Can a wind turbine produce water out of thin air? Prime Minister Narendra Modi reckoned it is possible and requested Henrik Andersen, the CEO of Vesta Wind Systems, a Danish maker of wind turbines, if his organisation could develop the technology.
Mr. Modi’s reasoning was that the spinning turbine would be able to “suck out moisture” from the air and condense it into water. He further theorised that a turbine could go on to “separate” oxygen from the air, and thereby could produce oxygen, power and clean water.
Mr. Andersen said that Mr. Modi’s ideas conveyed “passion” that would keep his engineers “very busy”.
The remark was picked up by former Congress president Rahul Gandhi as an example of how none among the PM’s advisers were bold enough to point out how mistaken he was.
Experts that The Hindu reached out to said that moisture in turbines worked to the detriment of blades, and there were simpler alternatives to extracting water than from running a turbine.
A turbine converts wind energy into electricity and its blades are designed to actively keep moisture out. There have been attempts to harness wind energy for making potable water but this involves using electricity as a power source to purify saline water.
“Condensation is the enemy of the turbine,” said Amit Rambhia, managing director, Panache DigiLife Limited, a firm that works on technology applications. “A wind turbine at a coastal village, for instance, would benefit if there was a well to draw water from the ground, and have a turbine power a system to pump out or distil the water into fresh water.”
In response to Mr. Gandhi’s comment, Railway Minister Piyush Goyal and the head of the Bharatiya Janata Party’s IT cell Amit Malviya tweeted out articles to defend the PM’s conjecture and impugn Mr. Gandhi.
One pointed to a 2012 article in CNN that described a French company, Eole Water, which claimed to have modified a wind turbine to manufacture drinking water from air. The company, according to the article, displayed a working prototype of the 24-metre tall modified turbine in the desert near Abu Dhabi that has been able to produce 62 litres of water an hour. Company officials then said that it would cost $600,000-$790,000 to install a single such turbine. A check on the company’s website revealed that the company has exited the turbine business. It said: “Eole Water was a water technology company that pioneered the use of wind turbines to produce drinking water. The brand is no longer operational however their legacy lives on through improvements in water technology.”
An expert from a wind turbine manufacturing facility in Chennai told The Hindu on condition of anonymity that the PM’s suggestion is “implausible”. A turbine could be connected to a solar still — an old contraption used to distil water — to make it more efficient at distillation. The expert added, “Too much moisture would be corrosive, too little would make it inefficient for the purpose of trapping condensate. However, far more energy would be expended in extracting too little water. It’s a technology demonstrator but not something that can be realistically implemented anywhere.”