[OLPC_Boston] OLPC Talk: Hand Crank Tiring? It's a Solar Project! (Sunday April 4th, 4PM in Boston)

Holt holt at laptop.org
Fri Apr 2 02:13:06 EDT 2010

Expert Discussion:

    Powering OLPC's XO Laptops using Solar Electricity

Please come in person this (Easter) Sunday April 4th, 4PM Boston Time,
to Kendall Square in Cambridge, Massachusetts, armed with your most
thoughtful questions on Solar practicalities -- as they relate to OLPC
deployment around our fragile planet's rural/developing expanses.

A warm welcome to our guest speakers:

  * Richard Smith, OLPC lead power engineer
  * Robert Pilawa, MIT solar researcher
  * Kim Quirk, NH solar engineer and vendor (attendance tentative)
RICHARD SMITH: I'm going to give a summary of whats going on past and
present with the XO-1 and XO-1.5 with respect to solar, and then mention
what the current options are for the simple case of a XO and a [solar] 

I'll talk about the 10 Watt panel and the voltage limiter option, and 
mention a project in the works with RCAL [Arkansas/California Company]
for a single charger that can be powered from solar panel or a 12V supply.

ROBERT PILAWA: What I would like to talk about is a low-cost solar charger
that we are designing for the developing world. It is compatible with the
OLPC 10W panel (as well as a wide variety of other solar panels), and can
be used to charge lead-acid batteries, cell-phones, and the XO. In
particular, it uses maximum power point tracking (MPPT), which ensures
that the full available power from the panel is used (the typical low-cost
charge controllers used today can waste as much as 30% of the available
panel power). The currently available commercial charge controllers with
MPPT price out at close to $200. Thanks to some innovative new technology,
as well as a focus on cost, we're targeting a final price of below $20 for
our charge controller. I'll discuss some usage scenarios, as it pertains
to the XO and off-grid locations.

KIM QUIRK: If I can't attend [or call in] I would be happy to read the
minutes or address any specific questions that might benefit from the
perspective of a small renewable energy business in the US. There are a
number of do-it-yourself sites to explain inexpensive ways to build solar
modules and hook up to whatever batteries you can find. The solar
charging mechanism is a little harder to just find in-house or build
yourself... but it is important if you want to get the most life out of your

If I do make it I would be happy to talk about the two projects I've
been involved in recently relating to solar power in developing countries --
specifically a local school here (New Hampshire) that is doing a solar
powered refrigeration system for a town in Peru; and the discussions
that Nancie [Severs] and I had for her trip to Vietnam:


    1 Cambridge Center (MEET 4PM SHARP)
    Cambridge, Massachusetts 02142


    Requires Advance RSVP -- thanks!


    http://forum.laptop.org/chat  (that's #olpc-help)

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