Heat waves are becoming more common in parts of the US, which means more people are running their air conditioners for longer periods of time. However, those air conditioners can exacerbate the problem by emitting greenhouse gases, which contribute significantly to climate change.
SkyCool Systems is attempting to break the cycle by developing technology that promises to provide buildings with an alternative method of cooling by emulating how the planet cools itself.
“Our planet naturally cools itself by sending heat out in the form of infrared light or radiation,” said Eli Goldstein, SkyCool’s cofounder and CEO, through a process known as radiative cooling.
“We’re using that effect to essentially radiate heat out and out during the day and at night, even under direct sunlight.”
This is accomplished, according to the five-year-old company, through nanotechnology-based rooftop panels. These panels are made up of an optical film that emits infrared light while also cooling itself. According to the company, they resemble solar panels but actually do the opposite, reflecting 97 percent of the sunlight that strikes them and cooling the surface below.
A network of pipes is embedded beneath the panels in SkyCool’s model. Water is pumped into these pipes, which is kept cool by the panels and then pumped into a refrigeration or air conditioning system. This procedure is intended to relieve stress on the cooling system. Furthermore, because the panels cool naturally and do not require external power to operate, the system as a whole uses less electricity.
Since last year, a Grocery Outlet store in Stockton, California, has been using SkyCool’s system and claims to have seen a significant reduction in its electrical bills.
“After we had our SkyCool system installed, our electricity company increased their rates on us,” Jesus Valenzuela, the store manager, told CNN Business. “We actually didn’t see our bill go up at all. In fact, we saw it go just a little bit down,” he added. Valenzuela estimates that the panels save his business $3,000 per month.
Radiative cooling has been studied for years by scientists, including Goldstein’s co-founder and UCLA professor Aaswath Raman, who is a pioneer in the field. In recent months, a number of solutions and models for harnessing the process have been proposed.
However, there are some obstacles, including a problem that the solar industry is familiar with: it doesn’t work as well without sunlight.
However, the relatively high cost of the technology may be the most significant impediment to its widespread adoption.
“Our technology works best in hot, dry climates where the sky is clear, so when you have clouds, that blocks that radiative cooling window,” Goldstein said. “In the same way that [carbon dioxide] blocks light and sort of has that heat trapping effect, water vapor also will block infrared light.”
In a paper published earlier this year in the journal Nature, researchers from China’s Fudan University wrote that most radiative cooling solutions “suffer from a high manufacturing cost and large-scale production limitations.”
Goldstein wouldn’t say how much SkyCool’s panels cost, but he did admit that they are currently “expensive” compared to solar panels.
“New technologies like radiative cooling are often more expensive,” he said. “People are very sensitive to first cost, and so that is another barrier to getting new things out there.”
He attributes much of this to low production volumes. Scaling up production could help bring costs down, according to Goldstein, especially in developing countries like Asia and Africa, where SkyCool hopes to expand in the future. For the time being, the company is concentrating on commercial applications of the technology, though it hopes to eventually begin installing panels on individual homes’ roofs. It has panels installed at a retail store and a data center in California, among other places.
“We’re just excited to be able to use this new technology for good,” Goldstein said.
