On Tuesday 08 March 2005 13:49, pepone pepone wrote: > Are you including the power and materials that are needed to build the > new hardisk I think that if you include this tow factors you dont > contribute to the power conserved because is to much expensive build > the new hardisk in terms of Ecology and power. > > In a extreme case you must include the power used in all derivated > procces to get this new hardisk. Let's assume that it takes x kWh to produce a harddisk. In the case where the computer is turned off every day, we assume that it is on for 9 hours every day. We assume that the power consumption of the computer is 50 W. In the case when the computer is turned off every day we assume that the hard disk will last for 3 years and in the case where it is always on we assume 5 years. Per day the average power consumption including production is 1/(365*3)*x+9 h*50 W for the on/off case. For the alway on case it is 1/(365*5)*x+24 h*50 W. If we require the per day consumption to be equal, we have 2.05 MWh to produce the harddisk. Unfortunately I have not been able to find information about what it requires of energy to produce a harddisk. However according to Volvo you can produce a whole car on that amount of energy, all processes included. http://www.volvocars.com/AboutVolvo/EPI/Europe/epi_production.htm Regards Torben
