Earlier this summer, we North Carolinians were surprised to learn that construction was set to begin on the first large-scale wind farm in our state and, in fact, the first large-scale wind farm in the entire region.

Chances are, it won't be the last.

Taller turbines mean better economics

What's making this 200-plus megawatt (MW) project near Elizabeth City viable, besides a hefty power purchase agreement from web-giant Amazon, is that wind turbines are getting taller and cheaper, and they're able to produce energy more efficiently, more of the time, in more places across the country. Here's how Craig Poff, one of the developers of the Elizabeth City wind farm, described the shift in the technology to the Associated Press:

"In the past this site barely showed up on old (wind) maps. It was a little brown smudge. The larger-diameter rotors are really the game-changer here."

More improvements on the horizon

What's really interesting here is that the Elizabeth City project is barely scratching the surface of what will become possible in the near future. While the developers are using taller towers (93 meters, compared to the standard 80-meter towers used until recently) it won't be long before we could see towers reaching up to 140 meters or more, according to several experts.

But why does this matter? Basically, the higher you go, the stronger and more consistent wind speeds will be.

Better design

But turbines aren't just getting bigger; they're getting more efficient too. Siemens, one of the world's leading turbine manufacturers, just revealed a hulking 7MW offshore wind turbine with a 154-meter rotor diameter that, thanks to more powerful magnets in the rotor, can produce 10 percent higher energy yield than previous versions of the same sized turbine. And, because the turbine is essentially gearless, Siemens is also claiming significant savings in terms of maintenance and other operating costs — factors that should lead to a stronger bottom line for wind farm operators.

Critics of wind power and renewables in general have long argued that intermittency — meaning the fact that the wind doesn't always blow and the sun doesn't always shine — prevents renewables from ever becoming more than a fraction of our overall supply. What's becoming increasingly evident, however, is that the cost of wind power isn't just coming down. It's ability to produce power is consistently going up too.

A more reliable source of power

In fact, new data from the National Renewable Energy Laboratory (NREL) suggests that wind power's capacity factor (a measure of how much energy a turbine produces over a year, compared to its theoretical maximum output) can already reach 55 percent with current, 110 meter towers, and could exceed 65 percent with near future technologies and 140-meter turbine towers. For comparison, wind's current average capacity factor languishes somewhere around 33 percent, and according to an article over at Cleantechnica, the average capacity factor for coal is 61 percent, and natural gas is 48 percent — leading some to speculate that wind could replace coal as our primary source of energy.

Here's a picture of what this type of change might look like for the Southeast, courtesy of a 2014 pamphlet from the Southeast Wind Coalition. (Remember, right now the region has exactly zero large-scale wind farms!)

wind power fact sheet.Southeast wind coalition fact sheet shows projected spread of turbines as technology improves. (Photo: Southeast Wind Coalition)Oh, and did I mention price?

The newly released 2014 Wind Technologies Market Report from the Department of Energy suggests the cost of wind power is at a record low. Given that President Obama's recently unveiled Clean Power Plan gave a stronger-than-expected push for renewables and wind, and that increased deployment and geographical spread should lead to significant economies of scale, we can expect to see these costs continue to fall. Because it will become increasingly feasible to site turbines near major population centers too, related costs like building transmission lines should come down as well. And then there are other innovations like modular turbines and lighter turbines (meaning lower transportation and manufacturing costs) and the increased availability of cost effective energy storage on the horizon.

Things really do look bright for wind energy right now.

Better wind turbines could spell trouble for coal
From taller towers to turbines that operate at lower wind speeds, wind energy just keeps on getting better.