Power from the rain
20 February 2008
News
Information from Frost & Sullivan Technical Insights
As wireless devices and electronic sensors become ever smaller and more distributed, developers are increasingly searching for ways to harvest energy from the environment to reduce the need for power connections or batteries.
In recent months, several groups have explored using micro-electromechanical systems (MEMS), piezoelectric systems to harvest energy from acoustic vibrations.
Other researchers are looking into thermoelectrics or miniaturised photovoltaics. Frost & Sullivan has however taken particular notice of a team of researchers in France that proposed a new source of environmental energy - falling raindrops - in the journal 'Smart Materials and Structures'. "Our system scavenges the vibration energy from a piezoelectric flexible structure impacted by a water drop," explained Thomas Jager, one of the authors of the report.
In the device, strips of a piezoelectric ribbon are suspended across a gap. When a drop of water splashes onto the band of material, it vibrates, creating a small amount of electrical energy in the piezoelectric material. "It appears that to effectively recover energy from raindrops using piezoelectricity, the material used must be very thin, not pre-stressed, and with a width slightly smaller than the maximum diameter of the impacting drop," Jager said. The strips should also be completely covered with conducting electrodes to yield the maximum effect.
The researchers found that about 1 nJ of electrical energy and 1 μW of instantaneous power could be recovered using raindrops. "This is the worst-case scenario, as simulations show that it would be possible to recover 25 microjoules and 12 milliwatts from a downpour drop," Jager explained.
Raindrops in a downpour are larger in size and fall more rapidly, delivering greater kinetic energy to the piezoelectric band. The researchers are now working to determine the effect that different kinds of dropping action have on the power generated, as they believe that 'splashing' could reduce the power available to the system. They are also exploring ways to conveniently store the electrical power produced by such a system to allow a device to make use of energy from multiple raindrops.
For more information contact Patrick Cairns, Frost & Sullivan, +27 (0)21 680 3274, patrick.cairns@frost.com
Further reading:
Personality profile: Jean Mearns
29 July 2020, WH Circuit
, News
“No one works for me, they only work with me, for without each other our team will fail to exceed the expectations of our customers.”
Read more...
Letter to the editor
29 July 2020
, News
I take exception to the article ‘To fake or not to fake’ published in the June edition of Dataweek that is clearly based on the principle ‘guilty until proven innocent’.
I am by no means an expert
...
Read more...
Q&A with Brandon Kuhn and Steve Stafford
29 July 2020
, News
Q: What is the rationale behind the reorganisation? What impact will it have on Avnet’s customers in South Africa? A (Kuhn): Since 2009, our shared front-end model in South Africa has differed from the
...
Read more...
Avnet EMEA names two new leaders to SA operation
29 July 2020
, News
Avnet has named Steve Stafford and Brandon Kuhn as new leaders in South Africa following the completion of a reorganisation in the region.
Read more...
UCT chooses Tektronix instruments for training lab
29 July 2020, Comtest
, News
Comtest, local partner to Tektronix, recently assisted the University of Cape Town (UCT) physics department in refurbishing its electrical training laboratory. All of the existing analog oscilloscopes
...
Read more...
New electromagnetic solutions range from Accutronics
29 July 2020, Accutronics
, News
Accutronics has been appointed as the reseller for the Electromagnetic Integrated Solutions (EIS) range of products from API Technologies.
APITech offers a complete line of coaxial EMI solutions,
...
Read more...
Fighting COVID-19 using TV white space spectrum
29 July 2020
, News
The CSIR has partnered with the Technology Innovation Agency (TIA) to enable local Internet service providers to deploy Television White Space (TVWS) networks, using the CSIR-developed Secondary Geo-Location
...
Read more...
Clearing the Static: ESD wrist straps
29 July 2020, Actum Electronics
, News
The human body is the primary source of electrostatic charge generation. In order to control and reduce static charge build-up and prevent electrostatic discharges (ESD), we use grounding systems to ensure
...
Read more...
From the editor's desk: This too shall pass
29 July 2020, Technews Publishing
, News
Things were tough enough for the South African electronics manufacturing industry before, but this year has thrown up unprecedented challenges that nobody could have foreseen and which are outside of
...
Read more...
Electronics news digest
29 July 2020
, News
South Africa
• As part of the national data-driven approach to countering COVID-19, the CSIR has developed a platform that monitors human mobility to better understand movement patterns across specific
...
Read more...
printer friendly version