[hackerspaces] Raspberry Pi - $25 ARM based PC

[Chris Weiss]

On Thu, May 5, 2011 at 11:10 AM, john arclight <arclight at gmail.com> wrote:
> We've done several solar projects. You need to multiply the wattage of your
> loads by the number of hours each is expected to be on.
>
> For the panels, figure on 2-5 sun hours per day, depending on location and
> climate. So a 40w kiosk open 8 hours per day would probably need in the
> neighborhood of 100-160w in panels with a good 4 sun-hours daily. This is
> doable on a budget.

right, I was thinking more of a 5W most of the time and <25W while
someone is using it, with a sign saying "push here to start" and that
would wake it form sleep mode.  place is closed at night so it could
power off then.  I'd expect they would be used less than 4 hours total
in any given day and far less on weekdays, and really only on nice
sunny days.  with batteries, a 40W panel ought to handle it, maybe 60W
to be safe.  Batteries would be key, as it would get used more on
weekends, so the batters would have time to come to full charge over a
weeks time.