8/8/2006 4:49:52 PM, by Ryan Paul
Green WiFi, a nonprofit organization founded by two Sun Microsystems employees, has big plans for solar-powered WiFi. The organization hopes to bring Internet access to schools in developing countries by building wireless network grids with battery-powered routers connected to solar panels mounted on rooftops.
Funded by MIT's One Laptop Per Child (OLPC) project, Green WiFi has begun development on the initial prototype nodes. The OLPC project pursues the ambitious goal of bringing $100 laptops to students in developing countries. High-profile critics have derided the OLPC project and argued that the value of the system is considerably diminished without access to broadband Internet. Green WiFi solar wireless technology could potentially resolve that issue by bringing free Internet connectivity to regions with poor infrastructure.
Each of the $200 WiFi nodes includes a specialized control mechanism that manages power consumption and can exercise "elegant degredation" to decrease the extent of coverage and reduce accessibility when the battery lacks energy. For instance, when weather conditions are such that the WiFi nodes have limited energy, the nodes could automatically limit access so that connectivity is available only to teachers and students. Green WiFi co-founder Marc Pomerleau comments, "What we bring to the table is an intelligent charge-controller. We put the router on a diet."
Built with a 10-watt Shell ST10 solar panel and a Netgear WGT634U router, Green WiFi's first prototype fared surprisingly well in early tests, providing continuous network access through 28 days of rain. The inexpensive WiFi nodes can be deployed about a kilometer apart, which means that they could potentially provide much-needed last mile coverage to rural areas with limited infrastructure and accessibility.
Although Green WiFi's power modulation technology is very innovative, solar-powered WiFi isn't a new concept. Last year, a company called Lumin helped deploy solar-powered access points in a Boulder, Colarado. Although Lumin's solar WiFi nodes don't use an energy modulation system like the Green WiFi nodes, Lumin's nodes work because the company's highly-sophisticated solar panels are capable of charging in almost any weather conditions and can even draw a charge from moonlight. Specialized solar WiFi access points are also commercially available from IR Data Corporation, and a number of other vendors. Wind-powered WiFi is also appears promising, and is being actively developed by inventor Paul Garrin.
The efficacy of energy-efficient wireless has been proven in numerous testing environments, and Green WiFi hopes that its full-scale pilot project, a mesh network for three schools in Northern India, will further validate the technology.