GE's newest wind turbine, the numeric 2.5-120 (2.5 megawatts in output and 120 meters in rotor diameter) is so big that engineers had to compensate for the difference in wind speed between the top and bottom of the blade-top by allowing the pitch to change during rotation, and so tall that the 139 meter hub height is being advertised as "ideal for heavily forested regions," according to the GE press release. After all, the higher you build, the higher the wind speed. But now this big industrial giant also comes with a brain big enough that GE calls it "brilliant," because it's plugged into what CEO Jeff Immelt calls the Industrial Internet, an evolving global network that links sensor-rich machines, the people who oversee them, and powerful analytics, all working together to increase the new turbine's efficiency and power output 25 and 15 percent. "This is the first wind turbine that utilizes the Industrial Internet," Vic Abate, vp of GE's renewable energy business, confidently points out. He explains that a wind farm filled with 2.5-120 turbines will send about 150,000 data points every second to be analyzed in real time by automated algorithms at a remote operations center (ROC), where, Abate adds,"We are able to optimize power output and make it more predictable and reliable." That's exactly what utilities want, and it should guarantee a lot of extended service contracts for GE.
Coping with curtailment
So to understand the financial benefits of the Industrial Internet, you'll have to leave those spinning hulks behind, travel to upstate New York and visit one of GE's remote operations centers - a turbine's actual brain and fiber-optically wired cerebral cortex - to watch the staff of 30 technicians monitor 6,000 wind turbines around the globe and around the clock.
You'll find that much of the oversight that once required human intervention has been completely automated. And no where is this more important than in the nerve-racking exercise of curtailment. Usually, when there's plenty of demand, wind farms and turbines run full out, pedal to the metal. But during periods of grid congestion or late at night when demand drops even as the wind still blows, grid operators will signal wind farms to throttle back and curtail power. Such abrupt, downward supply shifts make running a wind farm difficult, especially when every turbine represents an independent engine that must be turned on or off quickly while wind and demand fluctuate unpredictably. Not surprisingly, too many turbines could be turned off, causing a wind farm to lose money; the continual start and stop also creates unwanted wear and tear, forcing operators to make extra repairs.
Using the Industrial Internet
Curtailment has grown worse, becoming much more common since 2008 as nationwide wind capacity increased from almost nothing 10 years ago to more than 60,000 megawatts and 45,100 turbines now. This can be particularly costly for wind projects, according to AolEnergy, since their capacity factors are low. Good projects generate just 30-40% of their rated capacity over a year, so being unable to sell output when winds are most productive can hit project revenue hard. The ROC software that will monitor 2.5-120 turbines around the country and automate curtailment is GE's new WindCONTROL. The GE engineers who developed WindCONTROL call it "cruise control for wind turbines." According to a GE press release, the software monitors power requests from the grid, and then automatically notifies the turbines, which use blade-pitching technology to reduce electrical output to the desired level, smoothly managing the change across a whole fleet of turbines, instead of turbine-by-turbine in clumsy increments of 1,600 kilowatts.
WindCONTROL keeps power output at an optimized peak, while keeping the whole farm spinning. "The simplest way to think of that is like anti-lock brakes," Abate explains. "They allow you to stop in controlled shorter distance. It's the same thing. By controlling how we slow these turbines in a controlled fashion, we minimize the loads, which enables us to get the bigger rotor." The system can also add power when it's needed. If one turbine "trips" and stops generating power, WindCONTROL will command the others to incrementally pitch in so that the total output remains constant, which is the sweet-spot grid operators want. GE's Minesh Shah, an engineering manager at GE who runs the team working on this "brilliant" wind turbine, discusses how WindCONTROL works in the video above. An onsite storage system, GE's sodium Durathon battery, originally designed for cell phone towers, is another innovation that takes the pain out of intermittent wind, according to greentechmedia. The batteries can store excess power and release it when wind slows down. "It's predictable power," Abate says. "With just a small amount of storage, I can integrate hundreds of megawatts of wind power into the grid seamlessly." GE has already successfully demonstrated the integration of wind power and batteries at its facility in California. The company will build the first prototype of the 2.5-120 turbine in the Netherlands next month.
Measuring temperature, wind speeds and location
First Wind, a Boston-based independent wind company that owns and operates 264 turbines at eight sites across the U.S., will install WindCONTROL on 95 GE wind turbines at two Maine wind farms. "The effect of the curtailment on wind turbines has been an area of concern for us," says E.J. Martin, VP of operations at First Wind. GE is already servicing First Wind's fleet of GE turbines to target problems faster, diagnose issues fully before a technician arrives, and isolate maintenance with fewer disruptions to the overall wind farm. Sensors are measuring temperature, wind speeds, location and pitch of the blades, and sending the data to GE software for analysis to improve performance. Upgrades on 123 turbines on two wind farms have delivered a 3 percent increase in energy output, or $1.2 million in additional annual revenue..