Technology for the Future Prediction is very difficult, especially about the future.

Transcription

1 Technology for the Future Prediction is very difficult, especially about the future. CCST Mar, 2012 Niels Bohr Dr. Hayden Kwok-Hay So Department of Electrical and Electronic Engineering Global Warming 2 Compelling Evidence Global sea level rose about 17 centimeters in the last century The Earth has warmed since 1880 with all 10 of the warmest years occurred in past 12 years Oceans have been warmed by F since 1969 Ice sheets have been shrinking Glaciers 5-yr temperature anomalies 1881 to 2009 have been retreating Source: source: NASA 4 E-waste Waste Electrical and Electronic Equipment (WEEE) Broadly speaking: Any discarded electronic devices Computer, monitor, mobile phones, DVD player, refrigerator, etc All of them contain electronic components: e.g. integrated circuits (IC), transformers, capacitor, etc Electronic components connected with printed circuit boards (PCB) PCB is made of many layers of plastics and metal wires 5 6 1

2 WEEE-specific Problems (1) WEEE-related Problems Contain highly harmful substances: Low Lead in CRT monitory Mercury in LCD display Cadmium in PCB and old Ni-Cd batteries Brominated flame retardant (BFR) in PCB, connectors and cables Lack Rapidly increasing computer ~3 years mobile phone ~18 months Rapid increase in electronic market in developing world Largest increase (in terms of % by mass) in municipal waste in many urban cities of facilities Dismantling, recycling and discarding ewaste requires dedicated facilities Requires highly trained worker to classify waste: Short lifespan of electronic devices: awareness Many people do not understand the environmental and health risk of e-waste E.g. Treatment of a CRT monitor is very different from an LCD monitor 7 WEEE directive WEEEman WEEE 3.3 directive by the European Commision 2002/96/ EC Principle: The manufacturer/ importer of EEE has to bear the responsibility of the lifecycle of the equipment Includes manufacturing and disposal Requires producers to bear the responsibility of collecting WEEE tons sculpture made with electronic waste A warning label in a headphone bought in The bar indicates it is a product from after Recycling Products (US) Case Study: Apple Gift Card for recycling old computer Manufacturing products has higher carbon footprint than using them 11 Free recycle with shipping paid Old batteries recycling at Apple stores 2

3 Recycling Products (HK) Not just waste 13 Urban Mining 14 Valuable e-waste E-waste also contains many valuable materials Valuable metal: Gold, silver, aluminum, copper 1 tonne of cell phone è 5g gold (more than 1 tonne of ore) 100kg copper 3kg silver Rare 15 Recyclers in Guiyu earth elements: Indium from LCD Antimony from silicon wafer 16 From TIME Photos A small village near Shantou, China One of the largest electronic recycling center Unfortunately, very poorly managed People have little protection against the harmful materials in the e-waste pile

4 Black market for e-waste Administrivia Case: Homework unusable TV illegally exported to West Africa 2 is out Individual homework Due Apr 10, 2012 Project: Website due on 18/4 3pm (before lecture) Editing will be disabled afterwards Final project report due 27/4 11:59pm Individual report Final presentation order online Peer review assignment online BP Oil Spill Mexico Gulf Renewable/Clean Energy 22 Wind Farm Blowing of turbines drive generators Clean and reliable May generate day & night But Only work in areas with high wind Not reliable Large blades kill/scare away birds Nuclear Bio Fuel Solar Clean Renewable Wind GeoThermal Fossil Land-based Ocean-based

5 Solar Energy Helios n Convert radiation from the Sun into electricity by photovoltaics and other means. n Pros: always available (during day time), renewable, free n Cons: doesn t work at night, cloudy day, large area n Increase in efficiency recent years: 17% in 1980s, around 40% in 2007 Biofuel: Biodiesel and Ethanol n Generate electricity through Biomass Sugar cane, core, animal manure, etc n Make biodiesel/ ethanol to use in car n Pros: Net carbon neutral (hopefully) n Cons: Food for electricity? Pest? Nuclear - Pros n Some experts regard nuclear energy as a clean energy source: It does not generate green house gases (e.g. CO2) during the process n So long as the radioactive by-product is handled properly, the process is safe Nuclear - Cons n The danger associated with nuclear is large especially with regard to the treatment of radioactive waste Natural/man-made disaster n Germany: Nuclear currently supply ~25% of electricity Eliminate nuclear power entirely by 2022 Replaced by renewable energy sources, mostly wind Biodegradable Circuit Boards n All electronics gadgets contain one or more PCBs n PCBs are made of many layers of plastics and thin lines of metals n Contains lots of harmful heavy metal n Biodegradable PCB? Season 2: Gadget 5

6 Biodegradable Transistors n Conventional transistors (all integrated circuits) are built using (tiny) silicon + metal n Biodegradable transistors are made of biodegradable polymers, silk, etc Reduce n Recall the differentiation between want and need n Judge when you really need to get a new phone, TV, etc n Need to drive down production of unused products 32 Summary n We need to find a better way to care for the world n Technology both helps and hurts the world at the same time n More innovations needed n Huge engineering effort Cross disciplinary View of the Earth as seen by the Apollo 17 Reduce Do you part: Take care of Planet Earth. Recycle Reuse 6