element14 energy harvesting road test design challenge – part 2
Challenged with designing a device powered by energy harvesting, even the most experienced of our competitors have faced a huge learning curve. That doesn’t mean they simply gave up, however.
Instead, they’ve put in the hours around the clock, in some cases repeatedly going back to the drawing board until they reached the perfect solution. Now, as they fine-tune their projects ahead of the much-anticipated final judging process, here’s an overview of how the projects have developed.
Electrical engineer Victor Sluiter had explored the possibility of developing an egg timer gadget, harvesting energy from immediate water temperature to generate energy and calculate the time needed to cook an egg. The last few weeks have seen this develop substantially, with Victor’s focus evolving from designing a convenient cooking assistant to a potentially life-saving food safety device.
His idea of developing an egg timer gadget hit difficulties when he discovered that in heating up water, both sides of a Peltier element will quickly reach the same temperature, cancelling out the potential for energy harvesting.
Not disheartened, Victor switched tactics and opted to mount the energy harvesting kit inside a pan lid. Victor’s new approach sees energy harvesting used to determine the hardness of the egg, which he believes (on a larger scale) could be developed into food safety initiatives in areas with no available electricity or stable energy sources. ,
Equipping himself with a thermometer and EFM32 microcontroller to programme his temperature monitoring calculations, Victor theorised that energy will be generated by the temperature difference between the inside and outside of the pan and used this to measure the water temperature. This information can then be used to calculate the temperature of the egg as it’s added to the water.
Victor believes this could be ideal for monitoring and controlling processes, where temperature or pressure control is required, but no electricity is available (such as natural disaster areas and refugee camps).
Victor demonstrates the sheer amount of kit involved in his eggstensive trials
Meanwhile, Wojciech Gelmunda’s carbon monoxide monitor has continued to progress, having evolved his design to take advantage of the warm water supply in kitchens and bathrooms. His initial tests had suggested this alternative approach could prove successful in utilising temperature differences, with the EFM32 microcontroller gathering and maintaining energy from the excess heat of hot water pipes.
In setting up an application to detect carbon monoxide, Wojciech selected the TGS 5042 from Figaro. As an electrochemical sensor, it does not need a power supply, instead it is filled with chemicals which react with carbon monoxide, with the sensor working as a current source. Additionally, other gases and temperature have minimal influence on it, and with a minimum lifespan of 7 years, it’s an ideal solution that doesn’t rely on batteries.
Of course, in testing a carbon monoxide detector, Wojciech had to find a way to recreate CO2 in his home without risking CO2 poisoning. The solution? Simply conducting the experiment inside a closed jar.
Wojciech sets up his carbon monoxide detector trials
As discussed in previous updates, while these projects are small in scale, the progress and lessons can easily be amplified into bigger applications and the impressive breakthroughs and Eureka moments cannot be ignored.
As our challengers have noted during their extensive research and travels over the last few months, energy harvesting solutions are becoming increasingly prevalent in a range of large scale applications.
Monte Chan spotted this car park utilising solar power on his travels
Despite this, such applications remain on the periphery of our everyday lives in a support function, while the devices and tools we rely on continue to predominantly run from finite energy sources. The process of overcoming this started years ago, and for all the progress that’s been made, the journey is only just beginning.
I can’t help but feel that the individual journeys undertaken by our competitors represent a serious piece of progress. There’s been a feeling of real significance in watching as these hobbyists have tackled complicated engineering challenges and refused to accept defeat and hopefully this will prove to be inspirational for design engineers at all levels.
Thanks to their efforts, we’re also a huge step closer to seeing energy harvesting applied to a mainstream device with the potential to replace conventional battery power. Regardless of the outcome of the upcoming judging process, the concept of replacing battery and mains powered devices with those fuelled by power sourced from energy harvesting suddenly seems so much closer to reality.
Check out the first part of this energy harvesting challenge
The Design Challenge Participants are still open to support, discussion and encouragement. Join in the discussion and add your ideas and questions: https://www.element14.com/community/groups/energy-harvesting-solutions
About the author:
Dianne Kibbey is Global Head of Community at element14 – www.element14.com
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