The Green Wheel, developed by the Smart Cites group at the Media Lab, is a self-contained unit that includes an electric motor and battery, along with a generator that can recharge the battery. With a wirelessly operated throttle, the generator can release energy stored in braking to support pedaling during more difficult stretches. While the concept of bikes that can recycle their own energy and even make small contributions to the grid provides numerous opportunities, the Green Wheel project is not limited to power microgeneration.
The Mobile Experience Lab combined the hardware with innovative software and electronics to create a new platform for sustainable mobility.
Combined with a GPS-enabled wireless device and appropriate software, the Green Wheel system can combine with ubiquitous computing to form an integral part of a smart city. For example, bikes outfitted with the Green Wheel and a mobile device can create a network of distributed urban sensors, collecting data on road conditions, sound pollution, and mobility patterns using the mobile device's accelerometer, microphone, and GPS. Sensors on the handlebars can collect data on air quality. A dedicated Web service can aggregate the data in real-time, providing an easy way to measure a city's "health signs."
Peer to peer shipping is another exciting application of the Green Wheel technology. People biking in the city could elect to participate in an ad-hoc bike-messenger service. A biker would receive a message from the Web service that someone across town has just bought an item online and would like it delivered. To earn a quick fee, the rider could go to the vendor's location, pick up the item, and deliver it to the customer. The MIT Mobile Experience Lab has developed many such scenarios for how Green Wheel bikes could help to turn a regular city into a smart city.