Sichuan DKT Energy Technology Co., Ltd.( A subsidiary of Hydrexia (China))

　　Recently, at the American Chemical Society’s National Meeting, chemist Ferland from the University of Campinas in Brazil introduced the concept of “humidity electricity.” This refers to the phenomenon whereby objects become electrically charged when exposed to humid air, offering a new approach to harnessing energy from the atmosphere.

　　It is well known that the atmosphere holds enormous potential for energy development, and there are numerous ways to harness it. Significant progress has already been made in generating electricity by exploiting air movement (wind energy) and by capturing the high-speed photons in sunlight (solar energy). However, at present, directly harvesting electrical charges from the air to meet humanity’s demand for power still seems rather far-fetched.

　　When people think of electricity in the air, lightning is usually the first thing that comes to mind. But why does lightning strike amid the billowing dark clouds in the sky? As early as the 18th century, Benjamin Franklin demonstrated that the sudden discharge of a large amount of electric charge is what gives rise to lightning. Yet how is such an enormous quantity of electricity generated in the first place? After all, millions of lightning strikes occur around the globe every year. The frequent appearance of such vast amounts of electrical energy in the atmosphere has naturally inspired energy researchers to dream of harnessing it. Now, Ferland’s research team claims they have unraveled the mechanism behind the formation of atmospheric electric currents, a breakthrough that may pave the way for directly tapping into the electricity present in the air.

　　The origins of lightning have long been the subject of considerable debate. Some theories suggest that lightning arises from collisions between ice and snow particles within convective clouds, while others propose that solar rain—streams of charged particles—delivers lightning to Earth. However, the explanation uncovered by Ferland and his colleagues differs from these accounts. They contend that lightning is generated when water vapor in the atmosphere becomes electrically charged. For a long time, scientists have assumed that tiny water droplets suspended in the atmosphere remain electrically neutral, even after they coalesce with small particles such as dust. Electrical neutrality refers to a state of equilibrium in solutions like water, in which molecules carrying opposite charges are balanced. Yet Ferland’s findings demonstrate that this assumption is incorrect: atmospheric water droplets do, in fact, carry minute electric charges. In experiments using commonly occurring aluminum phosphate and silica in the atmosphere, they observed that silica particles acquire a negative charge upon association with water droplets, whereas aluminum phosphate particles acquire a positive charge. In humid air, these charged particles gradually aggregate and eventually undergo large-scale discharge events. This explanation involving charged water droplets represents a fundamental challenge to the decades-old scientific consensus that water droplets are electrically neutral.

　　Researchers point out that electrification in humid environments is a common property of many metals. “My colleagues and I have found that ordinary metals such as aluminum and stainless steel naturally become charged when exposed to air that is electrically isolated yet highly humid. I believe this also explains the phenomenon of insulators becoming charged in humid conditions. From this, it is clear that air can be regarded as a vast ‘reservoir’ for storing electric charge,” said Ferland.

　　Having gained a solid understanding of atmospheric electricity, researchers set out to develop a device capable of harvesting electrical charges from humid air. The device is essentially a metal plate, similar in design to a lightning rod. One electrode of the plate is connected to a capacitor, which serves to separate and store the charges present in the air, while the other electrode of the capacitor is grounded. When the metal plate is placed in a high-humidity environment, it can begin to collect electrical charges. “If this experiment proceeds smoothly, it will mark the beginning of our ability to effectively control thunderstorms,” said Ferland. “This device is particularly well suited for tropical and subtropical regions with high atmospheric humidity.”

　　With every new concept comes a chorus of dissent. William, an atmospheric physicist at Oklahoma State University in the United States, put it bluntly: “Humidity-based electricity is simply nonsense. To charge water droplets with electricity the way lightning does, you absolutely need the collision of graupel and ice particles within convective clouds—there’s no getting around that.” And similar attempts to harness the electrical energy of lightning have all ended in failure. Recently, Alternative Energy Inc. in the United States erected a lightning-capture tower on the outskirts of Houston, but it has never been put to any practical use. “This theory has been refuted time and again,” said William, the company’s manager, with evident disappointment.

　　Humanity’s quest to tame lightning began as early as the temple of Zeus, the chief of the Twelve Olympian Gods. Though today taming lightning remains an elusive dream, it is possible that one day humans will indeed learn to harness its power and put it to use.