Would That Blimp That Harvests Clouds for Energy and Water Actually Work?

We turned to the scientists to find out.

Oct 3 2014, 2:00pm

Images: Andrew Kazantsev/Cloud Power

A lot of big ideas are floating around right now, and Kickstarter backers and venture capitalists are eagerly sorting through the lot of them. One that recently drifted to the fore was a Russian designer's plan to harvest clouds for water—and energy.

The Cloud Power project ultimately ended up raising only $2,926 of its $14,052 IndieGoGo campaign fundraising goal. While this failure is likely a good barometer of people's interest in the project, it doesn't say anything about whether or not it would actually work. Naturally, we set out to find out.

Conceived by Russian inventor Andrew Kazantsev, Cloud Power is essentially an aerostat weather balloon called Air HES (Air Hydroelectric Station), which he and his team intend to launch 7,000 feet into the atmosphere. Equipped with a mesh fog collector inspired by MIT mechanical engineering professor Gareth McKinley's project, Cloud Power would use gravitational force to funnel water down through tubes to the ground, where it would simultaneously provide clean drinking water and generate hydro-electric power.

Kazantsev told me that with roughly average weather conditions, ten square meters of mesh could capture enough condensate to supply one human with 1,000 litres of fresh water and 180-200 watts of electricity (on average consumption) per day. He also claimed that with $5 million, AirHES—the name of his Cloud Power system—could supply water and electricity for a city of 100,000 people.

"The main aim is to demonstrate its workability to attract investors," said Kazantsev. "I am sure that this technology can easily win, becoming the basis for future energetics because it potentially provides a huge source of very cheap, green, and renewable power and fresh water for all people on Earth."

"AirHES is very simple technology," he added. "After proof of workability, this could be produced by any small firm anywhere across the globe (Africa, South America, Asia, and so on)."

Kazentsev's idea is theoretically possible (read his feasibility study here) and he hopes to create functioning prototypes within a year. But, how practical would it be? I put the question to some scientists and a green energy advocate.

Mark Z Jacobson, a professor of Civil and Environmental Engineering and the director of Atmosphere & Energy Program at Stanford University, took a brief look at Kazentsev's idea. What stood out for him is that the only way to prevent evaporation of water from the mesh (upwards of 75 percent, by his estimation) would be via enclosed tubes draining to the ground; an idea that Kazentsev incorporates into his design.

While this would seem to support Kazentsev's invention, Jacobson cautioned that "the entire scheme depends on cost relative to other options," which he said he couldn't evaluate. Since Cloud Power is such a novel idea, apart from the fog collection, getting these aerostats off the ground around the world would be a significant effort. Feasibility is one thing, but convincing governments and investors is quite another—they might opt for cheaper or less daring options.

Lynn Russell, Professor of Atmospheric Chemistry at the University of California-San Diego, said that there would also be limitations on both the amount of water that could be collected, and the power that could be derived from it.

"The inherent limitation to both is the collection rate, for which there is no data given except, 'We suppose that we have gotten approximately five liter/m2 per hour (by analyzing the aerostat positions),'" said Russell.

Russell noted that Kazantsev's figure is much lower than is needed for energy and water scale-up applications. She also had some problems with lack of published reports, and with Kazantsev's patent containing little data.

"The calculations seem to assume that all cloud water within the mesh is collected, which is not true for any existing cloud water collection devices," Russell explained. "There is also a large variability in cloud water content depending on location and season, so there should be some discussion of that when scaling up to 'plant' level."

Put more simply, not all geographical locations are ideal for aerial water collection. Washington and Oregon might be a good spot to float Cloud Power, but America's southwestern desert, say, is hardly rich in clouds.

Another potential hitch in Kazentsav's plan, which Russell said is being overlooked, is friction losses in the falling water, both in free air and in the tubes.

"Waterfalls have sufficient mass flow (per impinging area) to overcome this," she said. "But [five liters per hour] would not, so again it comes back to what collection rate can be achieved, and probably some picky details about the tube used for collection."

Let's assume, for a moment, that Kazentsev could overcome these obstacles. What would it look like? Would we expect to see a bunch of weather balloons suspended in the air all around us, with several tubes dropping like tentacles 7,000 feet (or less) to the ground? That vision seems a bit like Wellsian science fiction. And one can well imagine, homeowners would likely complain—Not-in-my-backyard, or NIMBYism, would be a problem. 

Stephen Lacey, Senior Editor at Greentech Media, said that since he hadn't spoken to any experts or engineers about the project, he couldn't comment on Cloud Power's technical aspects, but he felt there would be "permitting nightmares" for the technology.

"There are thousands of flights across the country each day—how would this interfere with FAA procedures?" he said. "It took many years for the FAA and military to finally say that wind turbines weren't dangerous to airplanes or radar systems. I can only imagine how ridiculously hard (and costly) this would be to get through the permitting process."

Lacey has seen hundreds of inventions like Cloud Power come and go over the years, so he's skeptical. 

While fog collection does have some legitimacy granted it by the MIT project, Kazentsev's idea is of a different type and magnitude. It's ambitious and visionary, though maybe more than a bit impractical. But, that doesn't mean it's not worth a shot. The worst that could happen is Kazentsev could be proven wrong.