Pickin' Up Good Vibrations to Produce Green Electricity

Nov 30, 2009
Pickin' Up Good Vibrations to Produce Green Electricity
Good vibrations: the new breed of energy harvester under development in the laboratory.

(PhysOrg.com) -- Vibrations from the environments we live and work in could be much more widely harnessed as a clean source of electricity, due to cutting-edge UK research.

Known as 'energy harvesting', the concept has been around for over a decade, but researchers from the University of Bristol aim to make it possible to make use of a much wider range of vibrations than is currently possible.

It's hoped that within five years 'energy harvesting' could be powering many more of our devices from heart monitors to mobile phones.

The work is funded by the Engineering and Physical Sciences Research Council (EPSRC).

The team are exploring how vibrations caused by machines such as helicopters and trains could be used to produce power. Vibrations from household appliances and the movement of the human body could also be harnessed in this way.

Commercial energy-harvesting devices already exist which, for instance, use vibrations from industrial pumps to power sensors monitoring the pumps' condition.

"Vibration energy-harvesting devices use a spring with a mass on the end", says Dr Stephen Burrow, who is leading the project. "The mass and spring exploit a phenomenon called resonance to amplify small vibrations, enabling useful energy to be extracted. Even just a few milliwatts can power small electronic devices like a heart rate monitor or an engine temperature sensor, but it can also be used to recharge power-hungry devices like or mobile phones."

But existing devices can only exploit vibrations that have a narrow range of frequencies (the frequency is the number of vibrations occurring per second). If the vibrations don't occur at the right frequency, very little power can be produced and it will be too low to be useable. This is a big problem in applications like transport or human movement where the frequency of vibrations change all the time.

However, the Bristol team are developing a new type of device where the mass and spring resonate over a much wider range of frequencies. This would enable a much wider range of vibrations to be exploited and so increase the overall contribution that energy harvesting could make to energy supplies. The team believes it can achieve this by exploiting the properties of non-linear springs which allow the energy harvester to respond to a wider range of frequencies than conventional springs.

Energy harvesters generate low-level power on a similar scale to batteries but without the need for battery replacement or disposal of potentially dangerous and polluting chemicals. They are also suited to applications where hard wiring would be impracticable, vulnerable to damage or difficult to access for maintenance purposes.

Energy harvesters could be used extensively, for example, to provide power for wireless monitoring and diagnostic sensors that generate data on:

  • a person's heart rate, body temperature or blood pressure
  • stresses experienced by engine components, structural elements in buildings etc
  • brake temperatures in railway rolling stock
"There's a huge amount of free, clean energy out there in the form of vibrations that just can't be tapped at the moment," says Dr Burrow. "Wider-frequency energy harvesters could make a valuable contribution to meeting energy needs more efficiently and sustainably."

If the research at Bristol succeeds in achieving its objectives, wider-frequency energy harvesting devices could be available for real-world use within five years.

Source: Engineering and Physical Sciences Research Council (news : web)

Explore further: Blu-ray disc can be used to improve solar cell performance

add to favorites email to friend print save as pdf

Related Stories

Rain Power: Harvesting Energy from the Sky

Jan 22, 2008

Researchers who study energy harvesting see energy all around us – we just need to find a way to capture that energy. One of the latest energy harvesting techniques is converting the mechanical energy from ...

Recommended for you

How polymer banknotes were invented

30 minutes ago

The Reserve Bank of Australia (RBA) and CSIRO's 20-year "bank project" resulted in the introduction of the polymer banknote – the first ever of its kind, and the most secure form of currency in the world. ...

Enabling the hearing impaired to locate human speakers

1 hour ago

New wireless microphones systems developed at EPFL should allow the hearing impaired to aurally identify, even with closed eyes, the location of the person speaking. This new technology will be used in classrooms ...

Researcher explores drone-driven crop management

Nov 25, 2014

A flock of pigeons flies over the soybean field where J. Craig Williams is standing. He reaches down and rips off a brown pod from one of the withered plants and splits it open. Grabbing a tiny bean between ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

drewgrey
not rated yet Nov 30, 2009
What are the limitations of piezo-electric that prevent a solid state (more or less) version of energy harvester? Could a coating be applied to energy transmission lines that would in addition to insulating the wire boost the current passing through it by harvesting the vibration of the lines?
sender
not rated yet Dec 01, 2009
vibrationally sensitive polymers would work a few million times better than a common spring i would imagine.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.