All these computers need electricity though some more than others. Desktopsneed more power than laptops and desktops with cathode ray tube (CRT)displays use the most energy of any type of PC. Liquid Crystal Displays(LCDs) require less power than CRTs. Liquid Crystals were first describedin 1888 this was 13 years after Hook invented the first CRT. It is quiteamazing that the physics behind these displays were first discovered overone hundred twenty years ago.
A new model desktop with a CRT requires about 200 watts of power. The samedesktop with a LCD monitor uses 150 watts of power or some 50 watts less.If one uses the computer 4 hours per day or some 1,500 hours per year simplybuying a LCD monitor saves some 75 kilowatt hours each year. This amount ofelectricity can power an average Tiburon home for 3 days. During the other7,200 hours of the year when the computer is in the idle mode the LCDmonitor will save about 3 watts of power compared with the CRT. This isanother 21 kilowatt hours of annual savings or about another day's worth ofpower usage in the average home. Buying a laptop instead of a desktop andLCD monitor saves 100 watts of power and would save about 150 kilowatt hoursof electricity per year or about 6.5 days worth of the average homes total electricity usage.
In 1997 there were only 100 thousand LCD monitors sold, this year 180,million or 90% of the all the monitors that will be sold in the world arebased on LCD technology. Amazingly 80% of these LCD monitors are now madeon the island of Taiwan and 0% in the USA. This year we will cross thepoint where half of the PCs sold will be laptops. We are indeed fortunatethat more efficient technologies for monitors and computers have beendeveloped. If we assume that half of the next billion PC that will be soldover the next 7 years are laptops, these 500 million computers each saving100 watts of power implies that the peak demand for electricity will be50,000 megawatts less. This means 50 large 1,000 megawatt power plants willnot need to be constructed. The reduced carbon dioxide emissions by nothaving 50 coal fueled power plants operating 1,500 hours per year is aboutequal to twice the carbon content of the entire sugar crop of Brazil of 35million tons of sugar. Conversely the extra 1 billion computers will requirethe construction of 150 large 1,000 megawatt power plants to meet this peakpower demand. The carbon emissions from 150 additional power generationstations, approximately equals the carbon content of the world's entiresugar crop of 150 million tons. This is not so sweet news.
All these added sales of computers will make Bill Gates a very happy man andthat is why he is the G word of the day.