The File - Feb 1 , 2009 - (Page 1)

India’s fortnightly focus on electronics design February 1-15, 2009 Solar powers green future By Ramprasad Ananthaswamy Director Power Management Products Texas Instruments India cent, hydropower at 6.3 per cent, nuclear power at 6.0 per cent, and others at 0.9 per cent. Power plants using fossil fuels like petroleum, natural gas and coal result in 2,771.5 “Carbon footprint” is an oftenused term these days. It is used to popularise the practice of minimum consumption of energy in day-to-day living without sacrificing the quality of life. There are two sides to this statement. One is the consumption of less energy through better efficiency, thereby reducing energy production levels. Second, the production takes place in an environment-friendly manner. Both these aspects put together will guarantee a smaller carbon footprint. The worldwide energy demand is currently supported by petroleum at 36.8 per cent, coal at 26.6 per cent, natural gas at 22.9 per Ananthaswamy: The world is now looking at non-polluting technologies and alternative energy sources. For a tropical country like India, solar energy is a good choice. crore (27,715 million) tons of carbon emissions, which is set to increase to 3,712.4 crore (37,124 million) by 2025. These numbers equate to 1.6 crore (16 million) tons of carbon dioxide being emitted into the atmosphere every 24 hours by human consumption of this energy. We are depleting fossil fuels 100,000 times faster than they are formed. The world is now looking at non-polluting technologies (e.g. fuel cells), clean technologies (e.g. wind, solar, etc.) and alternative energy sources. Biomass, geothermal, hydro, wind and solar are some of the prime examples of alternative energy sources. For a tropical country like India, solar energy is a good choice. Solar panels Advances in solar photovoltaic (PV) panels are happening at a fast and furious rate. The latest panels are expected to have an even longer life expectancy than the older models. Recent significant advances in solar panel technology have been in power density—the latest panels are the same size as older models but are equipped with more power per square foot. Types of solar panels are: Crystalline silicon—Crystalline solar cells have been available for a long time. Each cell starts out with a silicon “wafer” that is processed into a solar cell. A typical solar cell is just a little thinner than a credit card. Although it is fragile on its own, it is very robust inside a solar module. Crystalline solar cells can be “hand-soldered” together to form a circuit. These solid-state devices can last for a hundred continued on page Powering portables with supercapacitors By Keith Curtis Technical Staff Engineer Microchip Technology, Inc. Inside Trends 2 DSCs improve power efficiency Designers of portable electronics typically have a love-hate relationship with their batteries. They love the portability and energy density of batteries, but hate the complexities of charging and the limited lifetime of chemicalbased storage. As a result, there has been a concerted effort to develop alternative methods for storing electrical power. One such method uses supercapacitors. Supercapacitors have both advantages and disadvantages, when compared to traditional battery-based systems. On the plus side, they have a virtually unlimited lifetime (10,000,000 charge/discharge cycles), they can charge and discharge at phenomenal currents (upwards of 1,000A), and they are largely immune to temperature variations. However, they do sig- nificantly lag behind batteries in energy density (typically 3-5 per cent of Li-Ion batteries) and cost (typically 10X to 15X). However, supercapacitors are finding applications in designs where their benefits outweigh their limitations. Examples include applications that have significant maintenance costs with regard to battery replacement, such as remote emergency equipment. An additional example includes equipment that must perform in environments with significant temperature differentials, such as desert or arctic monitoring stacontinued on page Community 8 VLSI 2009: Pushing India’s design potential Events 8 ISA Vision Summit 2009, COMPONEX NEPCON 2009, ISEABB ‘09, Geomatrix ‘09, Convergence India 2009 Sponsors 3 National Semiconductor www.eetindia.com http://www.eetindia.co.in/SEARCH/SUMMARY/industry-news/%22crystalline%20silicon%22.HTM?ClickFromNewsletter_090201 http://www.eetindia.co.in/SEARCH/SUMMARY/industry-news/solar.HTM?ClickFromNewsletter_090201 http://www.powerdesignindia.co.in/SEARCH/SUMMARY/technical-articles/battery.HTM?ClickFromNewsletter_090201 http://www.powerdesignindia.co.in/SEARCH/SUMMARY/technical-articles/supercapacitors.HTM?ClickFromNewsletter_090201 http://www.eetindia.com/STATIC/REDIRECT/Newsletter_090201_GS01.htm http://www.eetindia.com/STATIC/REDIRECT/Newsletter_090201_EETI02.htm

Table of Contents for the Digital Edition of The File - Feb 1 , 2009

The File - Feb 1 , 2009