Yep, saw that. I'm unsure of the specific technical reason, but we were advised by the firm managing our solar panel installations to avoid letting extra devices draw a here-and-there type charge from our battery bank. The stated reason was that it would "reduce the life of the system". We were running classrooms full of thin clients off relatively small solar installation, so this issue might have been unique to us.

In a third world nation, a mobile phone battery charging business might generate a few hundred dollars a year, provided you could balance both businesses without one affecting the other. If there is a technical issue with drawing stray charges from the bank, and the batteries themselves cost a few thousand dollars to replace, I'm wondering if it's wise. That said, it's a really clever way to make money and ease sustainability issues with a program like this.

I worked for an NGO in Cambodia (http://www.kapekh.org) that implemented a similar program with thin clients powered by solar panels, but without the cargo container.

The program saw these thin clients installed within high school computer rooms, and had the simple goal of teaching office skills to impoverished high school children. Prior, we had a dozen or so standard computer labs that had endless issues with maintenance, misuse (video games, vcds, etc) and the expense of electricity. Thin clients ended up being way easier all around. Prior to getting USAID funding, we were sourcing them directly from a Chinese vendor.

http://www.youtube.com/watch?v=s7OYQzv75Pk - A video of one of our first labs being opened and an overview of the idea. I believe there are about 20 of these labs now.

One of the issues we found with solar panels and the battery banks was the misuse of electricity perceived as "free". Charging mobile phones using high-end solar panel batteries was an issue, especially when our networking equipment was unplugged to allow for more charging devices.