National Lab Produces Highly Efficient Waste Heat Generators
May 17, 2011 12:20 PM
comment(s) - last by
The Oak Ridge National Laboratory waste heat generator relies on thousands of tiny piezoelectric cantilevers, similar to this one, produced at the École Polytechnique Fédérale de Lausanne (EFPL).
Tiny cantilever generators could recycle as much as 30 percent of the heat chips put off
Oak Ridge National Laboratory
located about 23 miles south west of Knoxville, Tennessee has a storied history as the home of the Manhattan Project and birthplace of the atomic bomb. Today it has its sights set on many more tiny objectives, only this time it hopes to provide the world with cleaner energy, rather than destructive power.
The scientists at ORNL estimate that billions of dollars is lost every year in waste heat from electronic devices like central processing units (CPUs). Server farms spend millions a year to simply cool down their fields of racked computers. Waste heat is also
a major source of energy loss in automobiles
To that end, a team led by Scott Hunter has
[press release] tiny piezoelectric generators that use a tiny cantilever, approximately 1 mm^2 in size. Approximately 1,000 of these tiny generators can be affixed to a 1 inch^2 CPU. Each tiny generator pumps out 1 to 10 milliwatts -- and together they can produce enough electricity to partially power fans or system sensors.
While that might not sound like much, it's actually significant progress.
long hoped to use piezoeletric generators
to recycle waste heat, but past designs have struggled with efficiencies, only able to convert between 1 and 5 percent of the waste heat to electricity. By contrast Professor Hunter's design has an efficiency of between 10 to 30 percent. The exact efficiency is dependent on the temperature of the waste heat generator (computer chip).
The tiny generator works using widely known physics principles. The tiny cantilever, anchored to the piezoelectric substrate bends due to the bi-material effect when heated. This is the same effect that traditional room thermostats rely upon.
As the cantilever bends it touches the heat sink, cooling it. It then flops back down on the hot surface. This flopping creates vibrations in the piezoelectric material that creates an alternating flow of current, which can be converted to usable DC current.
Describes Professor Hunter, "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. 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."
The key to higher efficiencies was to
pick the right material
and the right physical design. Professor Hunter comments, "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."
This kind of piezoelectric device is part of a growing class of devices known as micro-electrical-mechanical systems (MEMS). Professor Hunter envisions his new MEMS device being installed inside PC and server coolers, saving businesses and home users money on their power bills.
By improving the efficiency of electricity usage, the devices would also reduce fossil fuel usage. Comments Professor Hunter, "In the United States, more than 50 percent of the energy generated annually from all sources is lost as waste heat, 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."
As the device is still pretty expensive, presumably, Professor Hunter is eyeing high-performance systems as the first target for commercial deployment. The tiny generator would allow additional cooling not currently available with a traditional block water-cooled system. By offering greater cooling to the chip, high performance mainframes could be run at higher speeds than ever before, a perfect proving ground for the new MEMS device.
Nickolay Lavrik, Thirumalesh Bannuru, Salwa Mostafa, Slo Rajic and Panos Datskos were among the other researchers who worked on the device for ORNL. The project was the the
Laboratory Directed Research and Development program
under the auspice of the
U.S. Department of Energy
This article is over a month old, voting and posting comments is disabled
5/17/2011 1:41:40 PM
Is there a reason they have to be between the heatsink and the CPU? It seems like these could be attached to a heatsink, allowing the heatsink size (and number of generators) to be as large as necessary without being tied to the size of the CPU die.
5/17/2011 2:40:08 PM
How well they work is dependent on the temperature gradient. The farther from the heat source you get the less efficient they'll be.
"I'd be pissed too, but you didn't have to go all Minority Report on his ass!" -- Jon Stewart on police raiding Gizmodo editor Jason Chen's home
New Material Can Convert 14 Percent of Waste Heat to Electricity
January 19, 2011, 7:53 PM
Up in Smoke: Germans Develop Exhaust Pipe Power
June 6, 2008, 3:01 PM
Promise of Thermoelectric Materials on the Rebound
November 27, 2007, 2:32 PM
SanDisk Unveils Pricey iXpand USB 2.0/Lightning Drive to Expand iPhone, iPad Storage
November 13, 2014, 2:29 PM
HP's 15.6" Omen Gaming Laptop is Incredibly Thin, Powerful
November 4, 2014, 10:34 AM
Tim Cook Touts Apple’s Product Portfolio, Performance in Letter to Employees
October 21, 2014, 8:05 AM
Lenovo Once Again The Top Global PC Maker, Apple Takes 50% of PC Profits
October 9, 2014, 7:46 AM
It’s Official: HP to Split Into Two Business Units
October 6, 2014, 8:14 AM
Quick Note: HP Plans to Split PC, Enterprise Units
October 5, 2014, 4:31 PM
Most Popular Articles
Wal-Mart: Miss Thanksgiving, Get Xbox One + Master Chief Collection for $299
November 17, 2014, 9:40 PM
Sweden Mulls Labelling "Sexist" Video Games in the Wake of Gamergate
November 17, 2014, 2:00 PM
Nokia Lumia 635 LTE Windows Phone is Only $40 at Best Buy on Black Friday
November 18, 2014, 11:59 AM
It's Official: Twitter is Profitable "Junk"
November 16, 2014, 10:45 PM
Apple Releases OS X 10.10.1 Yosemite, iOS 8.1.1 Updates
November 17, 2014, 1:43 PM
Latest Blog Posts
Costco Gives Employees Thanksgiving Off; Wal-Mart Leads "Black Thursday" Charge
Oct 29, 2014, 9:57 PM
"Bear Selfies" Fad Could Turn Deadly, Warn Nevada Wildlife Officials
Oct 28, 2014, 12:00 PM
The Surface Mini That Was Never Released Gets "Hands On" Treatment
Sep 26, 2014, 8:22 AM
ISIS Imposes Ban on Teaching Evolution in Iraq
Sep 17, 2014, 5:22 PM
Space Terrorism is a Looming Threat For the United States
Apr 23, 2014, 7:47 PM
More Blog Posts
Copyright 2014 DailyTech LLC. -
Terms, Conditions & Privacy Information