Sunday, March 29, 2020

How Zero Mass is using solar panels to pull drinkable water directly from the air


theverge.com
Lauren Goode@LaurenGoode

At some point while standing on the roof of an old car dealership in Scottsdale, Arizona, I noted that it was hot outside. Almost as if on cue, our cameras began to overheat and shut down.
The founder of Zero Mass Water told me that this kind of early November heat was actually mild for the Arizona desert – and that regardless of the dry climate, he and his team were still able to produce water.
Because that’s what Zero Mass does: harvest drinking water out of thin air, using a combination of materials science, solar power, and predictive data. The goal is to use this technology to go from a position of “water scarcity to water abundance,” said founder and chief executive Cody Friesen, regardless of whether you’re in an area where access to clean water is a serious problem, or living in a place where bottled water is often half-drunk and discarded.
Zero Mass’ water-harvesting technology has been in the works for the past six years. It was first developed at Arizona State University, where Friesen was teaching engineering and materials science. Over the past couple years, Zero Mass’ panels — called Source — have been available to specific customers: multi-lateral institutions, recipients of emergency aid, investors, and friends of the company.
But just a couple weeks ago, Source became more widely available to consumers in the US. So for the most recent episode of Next Level Season 2, we headed to Arizona to check out the Source panels and taste the water ourselves.
Photo by Vjeran Pavic / The Verge
At the highest level, Zero Mass “take[s] sunlight and air and we produce water,” Friesen said, as he showed me the Source panels. “As you drill into that, the air part of that equation is applying air into the materials that like water. So in the same way that when you leave the lid off a sugar bowl the sugar bowl gets a little clumpy, that’s because that sugar likes the water in the air. Our materials do exactly that.”
If you’re not following, that’s okay; you’d likely have to be an expert in materials science and fluid dynamics (or both) to grasp the process immediately. It’s a multi-step system. The middle strip of a Source panel is what you’d call a standard solar panel. On either side is a proprietary porous material that generates heat. Another proprietary material inside the panel absorbs the moisture from the air.
Then the panel uses sunlight to take the water back out of those materials and produce a process that’s not unlike water forming on grass; basically, when warm air hits a surface colder than itself.
At that point the condensed water ends up in a 30-liter reservoir under the panel. “The water is then flowed through a mineral block that adds calcium and magnesium, and brings the PH up so it’s slightly alkaline,” Friesen said, adding that the final product has what he calls “perfect mouthfeel.” Each panel costs $2000 and produces an average of two to five liters of water per day, Friesen said. A two-panel array costs $4500: $2000 per panel, plus a $500 installation fee.
When I asked Friesen who Source is for – whether it’s for consumers who can afford to pay $4500 out of pocket for cleaner drinking water at home, or for people who are suffering from a serious scarcity of clean water in less developed areas – his answer was broad: everyone.
“Everybody who drinks water has to make sure that water is healthful and available, right? That’s you and that’s everyone else on the planet,” he said. “So when we think about who the end customer is it really is anybody who thinks about making their water healthful and great.” Friesen added that Source panels have, so far, been installed in wide range of places: in hurricane-stricken Puerto Rico, at schools and orphanages for refugees in Lebanon, and at high-end homes in California.
Photo by Vjeran Pavic / The Verge
While visiting Zero Mass’ headquarters, I was able to taste the water that came from the panels on the roof of the building. It was good – much better-tasting than the tap water I had the night before.
But I didn’t have a lot of visibility into how the water from the standalone Source panels moved from roof to spigot, or how an average consumer would make that work in their own home. I asked to speak to early Source users to get a sense of how much water their panels were producing for them, and the company wasn’t able to make these early users available to me. We did visit the home of one Source user who lives not far from Zero Mass’ headquarters, and chatted with him outside of his home about his experience with Source; but found out that he, like many other early testers, was considered a friend of the company.
One element we did have visibility into was Zero Mass’ network operations center, a small room lined with computer monitors. The “NOC” is where engineers spend their days keeping a close eye on the performance of the panels distributed around the world, as well as changes in weather patterns that could impact water production. Each of the panels is connected, sending data not only to home base but also to the other panels in an array.
“Each panel has a programmable circuit board that runs an algorithm,” said Mike Robinson, a mechanical engineer at Zero Mass. “And the algorithm is constantly adjusting those set points so that we maximize the amount of water we make. We record that data….so we can teach the panel how to adjust to climate change such that it is always optimizing the water that it makes.”
Photo by Vjeran Pavic / The Verge
Zero Mass’ approach to harvesting water appears to be a technically sound process. And, as Friesen pointed out, Source’s total structural independence may be one of its most innovative features. But the company’s goal of making Source available to everyone, everywhere, is an ambitious one.
There are also questions worth asking around how cost-effective it is in the long run. Dr. Ashok Gadgil, Chair Professor of Safe Water and Sanitation in the Environmental Engineering department at UC Berkeley, has been working on water problems since 1993, focusing largely on developing countries. He said that harvesting water from the air is certainly a viable option – in fact, his Berkeley colleagues have been working on a metal-organic framework that also absorbs water from the air. But this wouldn’t be Dr. Gadgil’s first choice for sustainable water production.
“Condensing water from moisture in the air, is viable if I was on a desert island, I had lots of money and there was no other source of fresh water and I was going to die,” he said. “Then the value of my life is what is now pitted against the cost of that water.”
He emphasized that you have to “define the competition” when considering water options. “If am able to go to the supermarket and buy a bottle of water that’s the other alternative, the third alternative may be, I can just find some poor quality water and boil it and make it safe to drink. What is the comparison? Unless we define the competition, we wouldn’t know if this is the right affordability for the water.”
But Friesen insists that Zero Mass has the most sustainable water supply. “Today it takes far less energy (effectively none, since it’s entirely solar powered) to create drinking water with Source than any other mechanism,” he said via an emailed statement after we had left Arizona. He also said the company has long-term plans to provide Source water for advanced agriculture.
As the technology scales, he said, “that means water abundance in bulk.”