“What, harnessing the blazing sun for cooling instead of heating?” Leave it to the Israelis!
By David E. Kaplan
An Israeli company, SolCold has developed a new paint that convert sun’s rays into cool air-conditioning. The double-layered nanotech coating is a potentially game-changing electricity-free solution for cooling buildings or equipment in intensely sunny climates. This makes it ideal for Central and South America, the entire Middle East and all of Africa – from Cairo to Cape Town.
How does it work?
SolCold’s unique paint – “no thicker than a business card” – is applied to a surface of an object, where the sun’s radiation triggers a reaction in the material. This reaction then converts the heat accumulated on the object it is applied to – into radiation. This radiation is then emitted in a process called ‘anti-Stokes fluorescence’ – invented by electrical engineer Yaron Shenhav, the co-founder and CEO of SolCold – thus providing the cooling effect.
“SolCold’s material functions as if it were a thin layer of ice that gets thicker and cooler as the sun gets stronger,” explains Shenhav. “We are focusing first on homes and shopping malls, but it can be applied on the roofs of cars and this can help save gasoline.”
“When applied to the rooftops of buildings, the material can help save up to 60% in energy costs,” says Shenhev, “which translates into annual cost savings of +$10,000 per building.” There’s also a major positive impact on the environment – saving on these energy costs means a considerable reduction in CO2 emissions. “We are not just saving costs, but also helping protect our environment at the same time.”
SolCold’s product is generating interest for coating anything from chicken coops to cargo ships, malls to stadiums, cars to planes, satellites to hothouses, military equipment to apartment houses.
How did such an early-stage company receive so much attention already?
SolCold first made the news in June 2016, when it was one of six Israeli companies handpicked by the US State Department and the White House to participate in the Global Entrepreneurship Summit in California.
And then, in October 2017, SolCold was a finalist in the deep tech competition at the Hello Tomorrow Summit in Paris.
Addressing the summit to an excited audience, Shenhav began:
“Yes, we are in Paris, the City of Lights, and above all these lights that we admire, there is the greatest, strongest light – the SUN. And while the sun is our greatest source of light, it is also our greatest source of heat on this planet. And whether here in Paris or in Tel Aviv, my home town, or LA, Beijing and practically everywhere on this planet, when the sun shines it emits radiation, which is absorbed by everything around us from buildings to cars, and in return it creates heat. So, this is the equation we know today – the stronger the sun, the hotter it gets. But we at SolCold have an alternative equation. We have a material that actually harnesses the suns energy into active cooling; meaning for us the equation is: the stronger the sun, the cooler it actually gets.”
Sunny Side Up
Potential imitators do not concern SolCold’s super cool team because the technology is so complicated. “We gathered a unique combination of knowledge in the worlds of thermodynamics, nanotechnology and quantum physics,” says cofounder Gadi Grottas, “and have been working on it for the past four years. We have also registered a PCT patent, which is pending before being published.”
Grottas expects the product to be affordable and to offer a quick return on investment.
He reveals that the materials used in the coating:
– all exist in the market
– are 100% “green”
– free of carbon emissions
– are activated by free energy from the sun.
When tested in a lab using a sun simulator, SolCold’s double-layered coating cooled an object by 1.2 degrees Celsius (2.2 degrees Fahrenheit) using the equivalent of only 1% of the sun’s energy.
“The paint could decrease electricity consumption by up to 60% and is expected to last for 10 to 15 years before needing a new coat,” says Grottas.
This is no “sugar coating” it – this coating is for real and is transformative.
In hot weather, electricity grids become strained as people use their air conditioning day and night. In Israel, the national electric company frequently issue warnings during summer — when temperatures soar over 40 degrees Celsius (104 Fahrenheit) — to use air-conditioners more sparingly, lest the grids shut down. Inevitably, electricity bills skyrocket.
The idea came to Shenhav sitting in his Tel Aviv apartment one sweltering summer over fours ago. “My air-conditioner was barely functioning – it was struggling to cope and came up with an idea which initially involved optic cables.” This he later abandoned in favour of harnessing the sun’s radiation for cooling.
“Now imagine what would happen for example,” says Shenhav, “if all the buildings in Tel Aviv have this coating on the roof. The entire city would consume 60 percent less energy in the hottest days of summer, and when that happens, our power plants would need to produce 60 percent less electricity – meaning much less CO2 (carbon dioxide) would be released into the air by the power plants.”
This is an enormous environmental benefit, asserts Shenhav.
The big question then is what happens in winter with less sun? While “the cooling effect would be reduced by 50% due to more rainy days when clouds hide the sun,” cooling will nevertheless still occur. At present, SolCold is targeting warmer climates such as the sun belt in the US, Central and South America, southern Europe, the Middle East, parts of China, Oceania and Africa.
Playing It Cool
Grottas has visited South Africa as part of promotion where there was interest among egg farms “because hot weather stresses laying hens and greatly reduces their productivity.”
It would also be extremely beneficial in rural South Africa for schools and hospitals.
Vision for Africa. This could be a game-changer in rural South Africa.
But Shenhav envisions entire cities in hot climates using SolCold to coat residential and commercial buildings, which would consume less energy and therefore reduce greenhouse gas emissions into the atmosphere.
“Our technology can cool anything under the sun,” he says.
With the material able to be applied to most surfaces, SolCold’s potential is infinite.
The Herzliya-based startup is currently raising funds and has begun trials. Commercial and residential buildings in Israel and Cyprus are waiting to get the trial SolCold treatment.
Meanwhile, says Grottas, the company has received hundreds of inquiries regarding orders and distribution rights — which he estimates to be worth around $100 million — from places including Africa, Australia, Brazil, Bolivia, Chile, China, France, India, Italy, Japan, Kuwait, Mexico, Philippines, Turkey and the United States.
Out Of This World
SolCold also has its sights on cargo, automotive, space and military markets, estimated at a total of almost $100 billion.
“Satellite and space applications especially could prove a huge market for us,” says Shenhav.
“In space, there is the problem to cool down equipment where there is no air to conduct heat and so expensive internal systems are used to isolate and ventilate,” he explains.
Therefore, “opportunities arise in space for our cooling coating that emits the heat via radiation.”
The same cooling principle may have huge potential for the military, in its application on specific hardware. There may also be an added advantage that the paint could in theory “also serve as a camouflage against infrared detection.”
No ‘camouflage’ can hide the sheer genius of Israel’s coolest new invention. Wherever its hot in the world, leave it to the Israelis to cool things down!