Durability is going to be key, though, if floating turbines are to survive in the squally waters currently earmarked for them. “These are incredibly hostile places,” says McDonald. “You are trying to engineer against the forces of God, almost.”
Thanks to this, it likely won’t be possible to access floating turbines for maintenance works as frequently or as easily as with fixed-bottom machines. In some cases, companies will have to tow their turbines to a port in order to carry out repairs.
And then there’s the cabling. It will likely be longer, bigger, and go deeper than the cabling for existing offshore wind farms. The heavy duty lines will also have to be robust enough to require minimal maintenance over their lifetime. All of this is “really challenging,” says McDonald.
Assuming all the engineering hurdles can be overcome, there’s still the question of how these gigantic offshore facilities will affect wildlife and ocean ecosystems. One study, published in April, considered various possible risks to marine life from the floating wind farms of the near future. Among those risks were the potential for animals to become entangled in the cabling or for birds to die when they collide with fast-spinning rotors, already a known issue for some on- and offshore wind farms.
“While I think, yes, we should move quickly, we have to think carefully about how we do it,” says lead author Sara Maxwell at the University of Washington.
She and her coauthors estimate that entanglement with cables won’t be a major issue, largely due to the sheer diameter of the cables expected to connect these structures out at sea. But the authors rated the risk of collisions with vessels installing and servicing the wind farms as “high” and the risk of birds flying into turbines as “moderate.” On the flip side, erecting floating turbines should be much quieter than installing fixed-bottom offshore machines, and therefore perhaps less disturbing to marine mammals, since pile-driving for the foundations would no longer be required.
Ultimately, the technology is so new that no one can be sure of the effects it will have on wildlife, says Maxwell. But she recommends extensive monitoring of new floating wind farms to collect data on their ecological impacts.
There’s little doubt that thousands of floating turbines are on their way. The better-than-expected economics of renewable energy have more or less ensured that. But there are still plenty of “open questions” about exactly how floating wind farms will work and how we’ll run them, says McDonald. The race is on to answer those — and fast.
More Great WIRED Stories