The 1977 classic Star Wars: A New Hope gave fans their first look at this galaxy far, far away, and our introduction to one of the most iconic characters of all time, Mark Hamill's Luke Skywalker. While fans could easily relate to Luke's plight, wanting to leave his adopted family's farm to strike out on his own, we learned quickly that almost everything in this universe is different than our own, including the farm he lived on. Luke's uncle Owen Lars (Phil Brown) and aunt Beru Lars (Shelagh Fraser) ran a moisture farm on the desert planet of Tatooine, where they used devices called "vaporators" to draw moisture from the air to produce drinking water, and today we have word that this fictional technology may become a reality.
CNN has presented a report from Amin Al-Habaibeh, a Professor of Intelligent Engineering Systems at Nottingham Trent University, as part of an ongoing series known as The Conversation, which is a "collaboration between journalists and academics to provide news analysis and commentary." While the moisture farm on Tatooine was not a huge part of the story at large, the practice of moisture farming was considered an essential part of life on a desert planet like Tatooine. Amin Al-Habaibeh explained how, in theory, these devices called vaporators may have worked.
"If you sit in your garden on a hot, humid summer day with an iced glass of water, you will notice water droplets forming on the outside of the glass. The Star Wars vaporators on Tatooine may have worked using a similar principle. Cooling down warm air produces condensation, which can then be collected. Rain is actually a natural phenomenon of the same principle. When warm, humid air cools, it loses its capacity to maintain its water content and precipitation occurs in the form of raindrops."
While, in the first Star Wars movie, this technology was used on an arid desert planet, this real technology would work best in a more humid climate. In conditions with 100% humidity, the air at 40 degrees Celsius (104 degrees Fahrenheit) contains roughly 51 milliliters of water per cubic meter of air. When the temperature is dropped to 10 degrees Celsius (50 degrees Fahrenheit), there is only 9.3 milliliters of water per cubit meter of air. Amin Al-Habaibeh contends that if the air is cooled from 40 degrees Celsius to 10 degrees Celsius, they should be able to extract the difference, which would be 41.7 milliliters of water per cubic meter of air. With this new technology, Amin Al-Habaibeh states that they could produce 147 liters of water per hour, which could be done with a minimal amount of energy, roughly the same that it would be needed to power 18 domestic air kettles. Here's what Amin Al-Habaibeh had to say about why this technology won't work as well in a desert climate.
At lower humidity, such as in a desert, there is less water in the air and so the system will be less efficient. You have to cool more air to extract the same quantity of water and that requires more energy. This can make the current technology too expensive for countries where water shortages are most severe. What you need is a more efficient way of capturing water vapor. The simplest way of drawing water from air is with passive technology that provides a cool surface for fog or water vapor to condense onto. The selection of material and surface quality are critical for maximizing water collection. For example, farmers in Chile use a steel mesh to catch water from fog. Researchers have shown this can be made more efficient by adding a special coating that attracts water molecules."
Scientists at MIT have come up with another method that uses a "metal-organics framework" which is powered by sunlight, and would be much more effective in desert areas than the previous method. This method uses, "a network of metal and organic molecules that can easily trap water vapor, which is then released using heat captured from the sun." According to a new study, just one kilogram of this metal-organics material can harvest 2.8 liters of water a day, with relative humidity levels as low as 20%, with no external power source needed whatsoever. Amin Al-Habaibeh is also working on a water-from-air system that uses old fridges and freezers along with other recycled components such as old computer fans and cell phone chargers, which would be used to create a low-cost system for developing countries. While it remains to be seen when exactly this Star Wars technology may become a reality, it's clear there is plenty of work being done to bring Star Wars moisture farms to life.