David Hertz is founder and president of the Studio of Environmental Architecture and a partner for Skysource. Hertz can be reached at [email protected].
undefinedIn October 2018, the Water Abundance XPrize grand prize was awarded to the Skysource/Skywater Alliance for its Wood-to-Energy Deployable Emergency Water (WEDEW) system, which draws water vapor from the atmosphere and condenses into freshwater—up to 2,000 liters per day—using a biomass gassifier to generate the requisite energy; the cost of this process is less than $0.02 per liter. Architect David Hertz is a partner for Skysource, and he recently spoke with WQP Associate Editor Michael Meyer about the technology’s ability to help fight water scarcity.
Michael Meyer: Please explain how this technology works.
David Hertz: WEDEW is an atmospheric water generator. It makes water from air, in very simple terms. It does so using basically a collision between heat and cold and condensing it, much like one would have in, say, a warm room with a cold glass of ice water—you’ve got a condensation that forms. In this case, it forms in the air, and we’re turning water vapor into liquid water by bringing warm air through a filter into a chamber, hitting a cold surface, and then it’s essentially raining inside a box.
Meyer: In which climates can this technology be used?
Hertz: You need some amount of available water in the air, so the hotter it is and the more humid it is, the better it is for making larger volumes of water. What we did with the XPrize is we fundamentally created our own augmented environment, which gives us much more flexibility in where these machines can be used. The minimum that an atmospheric water generator can use, generally, is around 50% relative humidity; below that, you’re just using a lot more energy to make little volumes of water.
Meyer: How widely is this type of technology being used?
Hertz: The industry is somewhat in its nascent state, even though it’s probably about a 10-year industry. It’s expected to grow rapidly—a lot of independent studies have looked at it being a $9-billion industry by 2025, as we face extreme water scarcity. We should be seeing a serious increase in the demand for water, and when you stop to consider that there’s more water in the atmosphere at any given time than all the rivers—about six times the amount of the rivers of the planet—there’s a lot of water to be harvested in areas that don’t have water in the ground or accessible to them.
Meyer: What are the organization’s plans for the future?
Hertz: Our idea is to incorporate Skysource technology to have a deployable system. Within two weeks of our testing in the XPrize, we containerized [the WEDEW] into a 20-ft shipping container, and we ended up powering a conference in Oakland called VERGE, about the intersection of technology and environment; we created a microgrid. Part of what we imagine doing is deploying these WEDEWs throughout the world, adding to climate resilience and then being deployable for disaster relief.
Meyer: How are you working toward achieving those goals?
Hertz: We’re looking at capital raised, we’re looking at taking the $1.5 million from our XPrize win and seeding the advanced productization through a product road map, and we’re looking at partnering with nonprofits and [non-governmental organizations]. It’s kind of a profit-for-purpose model that could mimic something like a TOMS one-for-one, where whatever liters we generate here, we end up providing much-needed water for others.
Meyer: You are based in Southern California. How has the water quality been affected by the recent wildfires?
Hertz: There’s a water requirement in Malibu, but worse is really there’s very little active, available electricity, because all the telephone poles and power poles were burned. We actually have set up a WEDEW in Malibu. We’re powering a small community that doesn’t have access to electricity while providing water, and we’re expanding that in the future to include even refrigeration and the possibility of air conditioning, which is a byproduct of this process.
There’s a property that we own that’s called Skysource Ranch, where we’re doing a lot of the research and development for the XPrize and integration with alternative energy techniques and sustainable farming practices, and our community of about five or six homes was spared. There is an electrical grid—it just burned on both ends, so it has to be powered by generation.
