Have you ever heard of the aviation incident known as the “Gimli Glider”?
It is frequently mentioned as a well-known example of a man-made disaster caused by mixing up measurement units. Here’s what happened: In July 1983, Air Canada Flight 143 had a malfunctioning fuel gauge, but the airline decided to repair it after landing at its destination, Edmonton. However, the aircraft couldn’t make it even halfway because all the engines stopped.
So, did a broken fuel gauge kill the engines? Well, the cause wasn’t that simple. The maintenance crew and the captain mixed up kilograms (kg) and pounds (lb), which meant the plane had only about 45% of the fuel it needed. And to top it all off, the broken fuel gauge meant the captain couldn’t even tell how much fuel was left in the tanks.
Picture this: an aircraft cruising at 41,000 feet (roughly 12,500 meters) with both engines completely dead. It’s the kind of nightmare scenario you’d rather not think about. But luckily, the pilots had experience flying gliders, and they managed to bring the plane down safely at an ex Royal Canadian Air Force base in Gimli, Manitoba — the closest landing strip they could find.
There were no serious casualties, and the aircraft sustained only minor damage. It continued to operate after repairs until its retirement in 2008, but due to the unusual accident, the aircraft came to be called by the unwelcome nickname “Gimly Glider.”
Those who have lived in the United States or the United Kingdom for a long time are likely familiar with the pound (lb), the mass unit of the yard-pound system (US or Imperial system). The kilogram (kg), used in most countries including Korea, is the mass unit of the International System of Units (SI, or metric system); the conversion ratio between the two units is approximately 1 lb ≈ 0.45 kg. And just like that, the plane left the ground with barely half the fuel it actually needed.
Other Absurd Accidents Caused by Units
The Gimli Glider is hardly the only case. In 1999, NASA’s Mars Climate Orbiter was lost in the Martian atmosphere because one team used Imperial units while another used metric. A $125 million spacecraft, gone because of a unit mix-up.
If you’ve never really paid attention to units before, are you starting to see why they matter so much? And honestly, the confusion hasn’t gone away. It’s still happening all around us, right now.
Renewable Energy News Never Makes It Easy
Over the past few years, as renewable energy policies have ramped up, we’ve been hearing a lot more about power generation in the news. But even in those reports — and yes, even in official government announcements — the misuse of electricity-related units is shockingly common. The most frequent offender? Confusing **installed generation capacity (GW)** with **actual electricity generation (GWh)**. See the difference? One has an “h” at the end. The other doesn’t. That tiny letter changes everything.
In February 2021, the South Korean government announced plans for an offshore wind farm complex in Sinan-gun, South Jeolla Province. They said the planned 8.2 GW facility would be “equivalent to the electricity generation of six next-generation nuclear power plants.” Now that you know GW is capacity and GWh is actual output, doesn’t that claim feel a little off?
Let’s break it down one more time. GW (gigawatts) describes a generator’s output — the maximum power it can produce at any given moment. GWh (gigawatt-hours), on the other hand, measures the total electricity actually produced over a period of time.
So, 1 GWh is the total electricity generated by a 1 GW generator running at full capacity for one hour.
With that in mind, let’s revisit the government’s claim.
An 8.2 GW offshore wind farm running for one hour under perfect wind conditions (around 11 m/s) could, in theory, produce 8.2 GWh. But wind doesn’t blow at the perfect speed around the clock. In South Korea, the capacity factor for wind power tends to hover around 30%. In plain terms, that 8.2 GW wind farm would realistically produce about as much electricity as a conventional plant rated at roughly 2.5 GW.
Nuclear plants, by comparison, run at a capacity factor of about 85–90%. So here’s what a fair comparison looks like:
- One next-gen nuclear reactor (APR1400): ~1.4 GW output, ~85% capacity factor → effective output of ~1.19 GW
- 8.2 GW offshore wind farm: ~30% capacity factor → effective output of ~2.46 GW
When you lay it out like this, the wind farm plan covers the equivalent of roughly ‘two’ nuclear reactors, not six.
The Noodle Shop Business Strategy
I was eating noodles at a local shop one day when I noticed a massive stack of bowls behind the counter. The franchise headquarters had probably told the owner something like, “You want to sell more noodles? You’re going to need more bowls.” And staring at that tower of bowls, it hit me — there’s a strange parallel between those bowls and the way installed capacity and actual generation get mixed up in official announcements.
Think about it. When the government says, “We’re building an offshore wind farm equivalent to several nuclear reactors,” it’s a lot like a franchise headquarters pushing shop owners to buy more bowls. But having a mountain of bowls doesn’t mean you can serve that many customers. If you don’t have enough pots to cook the noodles, those bowls just sit there, empty. Generation output works the same way as the noodles that are cooked, plated, and served to the customer. Equipment that can’t be fully utilized under real-world conditions is just… unused equipment.
Saying an offshore wind farm is “equivalent to six nuclear reactors” is basically like announcing, “We’ve got 600 bowls ready to go, so everybody’s going to eat well tonight.”
The Problem of Too Many Empty Bowls
If unit mix-ups were just typos, that’d be one thing. But what happens when these misunderstandings start piling up in the real world? If you keep buying bowls you can’t fill, that’s wasted money and if it keeps happening, the franchisees are going to stop trusting headquarters sooner or later.
Renewable energy policy is no different.
- First, trust in renewable energy erodes. People were told to expect that clean, cheap renewable energy would bring down their electricity bills. But when years go by and they start asking, “Hold on, why are coal plants still running?”, the public will behind the energy transition starts to crumble. Overpromise enough times, and people stop believing any promise at all.
- Second, once bad information piles up past a certain point, even good information gets thrown out with it. It’s the classic “boy who cried wolf” problem. And we’re already seeing the consequences: plans for new nuclear power construction are being announced, justified by warnings of electricity shortages from AI data centers and semiconductor complexes. It’s worth asking whether renewable energy’s real potential is getting buried under the backlash from years of inflated numbers.
- Third, policy itself can get knocked off course. The Gimli Glider pilots pulled off their emergency landing because they were exceptionally skilled. But energy policy doesn’t come with an abandoned military runway you can glide into when things go south. When plans built on bad numbers run headfirst into reality, the fallout lands squarely on businesses and households.
So, What Do We Do?
After the Gimli Glider incident, the global aviation industry moved faster to standardize metric units and introduced double-check protocols for fuel calculations. One mistake drove an overhaul of the entire system.
What about our energy sector? When will the day come that a “small detail” like the difference between installed capacity and actual generation is properly understood in public debate?
Next time you see a headline that reads “Construction of a ○○ GW Renewable Energy Complex,” stop and ask yourself: is that actual generation, or just installed capacity?
If enough people start asking that one small question — if enough of us stop being fooled by the sleight of hand hiding in a single unit — policy will have no choice but to get sharper, clearer, and more honest.
You’re not just staring at a stack of empty bowls and dreaming of a feast… right?
