Sunday, March 11, 2018

These Huge New Wind Turbines Are a Marvel.  They’re Also the Future. - by David Roberts

The latest model has blades longer than football fields.

Wind turbine heights (Credit: Javier Zarracina) Click to Enlarge.
The declining price of solar power gets more press, but there are big things happening in wind technology too.  And I mean big.

The math on wind turbines is pretty simple:  Bigger is better.  Specifically, there are two ways to produce more power from the wind in a given area.

The first is with bigger rotors and blades to cover a wider area. That increases the capacity of the turbine, i.e., its total potential production.

The second is to get the blades up higher into the atmosphere, where the wind blows more steadily.  That increases the turbine’s “capacity factor,” i.e., the amount of power it actually produces relative to its total potential (or more colloquially: how often it runs).
Anyway, making turbines bigger and bigger is the name of the game.  When it comes to land-based (onshore) turbines, that process begins to run into various non-technical limitations — transportation and infrastructure chokepoints, land use concerns, worries about views, large birds, shadows, etc.

But especially in Europe, wind power is increasingly moving out to sea.  And out in the ocean, with land barely in sight, the only limitation on size is engineering.  Consequently, offshore turbines today are vaulting up even faster than onshore turbines have over the past decade.

A vivid example of this trend popped up on Monday, when GE Renewable Energy announced that it will be investing $400 million to develop a new monster turbine:  the Haliade-X, which will be (at least until the next big announcement) the biggest, tallest, and most powerful in the world.  The first units are expected to ship in 2021.

It will be impressive as an engineering feat, but the significance of growing turbine size goes well beyond that.  Bigger turbines harvest more energy, more steadily; the bigger they get, the less variable and more reliable they get, and the easier they are to integrate into the grid.  Wind is already outcompeting other sources on wholesale energy markets.  After a few more generations of growth, it won’t even be a contest anymore.
Bigger turbines that run more often are going to crush all competitors
Let’s consider what these rising capacity factors mean for wind.

I often return to this 2015 post by energy analyst Ramez Naam on the ultimate potential of wind power.  “Wind at 60% capacity factor,” he wrote, “even at the same price per kwh of today, would be tremendously more valuable than it is now, with fewer limits to how much of it we could use.

Why is that?  Several reasons.
  • The more variable a source is, the more backup is needed to firm it up and make it reliable.  (Today, backup is most often provided by natural gas plants, though batteries are creeping up.)  By making wind less variable and more reliable, higher capacity factors reduce backup costs.
  • Variable renewable energy (sun and wind) tends to “eat its own lunch.”  Because it all produces energy at the same time (when the sun is shining or wind is blowing), the next increment of capacity added has the effect of lowering the clearing price for all the other increments.  The more energy comes online at once, the lower the price.  By spreading its energy out over a longer period — roughly twice the 32 percent of 2011-vintage turbines — a turbine with 60 percent capacity factor blunts and slows this price-suppressing effect.
  • By extending its hours of operation, a high-capacity-factor turbine is more likely to be producing during demand peaks, when power is most valuable.
A capacity factor of 60+ percent isn’t quite “baseload,” but it sure looks a lot less variable.  So turbines like the Haliade-X would be more valuable even if the price of wind electricity stayed the same.

But of course it won’t stay the same; it has dropped 65 percent since 2009.  A recent NREL report projected that innovations in wind power technology (of which bigger turbines is one of many) could drive it down another 50 percent by 2030.  (Researchers at the University of Virginia are working on a design for an offshore turbine that will tower, no lie, 1,640 feet, higher than the empire state building.)

Say new US wind turbines reach an average hub height of 460 feet by 2025, roughly in line with current projections.  According to NREL data, such turbines could hit capacity factors of 60+ percent across more than 750,000 square miles of US territory, and 50+ percent across 1.16 million square miles.

That much wind, at that capacity factor, with foreseeable advancements in wind tech, will produce power cheap enough to absolutely crush all competitors.  And 2025 isn’t that far away.

Read more at These Huge New Wind Turbines Are a Marvel.  They’re Also the Future.

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