Computing – Video Card and Display Video Display Cathode Ray Tube (CRT) uses more energy and generates more heat. However, they are getting less and less popular because of their bulkiness and consume more energy than LCD monitors which use less energy and which are cooler.

Common Approaches to Green Computing – Material Recycling Reuse: The lifecycle of computer systems can be extended by redeploy(重新配置) for other uses, even when it has become obsolete(廢棄的) for what it is originally intended. For example, a “high-speed” computer may not be fast anymore because of update in software which requires a newer model. The older model can be redeployed for use in less demanding applications, or donated to charity and non-profit organizations.

Common Approaches to Green Computing – Material Recycling Recycle: This includes salvaging(挽救) parts from outdated system and recycling them through retail outlets and recycling centers. While this can extend the use of these still usable parts, it also avoids the toxic material in them, such as lead and mercury out of landfills. Other computer accessories and supplies, such as printer cartridges, paper and batteries may be recycled as well.

Common Approaches to Green Computing – Material Recycling In reality, however, material recycling has its down side. Refitted computers are usually less energy efficient because of its older parts such as an old model CPU, CRT and large foot print hard disk drive. Quite often, obsolete(淘汰的) computers are shipped from North America and Europe to less developed countries that have less stringent(嚴厲的) environmental standards. It is estimated that 80% of the post-consumer e-waste collected for recycling is shipped to countries such as China, India and Pakistan.