Talk:Deployment Guide/Power Infrastructure

Alternative Power Sources

We should consider at least the following possibilities in terms of practicality and environmental impact.

• Solar is well covered on this page.
• Wind.
• Water. The beaver is the MIT mascot. Can we put a beaver-cam on a beaver dam with a microhydro unit and show how many XOs it can power?
• Ethanol, in Brazil, at least
• Biodiesel, using palm oil, for example, in areas of recent glut, such as Nigeria. Soap is a valuable byproduct.
• Biomass (methane).
• Animal power. Cow power is under development. I (--Mokurai 14:51, 22 March 2008 (EDT)) would like to invite MIT engineers to create a hamster-powered system with a hamster-cam. Then we can ask how many hamsters it takes to power an XO. ^_^
• Child power is where we started. How viable is it? I hear that children can generate power faster than the battery can absorb it. Perhaps children can take turns on a gang charger.

Watt-hours

I think I fixed the watt-hour terminology. Although I don't think watt should usually be capitalized. I also did the math in the example. I don't think that the example is a good one though. Although the server and the modem may be active for the full day or more, the laptops may not be in use every minute they are at school. Also it is probably more cost-effective to run a smaller generator for a longer period of time and not rely on running on led-acid batteries most of the time.

Another thing to think about is what happens when come to school on a Monday morning with their laptop batteries discharged. If all 500 plug in at once, you will probably be drawing on the order of 500 laptops * 20 watts/laptop = 10,000 watts or 10KW. You will probably limit the number of users that can charge their laptops at once.

It would be good to get some feedback from the pilot schools to see how many hours a day students use their laptops, both in school and at home.