The performance of energy scavenging devices can now be measured more accurately than ever thanks to new tools unveiled today.
Energy harvesting (EH) devices, which collect ambient energy from the environment around them to use as a power source, are predicted to become a multi-billion pound industry as energy becomes scarcer, with applications in wearable electronics, automotive engine monitoring systems and even the move to the Internet-of-things.
But a lack of accurate and standardised measurement in the market means developers have been unable to provide certainty to the market on the power output they can deliver and prevent uncertainty in performance claims harming confidence in the technology.
Today, The Metrology for Energy Harvesting Project, a three-year collaboration between seven European research institutes, concludes in Germany hoping to overcome this problem.
Dr Paul Weaver, of the National Physical Laboratory, which was one of the partners in the project, said: “The lack of accurate and standardised measurement in energy harvesting is hindering the development, innovation and market acceptance of these devices as well as efforts to improve efficient use of waste energy in industry and commercial products.
“The work we present today will enable industry and consumers to reliably assess different EH technologies such as thermoelectric and vibrational harvesting devices.
“These developments will increase market confidence helping to secure wider industrial investment. More accurate and standardised measurement will allow industry to lower costs and increased energy efficiency to make a stronger business case for applications in new sectors.”
The report Energy Harvesting: A metrological approach will be presented at Physikalisch-Technische Bundesanstalt in Braunschweig this morning as a conclusion to the project.
The research was established in 2009 as part of the European Metrology Research Programme (EMRP) to combine Europe's expertise in measurement, energy harvesting materials and systems engineering to address this issue through thoroughly researched, rigorous and traceable measurement techniques.
The highlights of the work revealed today include new techniques and models to deliver the maximum power output for piezoelectric and other electro-mechanical energy harvesters. This work addressed not only how to make the measurement, but also which measurements are required to make a realistic assessment of performance in widely varying applications.
Techniques for measuring energy coupling at the microscale and the power requirements and outputs of Microelectromechanical systems (MEMS) devices, will also be revealed, as will tools and models to measure electrical and thermal properties of nanomaterial harvesters and their coupling down to the nanoscale.
The research revealed today also include the first reference materials for measuring induced electric voltage within thermometric materials in response to temperature differences with temperature ranges up to 860K, addressing increasing market pressure for harvesters that work in more harsh or extreme environments such as in car engines.
And a test-rig able to measure the performance of magnetostrictive devices – a new class of energy harvesters based on magnetostrictive materials that exhibit changes in structure as a result of changes in the magnetic properties of the environment they are exposed to – will also be unveiled.
The project is now planning a new stream of work to deepen and broaden its research in energy harvesting. More details on The Metrology for Energy Harvesting Project’s results can be found here.