As we experience yet another in a string of seasons marred by natural disasters such as fires and hurricanes, it’s becoming ever more clear that global warming is having a snowball effect. And as temperatures rise across the globe, air conditioning becomes more necessary - but current air conditioning technologies can only address the symptoms of a warming climate while contributing to the cause. We need new technologies that can keep us cool without adding more carbon to our atmosphere.

Thanks to the hard work of scientists and engineers those new technologies are beginning to emerge, adding to the suite of solutions that started with solar and renewable energy. One particularly exciting development is in the field of radiative cooling. Here, ancient knowledge and practices meet modern science to create an innovative solution that could expand the impact of the solar industry.

Principles of Radiative Cooling

“As demand for air conditioning grows, so too will its environmental impact,” notes the Washington Post, and “by 2050, when the demand for air conditioning is expected to triple, cooling could become one of the world’s top sources of planet-warming gases.” This is quite a dilemma, but one that could be solved through radiative cooling.

What is radiative cooling? Ancient societies across the equator tapped into a law of physics long ago to make ice by filling shallow ceramic vessels with water at night. What those societies realized was that all objects give off heat, and on a clear night that heat (as radiation) can rise into the sky and escape, creating coldness through the absence of heat. This is how ice was made even in areas where the temperature never dropped below freezing. The same law of physics offers hope for a cooler future today.

Radiative cooling works by allowing infrared radiation within a certain range of wavelengths to pass upwards through dry, clear air. This ancient practice is now being combined with modern nanotechnology to create reflective films that can “reject” large amounts of heat from the sun to keep buildings cool during the day.

SkyCool Systems Leads the Way

A company called SkyCool Systems is on the leading edge of this exciting new development, offering optic film panels that “are highly reflective to sunlight but also emit thermal radiation exceptionally well to the cold of space through our atmosphere.” These panels can reduce or eliminate the need for air conditioning systems and operate without electricity. They avoid the pitfalls of air conditioning technology, including the release of fluorocarbons and dependence on fossil fuels.

The basis for SkyCool’s innovative approach was developed by Aaswath Raman, a materials scientist at UCLA who developed the mirror-like film using sophisticated nanotechnology. “The film sends heat into space while absorbing almost no radiation, lowering the temperature of objects by more than 10 degrees, even in the midday sun,” the Post notes. When applied to the roof of a large building, it can significantly reduce heat absorption and the need for air conditioning. Additional uses include cooling shaded outdoor areas like bus stops or carports, improving the efficiency of outdoor batteries through passive cooling, and helping refrigerated trucks use less energy to stay cool.

Radiative Cooling Plus Solar

SkyCool panels add another tool to the arsenal of passive cooling techniques that use the laws of nature to reduce energy dependence, lower electricity costs, and create more sustainable buildings. When combined with solar panels, the film could allow residential or commercial buildings to both capture their own energy from the sun and avoid absorbing its heat, doubly reducing energy costs. It’s an exciting match that will further expand the solar industry’s impact in slowing the effects of climate change, reducing dependence on fossil fuels, and helping lower energy costs for consumers.

If you’re curious about passive solar cooling techniques, radiative cooling solutions, or solar technology, the experts at Solar Design Studio are here to help. Our Everything Solar strategy is designed to provide the full range of technologies that you need to meet your unique energy goals. Contact us today to learn more.