Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


ORNL energy harvesters transform waste into electricity

Billions of dollars lost each year as waste heat from industrial processes can be converted into electricity with a technology being developed at the Department of Energy's Oak Ridge National Laboratory.

The high-efficiency thermal waste heat energy converter actively cools electronic devices, photovoltaic cells, computers and large waste heat-producing systems while generating electricity, according to Scott Hunter, who leads the development team. The potential for energy savings is enormous.

"In the United States, more than 50 percent of the energy generated annually from all sources is lost as waste heat," Hunter said, "so this actually presents us with a great opportunity to save industry money through increased process efficiencies and reduced fuel costs while reducing greenhouse gas emissions."

Initially, Hunter envisions the technology being used for cooling high-performance computer chips, thereby helping to solve an enormous problem facing manufacturers of petaflop-scale computers. These mega machines generate massive amounts of heat that must be removed, and the more efficient the process the better. Turning some of that heat into electricity is an added bonus.

Hunter's technology uses cantilever structures that are about 1 millimeter square in size. About 1,000 of these energy converters can be attached to a 1-inch square surface such as a computer chip, concentrated photovoltaic cell or other devices that generate heat. Although the amount of electricity each device can generate is small – 1 to 10 milliwatts per device – many arrays of these devices can be used to generate sizable amounts of electricity that can power remote sensor systems or assist in the active cooling of the heat generating device, reducing cooling demands.

The underlying concept, pyroelectricity, is based on the use of pyroelectric materials, some of which have been known for centuries. First attempts to use this technology to generate electricity began several decades ago, but these studies have been plagued by low thermal to electricity conversion efficiencies – from about 1 to 5 percent.

This is also the case for techniques using thermoelectric, piezoelectric and conventional pyroelectric platforms. However, using arrays of cantilevered energy converters that feature fast response and cycle times, Hunter's team expects to achieve efficiencies of 10 to 30 percent – depending on the temperature of the waste heat generator – in an inexpensive platform that can be fabricated using standard semiconductor manufacturing technology.

"The fast rate of exchange in the temperature across the pyroelectric material is the key to the energy conversion efficiency and high electrical power generation," Hunter said, adding that ORNL's energy scavenger technology is able to generate electrical energy from thermal waste streams with temperature gradients of just a few degrees up to several hundred degrees.

The device is based on an energy harvesting system that features a micro-electro-mechanical, or MEMS, pyroelectric capacitor structure that when heated and cooled causes current to flow in alternate directions, which can be used to generate electricity. In this configuration, cantilevers are attached to an anchor that is affixed to a waste heat generator substrate. As this substrate becomes hot, the cantilever also heats and bends because of the bi-material effect, similar in principle to the bimetal switch used in room and oven thermostats.

"The tip of the hot cantilever comes into contact with a cold surface, the heat sink, where it rapidly loses its heat, causing the cantilever to move back and make contact with the hot surface," Hunter said. "The cantilever then cools and cycles back to the cold heat sink.

"The cantilever continues to oscillate between the heat source and heat sink as long as the temperature difference is maintained between the hot and cold surfaces."

Other developers of this technology, which is funded by the Laboratory Directed Research and Development program, are Nickolay Lavrik, Thirumalesh Bannuru, Salwa Mostafa, Slo Rajic and Panos Datskos. UT-Battelle manages ORNL for DOE's Office of Science.

NOTE TO EDITORS: You may read other press releases from Oak Ridge National Laboratory or learn more about the lab at Additional information about ORNL is available at the sites below:

Twitter -

RSS Feeds -

Flickr -

YouTube -

LinkedIn -

Facebook -

Ron Walli | EurekAlert!
Further information:

More articles from Power and Electrical Engineering:

nachricht Solid progress in carbon capture
27.10.2016 | King Abdullah University of Science & Technology (KAUST)

nachricht Greater Range and Longer Lifetime
26.10.2016 | Technologie Lizenz-Büro (TLB) der Baden-Württembergischen Hochschulen GmbH

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

'Neighbor maps' reveal the genome's 3-D shape

27.10.2016 | Life Sciences

Gene therapy shows promise for treating Niemann-Pick disease type C1

27.10.2016 | Life Sciences

Solid progress in carbon capture

27.10.2016 | Power and Electrical Engineering

More VideoLinks >>>