BBC News/Matt McGrath: Climate change: Low cost, low energy cooling system shows promise

Climate change: Low cost, low energy cooling system shows promise
By Matt McGrath Environment correspondent

    26 October 2018

    Share

Image copyright Yang Lab / University of Colorado Boulder
Image caption The roof array that can cool a house with little energy use

Researchers in the US have scaled up a new low-cost system that could provide efficient cooling for homes while using very little electricity.

The team has developed a roof-top sized array, built from a highly reflective material made from glass and polymers.

In tests, the system kept water around 10C cooler than the ambient air when exposed to midday sunlight in summer.

The approach could also be scaled up to cool power stations and data centres.

The system is based around what's termed a cooling meta-material, which is essentially an engineered film not found in nature.

Last year, researchers at CU Boulder in the US published research on the extraordinary properties of the new film, which reflects back almost all incoming light from the Sun.

    Splosh! How to make a giant impact crater
    Clever crows reveal window into the mind

But it also has another cooling trick that makes it quite special. If you use the film to cover water, it allows any heat in the liquid to escape into the air.

So when the heat escapes and is not replaced because the material deflects away sunlight, temperatures drop rapidly.

Now the scientists have improved the system and and built and tested a 13-sq-metre array of panels, that's small enough to fit on most rooftops.

"You could place these panels on the roof of a single-family home and satisfy its cooling requirements," said Dongliang Zhao, lead author of the study from CU Boulder's Department of Mechanical Engineering.
How effective is this material?
Image caption The new material looks like aluminium foil but is slightly thicker

The system has been tested outdoors in a variety of weather conditions. In experiments carried out in the summer of 2017, the reflective system kept a container of water some 12C cooler than the surrounding air in the warmest hours of the day.

"We can now apply these materials on building rooftops, and even build large-scale water cooling systems with significant advantages over the conventional air-conditioning systems, which require high amounts of electricity to function," said Associate Professor Gang Tan, another author of the study from the University of Wyoming.
What makes it work?

The key material is made with glass microspheres embedded into a polymer film, with a thin silver coating.

At just 50 micrometres, it is slightly thicker than aluminium foil.

Another big advantage of the material is that it can be manufactured on rolls, making it easier to apply on residential and commercial applications.
What is it likely to be used for?
Image caption The film can be manufactured cheaply say the authors

The authors say that one of the most effective uses of the new material would be to cool thermoelectric power generating plants. These installations use large amounts of water and electricity to maintain the operating temperatures of their machinery. Using the new material could make them more efficient.
How much cooling does the world need?

In 2016 around 10% of the world's energy use went to power air conditioning. The International Energy Agency says that this rate is set to triple by 2050, with air conditioning (AC) consuming as much electricity as is used in China today.

As well as all the CO2 that is produced as electricity is created to power these devices, AC units also contain potent greenhouse gases in the form of hydrofluorocarbons.

HFCs were introduced to protect the ozone layer, because the previous generation of the cooling chemicals exacerbated the hole over Antarctica that had developed in the 1980s.

While HFCs are less damaging, they have a large global warming potential. In 2016, countries agreed that they would be phased out over the course of the next 15-20 years. If this happens successfully it could have a significant impact on limiting future temperature rises.

The new study has been published in the journal Joule.
Related Topics

    Climate change

Share this story About sharing

    Email
    Facebook
    Messenger
    Twitter
    Pinterest
    LinkedIn

More Videos from the BBC

Story of Nellie's tree lives on
WW2 Dunkirk shed door veteran turns 100

    Could you give up fast fashion?

'Multiple casualties' in synagogue shooting
Breaking the 'impasse'

    Does NHS provide diabetic monitor the PM uses?

Recommended by Outbrain
Elsewhere on BBC

    BBC.com Is personal enrichment the new pinnacle of luxury?

    BBC News MPs back action against rogue landlords

    BBC News Merkel facing double trouble in German vote

Recommended by Outbrain
You Might Also Like

    BBC Future One country's plan to solve the world's hidden health crisis

From Around the Web

10 Big Tech Stocks That Are Surprising Bargains Right Now Trendingstock Today
Asia drives growth as global air travelers seen doubling to 8.2bn by… Nikkei Asian Review
SGX rides derivatives boom as listings stagnate Nikkei Asian Review
These Cars Will Last 250,000 Miles - Is Yours On This List? Buzzdrives.com
Ma Ke: Spreading Love Through Fashion CGTN

    New Site Finds the Cheapest Flights in Seconds! TripsShop.com

Promoted content by Outbrain
Top Stories
Passenger plane crashes in sea off Jakarta

The Boeing 737, carrying 189 people, vanished shortly after taking off from the Indonesian capital.
29 October 2018
Far-right Bolsonaro is Brazil's new leader
29 October 2018
Jubilation and despair after Brazil poll
29 October 2018
Features
‘The SOS in my Halloween decorations’
Five things to know for the week ahead
The year's best astronomy photos
What are Jair Bolsonaro's policies?
Why Cape Town's trains are on fire
Video
What is driving Americans to vote?
What we know about the Pittsburgh shooting
The women looking outside the law for abortions
'My viral obituary for my sister'
Elsewhere on the BBC
Lyrics quiz

Have you been getting these songs wrong?
Full article Lyrics quiz
Feeling hot

What happens to your body in extreme heat?
Full article Feeling hot
Ads by Google
Why you can trust BBC News
BBC News Services

    On your mobile
    On your connected tv
    Get news alerts
    Contact BBC News

Explore the BBC

    Home
    News
    Sport
    Weather
    Shop
    Reel
    Travel
    Capital
    Culture
    Future
    Sounds
    CBBC
    CBeebies
    Food
    Bitesize
    Arts
    Make It Digital
    Taster
    Nature
    Local
    TV
    Radio

    Terms of Use
    About the BBC
    Privacy Policy
    Cookies
    Accessibility Help
    Parental Guidance
    Contact the BBC
    Get Personalised Newsletters
    Advertise with us
    Ad choices

Copyright © 2018 BBC. The BBC is not responsible for the content of external sites. Read about our approach to external linking.