Technology update: Alternative power sources for instrumentation

Energy scavenging or harvesting methods are becoming more mainstream for low-power instrumentation. Can you use them? At Sensors Expo 2009, energy harvesting took the limelight, using vibration, light, heat, or even radio frequency. Batteries and power management remain important.

06/17/2009


Each year at the Sensors Expo, some technology seems to take the limelight. In recent years it’s been wireless, but in 2009 it was energy harvesting. You probably know what this is about if you have been considering adding wireless instrumentation to your plant. Devices that have no wires to carry data probably have no wires to carry power either, so they depend on self-contained sources. The number of options is growing.

Batteries are an obvious choice, and in many situations they still represent a simple low-cost solution with a proven track record. Non-recharging lithium thionyl chloride battery chemistries can operate for 5, 10, or even 20 years when sized appropriately for the application. Companies such as Tadiran and Xeno Energy offer wide selections of industrial batteries using this long-life technology.

Read more on understanding .

Read more on instrumentation powering options .

Even if batteries will last until after you retire, they do go dead eventually. So some users want other technologies to capture the energy available in typical plant environments. Some energy sources are natural, like wind and sun. Others depend on working equipment, like heat, vibration, and even radio waves. Energy harvesting technologies, such as wind and photovoltaic cells, are available in large versions of course. But, for this discussion, we’re talking about very small amounts of power, typically on the order of a few milliwatts, and in some cases, microwatts.

Vibration driven sensors are becoming more common and are available from companies like AdaptivEnergy , Perpetuum , Cerametrics , Cymbet , and KCF Technologies . This is a growing field that includes multiple sub-technologies. Some generators need to operate at a specific vibration frequency, such as 50 or 60 Hz. Others can operate at any frequency. Since output depends on specific conditions, this approach will likely require experimentation. One appealing element of vibration is that it is a continuous supply, as long as the source device is running.

Tiny wind turbines can also deliver power, but like their larger counterparts, they only work when the wind is blowing. Most of these small units need very little wind to operate, but they will probably need protection from the elements. Cymbet and KCF Technologies both offer units.


Cymbet EnerChip EH Solar Energy Harvesting module is the heart of the new Texas Instruments eZ430-RF2500-SEH Wireless Demo Kit. This kit is the world's first complete autonomous Energy Harvesting wireless sensor development tool, Cymbet says.

Photovoltaic cells are made in all shapes and sizes, including tiny units that are around 1 sq. in. These don’t always need to be in direct sunlight but can operate off of artificial sources as well. Given the variety of options, you can get just about any combination of voltage and current you need. Cymbet and KCF Technologies both offer miniature photovoltaic units.

Heat energy scavenging is still developing, but there were units shown by Cymbet and KCF Technologies . One of the difficulties with this approach is creating a large enough temperature differential within the device to be effective. KCF’s unit has a small fan to help dissipate heat, so the generator has to power that as well as the driven device.

Powercast is sending power to devices via RF transmissions, allowing the sensor to collect energy through an antenna. (The company has managed to capture energy from ambient cell phone transmissions, but this typically isn’t enough to be useful.) One 3-watt transmitter can send power to a number of devices, although the distance is limited. The greater the distance, the more the usable wattage falls off. This can be improved using directional antennas, but only so far.

All of these technologies can generate power, but their usefulness depends on careful energy management. The companies listed have all developed hardware and protocols to manage power as well as collect it. This is especially important for those methods that are intermittent by nature. Well-thought-out systems typically incorporate some storage mechanism using capacitors or batteries to accumulate unused power and release it when there is a spike in demand. Another method uses a traditional battery as a backup for interruptions in the primary source.

One mechanism for energy storage is new thin-film batteries that use lithium ion technology. Infinite Power Solutions showed a range, with sizes varying from smaller than postage stamps to half of a business card. A typical unit 1 in. square and 7 mils thick can put out 4 V with 0.5 to 1.0 mAh.

These methods combined with very energy-stingy devices makes for high efficiency and deployment flexibility. Still, there is little in the way of standardization, so expect that you’ll have to do some experimentation.

Also see: Sensors Expo photo gallery: Olympic torch, power harvesting , wireless demo.

—Peter Welander, process industries editor, PWelander@cfemedia.com ,
Control Engineering Process Instrumentation & Sensors Monthly
Register here to select your choice of free eNewsletters .





