Do you wish to run the Servers etc from a 12v supply or a 240/110v AC supply?
We would want the servers to run off AC power, since that's what the chargers run on as well, so presumably our entire system would run on AC.
Are you looking to charge the laptops or just run them directly during daylight hours?
The best solution we know of is to have chargers located at school. The children spend the day using their laptops and letting them charge while at school, then they go home and use the laptop until the battery runs out, then they return the next day and charge it up again.
How many hours will they be used for a day?
This depends on the curriculum at the school and to what extent the laptops are integrated into the teaching. It could be as much as all day at school and as long as the battery permits at night. Or it could be only 1-2 hours at school. We're going to assume/hope that the children use the laptop when they go home, since they will be taking it with them (unless there is legitimate concern that the laptops might be stolen, which we are not aware of). Not quite sure what you mean by this question. I would assume that the child comes to school each day with a dead battery, so we need to plan on fully charging the laptops once or twice a day (once in the morning, and the laptops might remain plugged in rest of the day or be in use and then charged again before leaving) but again, this would all depend on the school.
Do you require additional power for lighting within the school?
I would assume that if we're needing to provide our own electricity, that they've been working so far without lighting. My understanding is that these schools would be very poor and not very big (so one or two rooms). We could look into budgeting in lighting, but I don't think it's really essential, since they attend school during the day when it's sunny out.
Operational times of the building?
Depends on the school, but I would say between 8-10 hours a day. With children in school 6-8 hours a day, or at least as long as it is light out.
Suggested budget for 500w/hour system?
What do you mean exactly? For installation or maintenance? Maintenance should be zero cost. and the system needs to be tested and shown to be reliable and rugged and not prone to breaking. Budget for the installation is not yet determined. We'd appreciate some feedback/rough suggestions, but we'd like to do it as inexpensively as possible while still making a rugged system. We will most likely be applying for additional funding (additional to the $10,000 provided by OLPC).
Operational hours of the laptop once charged?
If the battery is operating at full capacity (full screen brightness, full cpu, and full wireless) then the battery lasts for about 3 hours (so that's operating at about 5 watts). If you dim the screen, you get
an additional 2 hours, if you use the cpu less, another 2, and no wifi you get another 2 or 3. All said, you can stretch the batter to 10-11 hours if all you're doing is reading text on a black and white screen.
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