Tuesday, July 09, 2013

Solar Power

Many of the places in the world do not have easily accessible electrical power.  That includes much of rural Cambodia and Rwanda.  After much discussions with the NGOs that we worked with, and investigations into possible solutions, we settled on a basic design.  It includes 4 small solar panels that generate sufficient voltage to charge a couple of rechargeable batteries.

We pack the 4 solar panels on one side of a transparent plastic case, and connect it through a circuit to charge the batteries.  The batteries are in turn connected to a bunch of LEDs, on the opposite side of the plastic box.  A sensor detects the orientation of the box.  When the solar panels are facing up, the batteries are charged.  When the box is tilted, the LEDs light up for illumination.  There is no switch to turn it on and off.  It is simply controlled by tilting the box.

One of the practical problems that it solved in having dinner in the dark.  At the Happyland Orphanage in Cambodia, power outages are frequent.  Our solar panel / LED light box proves to be very useful.

We have since developed an alternate design.  The solar panels and the batteries are separated.  The solar panels box can be connected to the battery box to charge the battery.  Then the battery box can be used independently to charge small equipment such as smart phones.  In much of rural Rwanda, where there is simply no electrical supply, the solar power boxes are much appreciated.  We brought 12 sets with us, but that is obviously far from enough.  Now that we know this solution works, we will try to build on it for future projects.

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