The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by Control Engineering subscribers. Vote now (if qualified)!
The System Integrator Giants program lists the top 100 system integrators among companies listed in CFE Media's Global System Integrator Database.
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
This eGuide illustrates solutions, applications and benefits of machine vision systems.
Learn how to increase device reliability in harsh environments and decrease unplanned system downtime.
This eGuide contains a series of articles and videos that considers theoretical and practical; immediate needs and a look into the future.
Maximize ROI with integrated control system approach; Microcontrollers vs. PLCs; Power quality; Accelerate and rewire IIoT; Traits for excellent engineers
HMI effectiveness; Distributed I/O; Engineers' Choice Award finalists; System Integrator advice; Inside Machines
Women in engineering; Engineering Leaders Under 40; PID benefits and drawbacks; Ladder logic; Cloud computing
Programmable logic controllers (PLCs) represent the logic (decision) part of the control loop of sense, decide, and actuate. As we know, PLCs aren’t the only option for making decisions in a control loop, but they are likely why you’re here.
This digital report explains how plant engineers and subject matter experts (SME) need support for time series data and its many challenges.
This article collection contains several articles on how advancements in vision system designs, computing power, algorithms, optics, and communications are making machine vision more cost effective than ever before.

Find and connect with the most suitable service provider for your unique application. Start searching the Global System Integrator Database Now!

Control room technology innovation; Practical approaches to corrosion protection; Pipeline regulator revises quality programs
Cloud, mobility, and remote operations; SCADA and contextual mobility; Custom UPS empowering a secure pipeline
Infrastructure for natural gas expansion; Artificial lift methods; Disruptive technology and fugitive gas emissions
Automation Engineer; Wood Group
System Integrator; Cross Integrated Systems Group
Jose S. Vasquez, Jr.
Fire & Life Safety Engineer; Technip USA Inc.
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by Control Engineering subscribers. Vote now (if qualified)!
The System Integrator Giants program lists the top 100 system integrators among companies listed in CFE Media's Global System Integrator Database.
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
This eGuide illustrates solutions, applications and benefits of machine vision systems.
Learn how to increase device reliability in harsh environments and decrease unplanned system downtime.
This eGuide contains a series of articles and videos that considers theoretical and practical; immediate needs and a look into the future.
Maximize ROI with integrated control system approach; Microcontrollers vs. PLCs; Power quality; Accelerate and rewire IIoT; Traits for excellent engineers
HMI effectiveness; Distributed I/O; Engineers' Choice Award finalists; System Integrator advice; Inside Machines
Women in engineering; Engineering Leaders Under 40; PID benefits and drawbacks; Ladder logic; Cloud computing
Programmable logic controllers (PLCs) represent the logic (decision) part of the control loop of sense, decide, and actuate. As we know, PLCs aren’t the only option for making decisions in a control loop, but they are likely why you’re here.
This digital report explains how plant engineers and subject matter experts (SME) need support for time series data and its many challenges.
This article collection contains several articles on how advancements in vision system designs, computing power, algorithms, optics, and communications are making machine vision more cost effective than ever before.

Find and connect with the most suitable service provider for your unique application. Start searching the Global System Integrator Database Now!

Control room technology innovation; Practical approaches to corrosion protection; Pipeline regulator revises quality programs
Cloud, mobility, and remote operations; SCADA and contextual mobility; Custom UPS empowering a secure pipeline
Infrastructure for natural gas expansion; Artificial lift methods; Disruptive technology and fugitive gas emissions
Automation Engineer; Wood Group
System Integrator; Cross Integrated Systems Group
Jose S. Vasquez, Jr.
Fire & Life Safety Engineer; Technip USA Inc.
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by Control Engineering subscribers. Vote now (if qualified)!
The System Integrator Giants program lists the top 100 system integrators among companies listed in CFE Media's Global System Integrator Database.
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
This eGuide illustrates solutions, applications and benefits of machine vision systems.
Learn how to increase device reliability in harsh environments and decrease unplanned system downtime.
This eGuide contains a series of articles and videos that considers theoretical and practical; immediate needs and a look into the future.
Maximize ROI with integrated control system approach; Microcontrollers vs. PLCs; Power quality; Accelerate and rewire IIoT; Traits for excellent engineers
HMI effectiveness; Distributed I/O; Engineers' Choice Award finalists; System Integrator advice; Inside Machines
Women in engineering; Engineering Leaders Under 40; PID benefits and drawbacks; Ladder logic; Cloud computing
Programmable logic controllers (PLCs) represent the logic (decision) part of the control loop of sense, decide, and actuate. As we know, PLCs aren’t the only option for making decisions in a control loop, but they are likely why you’re here.
This digital report explains how plant engineers and subject matter experts (SME) need support for time series data and its many challenges.
This article collection contains several articles on how advancements in vision system designs, computing power, algorithms, optics, and communications are making machine vision more cost effective than ever before.

Find and connect with the most suitable service provider for your unique application. Start searching the Global System Integrator Database Now!

Control room technology innovation; Practical approaches to corrosion protection; Pipeline regulator revises quality programs
Cloud, mobility, and remote operations; SCADA and contextual mobility; Custom UPS empowering a secure pipeline
Infrastructure for natural gas expansion; Artificial lift methods; Disruptive technology and fugitive gas emissions
Automation Engineer; Wood Group
System Integrator; Cross Integrated Systems Group
Jose S. Vasquez, Jr.
Fire & Life Safety Engineer; Technip USA Inc.
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
click me