Subscribe free to our newsletters via your
. 24/7 Space News .




Subscribe free to our newsletters via your




















TECH SPACE
Cooling roofs and other structures with no energy
by Staff Writers
Boulder CO (SPX) Feb 10, 2017


During field tests in Boulder, Colorado and Cave Creek, Arizona, the metamaterial successfully demonstrated its average radiative cooling power larger than 110W/m2 for continuous 72 hours and larger than 90W/m2 in direct, noon-time sunlight. That cooling power is roughly equivalent to the electricity generated using solar cells for similar area, but the radiative cooling has the advantage of continuous running both day and night.

A team of University of Colorado Boulder engineers has developed a scalable manufactured metamaterial - an engineered material with extraordinary properties not found in nature - to act as a kind of air conditioning system for structures. It has the ability to cool objects even under direct sunlight with zero energy and water consumption.

When applied to a surface, the metamaterial film cools the object underneath by efficiently reflecting incoming solar energy back into space while simultaneously allowing the surface to shed its own heat in the form of infrared thermal radiation.

The new material, which is described in the journal Science, could provide an eco-friendly means of supplementary cooling for thermoelectric power plants, which currently require large amounts of water and electricity to maintain the operating temperatures of their machinery.

The researchers' glass-polymer hybrid material measures just 50 micrometers thick - slightly thicker than the aluminum foil found in a kitchen - and can be manufactured economically on rolls, making it a potentially viable large-scale technology for both residential and commercial applications.

"We feel that this low-cost manufacturing process will be transformative for real-world applications of this radiative cooling technology," said Xiaobo Yin, co-director of the research and an assistant professor who holds dual appointments in CU Boulder's Department of Mechanical Engineering and the Materials Science and Engineering Program. Yin received DARPA's Young Faculty Award in 2015.

The material takes advantage of passive radiative cooling, the process by which objects naturally shed heat in the form of infrared radiation, without consuming energy. Thermal radiation provides some natural nighttime cooling and is used for residential cooling in some areas, but daytime cooling has historically been more of a challenge. For a structure exposed to sunlight, even a small amount of directly-absorbed solar energy is enough to negate passive radiation.

The challenge for the CU Boulder researchers, then, was to create a material that could provide a one-two punch: reflect any incoming solar rays back into the atmosphere while still providing a means of escape for infrared radiation. To solve this, the researchers embedded visibly-scattering but infrared-radiant glass microspheres into a polymer film. They then added a thin silver coating underneath in order to achieve maximum spectral reflectance.

"Both the glass-polymer metamaterial formation and the silver coating are manufactured at scale on roll-to-roll processes," added Ronggui Yang, also a professor of mechanical engineering and a Fellow of the American Society of Mechanical Engineers.

During field tests in Boulder, Colorado and Cave Creek, Arizona, the metamaterial successfully demonstrated its average radiative cooling power larger than 110W/m2 for continuous 72 hours and larger than 90W/m2 in direct, noon-time sunlight. That cooling power is roughly equivalent to the electricity generated using solar cells for similar area, but the radiative cooling has the advantage of continuous running both day and night.

"Just 10 to 20 square meters of this material on the rooftop could nicely cool down a single-family house in summer," said Gang Tan, an associate professor in the University of Wyoming's Department of Civil and Architectural Engineering and a co-author of the paper.

In addition to being useful for cooling of buildings and power plants, the material could also help improve the efficiency and lifetime of solar panels. In direct sunlight, panels can overheat to temperatures that hamper their ability to convert solar rays into electricity.

"Just by applying this material to the surface of a solar panel, we can cool the panel and recover an additional one to two percent of solar efficiency," said Yin. "That makes a big difference at scale."

The engineers have applied for a patent for the technology and are working with CU Boulder's Technology Transfer Office to explore potential commercial applications. They plan to create a 200-square-meter "cooling farm" prototype in Boulder in 2017.

The invention is the result of a $3 million grant awarded in 2015 to Yang, Yin and Tang by the Energy Department's Advanced Research Projects Agency-Energy (ARPA-E).

"The key advantage of this technology is that it works 24/7 with no electricity or water usage," said Yang "We're excited about the opportunity to explore potential uses in the power industry, aerospace, agriculture and more."


Comment on this article using your Disqus, Facebook, Google or Twitter login.

.


Related Links
University of Colorado at Boulder
Space Technology News - Applications and Research






Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
TECH SPACE
Penn researchers are among the first to grow a versatile 2-dimensional material
Philadelphia PA (SPX) Feb 17, 2017
University of Pennsylvania researchers are now among the first to produce a single, three-atom-thick layer of a unique two-dimensional material called tungsten ditelluride. Their findings have been published in 2-D Materials. Unlike other two-dimensional materials, scientists believe tungsten ditelluride has what are called topological electronic states. This means that it can have many di ... read more


TECH SPACE
Looking to the future: Russia, US mull post-ISS cooperation in space

Progress Underway for First Commercial Airlock on Space Station

A new recruit for ESA's astronaut corps

The Outer Space Treaty has been remarkably successful - but is it fit for the modern age?

TECH SPACE
Airbus Safran Launchers: 77th consecutive successful launch for Ariane 5

India puts record 104 satellites into orbit

SpaceX Falcon 9 rocket vertical at Florida's Kennedy Space Center

India to launch record 104 satellites next week

TECH SPACE
ISRO saves its Mars mission spacecraft from eclipse

Mars Reconnaissance Orbiter plays crucial role in search for landing sites

Angling up for Mars science

Swirling spirals at the north pole of Mars

TECH SPACE
China looks to Mars, Jupiter exploration

China's first cargo spacecraft to leave factory

China launches commercial rocket mission Kuaizhou-1A

China Space Plan to Develop "Strength and Size"

TECH SPACE
NASA seeks partnerships with US companies to advance commercial space technologies

A New Space Paradigm

Why it's time for Australia to launch its own space agency

Government announces boost for UK commercial space sector

TECH SPACE
Terahertz chips a new way of seeing through matter

Cooling roofs and other structures with no energy

Researchers engineer thubber a stretchable rubber that packs a thermal conductive punch

Penn researchers are among the first to grow a versatile 2-dimensional material

TECH SPACE
NASA finds planets of red dwarf stars may face oxygen loss in habitable zones

Dwarf star 200 light years away contains life's building blocks

Santa Fe Institute researchers look for life's lower limits

Dedicated Planet Imager Opens Its Eyes to Other Worlds

TECH SPACE
NASA receives science report on Europa lander concept

New Horizons Refines Course for Next Flyby

It's Never 'Groundhog Day' at Jupiter

Public to Choose Jupiter Picture Sites for NASA Juno




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News








The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement