Although we usually experience thunderstorms as a single experience— lighting bolts, lightning flashes, and thunder are not the same. The sky lights up and, in a matter of seconds, nature unleashes an enormous force in a natural atmospheric phenomenon. Understanding the connection between these three elements and, above all, their differences open the door to one of the biggest questions in modern engineering: Is it possible to harness and store the energy of a lightning bolt as a renewable source? And above all, why can't we do it yet?
To understand the energy potential of a storm, its components must be separated. Although they practically occur at the same time, a bolt and a flash of lightning, for example, are distinct expressions of the same electrical event occurring in the clouds, about two or three kilometers above the ground. And although we tend to use them interchangeably in everyday use, they are not the same.
A lightning bolt is an electrical discharge. It is the actual flow of electrons traveling through the air, triggered when the atmospheric insulation breaks down. According to the definition provided by the World Meteorological Organization (WMO), lightning bolts are the "chain reaction initiated by the acceleration of free electrons in the atmosphere, which causes an electric current to flow through the air."
In other words, lightning bolts are the result of a complex process and arise from the electrification of clouds with positive and negative charges caused by the friction of ice particles, raindrops, and hailstones. When it strikes, it acts as a bridge connecting two clouds or a cloud to the ground, and there are different types depending on their point of origin and destination. It carries an electrical charge and has enormous potential: billions of joules and a voltage of 30,000 amperes for an average lightning strike.
Lightning flashes, on the other hand, are emissions of light traveling at the incredible speed of 300,000 km/h. It is the glow visible in the sky or the optical phenomenon we perceive from a lightning bolt, but without its physical substance. It is a channel of ionized air that glows with a magnetic intensity due to the extreme temperature of the discharge.
Finally, thunder is the sound of the storm traveling at 343 meters per second—its soundtrack and acoustic wave. As it passes, lightning heats the air to a temperature that scientists generally agree is around 30,000 degrees. This heating causes an explosive thermal expansion of the air, creating a sonic shock wave that is the thunderous roar we hear.
Capturing energy: the big challenge
If a lightning bolt is capable of carrying so much energy, the question is obvious: why not harness it as a renewable source? The answer lies in one of the challenges of modern engineering—a challenge further complicated by the very nature of storms: they are brief and unpredictable, even for the most advanced weather systems.
The second challenge concerns storage. Although researchers have studied how to redirect lightning using laser guidance systems, the major challenge lies in how to encapsulate it and design a battery capable of absorbing such a sudden surge of power using ultra-fast storage systems.
The third challenge is efficiency. A technical study by the University of Tampere (Finland, 2025) noted that current technology is still in too early a stage to be sufficiently effective, and encourages focusing efforts on designing low-power lasers that activate in milliseconds to guide the beam to the discharge point.
Along the same lines, Switzerland developed the Laser Lightning Rod (LLR), led by Professor Farhad Rachidi of EPFL as part of a scientific consortium involving the University of Geneva (UNIGE), the École Polytechnique de Paris, and EPFL. Recently, they achieved a historic milestone: guiding multiple lightning bolts with high-power lasers at the summit of Mount Säntis. "It's not about 'capturing' the energy, but about demonstrating that we can influence the path of a lightning bolt in a controlled manner—an essential first step for any future attempt at energy harvesting," explained the director of the LLR.
The conclusions, published in the journal Nature Photonics, state that the current goal is optimized protection of critical infrastructure (such as airports and power plants) by increasing the coverage radius of traditional lightning rods.
Finally, discoveries of new materials such as graphene—which can function as supercapacitors with unprecedented thermal and electrical conductivity—and advances in nanotechnology, combined with the disruptive impact of AI, are paving the way for new materials capable of withstanding lightning strikes and the voltage spikes they generate without melting, and are opening the door to "harvesting" that energy.
Although current technology can already redirect lightning to protect infrastructure, the ability to harness the energy of lightning as an electrical current is not yet within the reach of today's technology. However, advances in laser physics and new materials suggest that, in the not-too-distant future, the sky could become another source of renewable energy.
