When Lightning Strikes The Clock Tower

Marty McFly and the Doc travel in time by using the energy of lightning in Back to the Future, but is it really possible to generate electricity from a lightning bolt?

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AsianScientist (Jun. 24, 2016) – With the inter-monsoon period upon us, Singapore has of late been treated to one spectacular thunderstorm after another. If you are a lightning chaser, this is good news—one local photographer’s dramatic composite image of lightning strikes over Singapore’s urban skyline ended up taking the Internet by storm, garnering him international media attention.

If you are a runner, however, you might find yourself, as I did the other day, making a frantic scramble for the nearest shelter. Not to be melodramatic, but as torrents of rain crashed down and lightning streaked across the sky, some long-dormant part of my brain began to play the theme music from Back to the Future.

In the first installment of that iconic time travel trilogy, Marty McFly is stuck thirty years in the past. In a hair-raising last-ditch effort, he and inventor Doc Brown use a lightning strike to jump-start their time machine, powering Marty’s return to the present (the present being 1985, but trust me, this movie is timelessly entertaining).

With an average of 168 thunderstorm days a year, Singapore has one of the highest rates of lightning activity on the planet. But the title of lightning capital of the world, according to a recent study based on 16 years’ worth of data from satellite-mounted lightning sensors, really belongs to Lake Maracaibo, Venezuela. There, thunderstorms hit an average of 297 days a year, and lightning activity tops 233 flashes per square kilometer per year. It doesn’t take a wild-haired, wild-eyed mad scientist to wonder: what if we had the technology to harvest all that energy?

How to be a lightning thief

As it turns out, using lightning as a power source is shockingly difficult, not to mention costly. To start with, most lightning strikes occur within a cloud or between clouds; short of building lightning-gathering airships (someone please build a lightning-gathering airship!), we can only hope to harvest the roughly 25 percent of strikes that occur cloud-to-ground.

To do that, we’d have to build very tall towers to essentially act as lightning rods—these would attract lightning strikes and direct their energy into a state-of-the-art storage facility. But unlike Doc and Marty, who knew the exact time and coordinates of their lightning strike, we would have no such time traveler’s advantage. To capture maximum energy, we’d have to build an entire grid of these towers covering a large area—no small feat given that lightning-prone areas are often located in mountainous or tropical terrain.

Then there’s the problem of storage. All the energy in a lightning strike—estimates range widely from a million to a billion joules—is concentrated within several milliseconds, a mere blink of an eye. To absorb and store this huge burst without blowing the facility to smithereens, we’d need super-heavy duty electrical circuits and capacitors. For the energy to then be usable, we’d have to convert it to alternating current and release it to the power grid in a controlled fashion.

Assuming we had the resources and technology to engineer all that, could we then proceed to corner the energy market and achieve world domination? Preferably in style, i.e., while cackling evilly and unleashing lightning bolts from the palms of our hands?

Well, probably not. Back-of-the-envelope calculations suggest that even if we somehow managed to capture all the lightning strikes that hit Earth for a year at 100 percent efficiency, this would meet the world’s energy needs for all of nine days. Would-be dictators might be better off investing in solar energy instead. NEXT PAGE >>>

Shuzhen received a PhD degree from the Johns Hopkins Bloomberg School of Public Health, USA, where she studied the immune response of mosquito vectors to dengue virus.

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