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How can a speed bump harvest electricity?

Other Electricity Harvesting Technologies

In the United Kingdom, some grocery stores have implemented the kinetic plate technology into their facilities Customers drive over the plates in the parking lot and the plates drive a generator that creates 30 kilowatts of power an hour [source: Chapa]. The store then uses the extra power to run their checkout equipment.

But aside from specially designed speed bumps that can extract energy from slow-moving vehicles, other technologies have recently been developed that are trying to harness wasted energy, although through different means.

In 2008, a group of students from the Massachusetts Institute of Technology developed a shock absorber that generates electricity each time a vehicle drives over bumps or potholes in the road. When a vehicle fitted with the shock absorbers goes over a bump, it forces fluid through a turbine attached to a generator. The spinning turbine and generator create electricity and then send it to a battery for storage. This system can increase a vehicle's fuel efficiency by up to 10 percent [source: Chandler].

The energy-producing shock absorbers work best on heavy-duty trucks, with a 6-shock truck being able to produce 1 kilowatt on average, per shock on normal road conditions [source: Chandler]. This amount of power would allow heavy vehicles to use power generated solely from the shock absorbers, without the help of an alternator, and could even produce enough power to run accessory devices.

This shock absorber technology differs from kinetic plates by taking the electricity produced by the vehicle and channeling it back into the vehicle, rather than to a fixed device. Sending the energy back to the vehicle may be a more efficient way of using the wasted energy, at least until energy extracted from speed bumps can be stored easily and transferred to devices or power management systems effectively.

For more information about harvesting energy from the road surface and other related topics, follow the links on the next page.

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