Covering clean energy, you notice that every few months, it seems, another company announces that it’s designed the largest wind turbine in existence. Most recently, the Energy Technologies Institute threw in its bid. The public-private partnership, based in Britain, doesn’t have anything to show quite yet, but it did invest almost the equivalent of $25 million U.S. dollars into creating the largest wind turbine blades anyone has ever seen.
How long will manufacturers be able to come out, month after month, with bigger, taller turbines—turbines that brush the clouds with their tips, even?
The blades that ETI is imagining will measure between 80 and 100 meters long—that’s about 87 to 109 yards long, which means each blade could be longer than a football field. It’s at least five meters longer than the longest wind turbine blades currently being used. It’s an almost unfathomably large piece of machinery: Imagine standing on one end of the gleaming blade and watching it stretch off into the distance...
There are a few reasons why bigger wind turbines are better. First, the amount of energy that a turbine produces is proportional to the square feet of its wingspan. Make a wind turbine a little bit bigger, and it produces a lot more energy. Bigger wind turbines are often also taller turbines, and winds higher up in the atmosphere blow stronger, yielding more energy. These first two math problems help explain why, as materials have gotten lighter and technology cheaper, clean energy companies have been building bigger turbine blades and taller turbine towers on which to perch them. But it turns out that bigger wind turbines are even more climate-friendly than smaller ones: a group of researchers reported last year in Environmental Science & Technology that “the bigger the wind turbine is, the greener the produced electricity is.”
The logic of proportions comes into play here, too: it doesn’t take that much more energy to produce a bigger turbine, but the amount that comes out is substantially larger.
Where does this logic end? How long will manufacturers be able to come out, month after month, with bigger, taller turbines—turbines that brush the clouds with their tips, even? The turbines being built now are dramatically bigger than any experts imagined possible ten or 20 years ago.
Eventually, though, the logic of proportions will limit the turbine’s growth. Right now, according to National Geographic, bigger turbines stop making sense when they become too heavy. “The weight goes up cubed, but the energy capture only goes up squared,” a turbine engineer told the magazine. Eventually, building those heavy turbines costs more than the additional energy generated can be sold for.
But that’s just for now. Different materials could come along, or different designs. Already, the turbines that the most advanced companies are building can reach up into the sky, where faster winds are blowing, and capture the energy up there. Really, the only reasonable limit to how big wind turbines will be and how tall they’ll grow is how tall we want them to be—how tall we’ll let them be.