Wind power generation in the U.S. has been trending favorably upwards for wind farm owners. Primary contributing factors include the cost of wind turbine installations dropping by over one-third since 2010 as the capacity of turbines increased. Add-in the average capacity of turbines installed is now 2.32MW, up more than 200% since the late 1990s. Finally, capacity factors are also rising with an average of 42% reported over the period of 2014 to 2016, a significant increase of 31.5% over the period of 2004 to 2011. American Wind Energy Association (AWEA) reported that in 2019, the industry ended the year with just under 106 GW of operating wind power capacity and nearly 60,000 wind turbines.
Repowering wind farms
Repowering existing wind turbines with taller towers and longer blades are perhaps the most notable current industry trend. A repowered wind farm not only extends the life of the facility but leverages rising capacity factors found with modern technology along with more efficient power generation. One midwestern energy company, for example, has announced plans to spend upwards of $1 billion to repower 700 existing wind turbines with the promise of 19 to 28% more generation, depending on the farm site. Projections indicate that investment in repowering of existing wind turbine sites has the potential to grow to $25 billion by 2030.
Download our white paper Increasing Wind Turbine Reliability Through Blade Pitch Control Upgrades to learn about alternative approaches to wind turbine repowering, as more efficient technologies raise wind turbine capacity and reliability.
An incremental approach
Operational constraints from demanding environments
The pitch control system operates in a very demanding environment and the proportional control valve, one per blade, is arguably the device exposed to the harshest operating environment. Failure of only one of the three valves will force the wind turbine out of service. Data from operators confirm this observation with many field reports of pitch control valve failure within weeks of its first operation, with an unexpectedly large number of failures occurring within six months of service. Upon failure, a maintenance technician must travel to the turbine site and replace the pitch control valve in the hub. Performing this service can take one or more days, depending on the site location, technician availability, and weather conditions. Often the cause of the failure has been traced to circuit board failure due to inadequate vibration protection or the circuit board enclosure design does not prevent dirt and moisture ingress. The cost of a replacement pitch control valve is secondary to the cost of maintenance replacement evolution and the loss of energy generation.Pitch control valves, therefore, must be designed with these specifications to operate 24/7 in an extremely rugged environment:
-
Able to withstand heavy vibration, shock, and rotational forces (up to 50G on three axes).
-
Valve electronics must be electrically isolated from the turbine nacelle.
-
Capable of withstanding extreme cold and heat ambient temperatures.
-
Complying with IP65 standards for protection against dirt and moisture, a major cause of valve failure.
Raise your wind turbine capacity cost-effectively with new technology
One pitch control valve that has proven itself in multiple wind turbine applications is Parker's D1FC and the D3FC direct operated proportional DC valve with position feedback. The control valves receive an input signal (either 4-20ma or +/-10VDC) from the main turbine controller based on its monitoring of the generator output. Valve flow and performance specifications have been matched to the system requirements of the turbine so as to be compatible with the existing control parameters and co-exist with valves on the other axis.
Download our white paper Increasing Wind Turbine Reliability Through Blade Pitch Control Upgrades for a closer look at these alternate approaches, as more efficient technologies raising wind turbine capacity and reliability.
Article contributed by Tom Ulery, business development manager, Energy Team Parker Hannifin, North America Wind industry. He has many years of experience in hydraulic valves, as the applications manager for Hydraulic Valve Division.
Related, helpful content for you:
Hydropower's Future Relies on Next Generation Water Power Technologies
Condition Monitoring Solutions for Power Generation Plants
Read This if Your Wind Turbines Are Overheating
New Hybrid Actuation System Ideal for Renewable Energy Applications
Though gas-powered, internal combustion engine driven vehicles have been the norm in the automotive industry for over 100 years, electrification is growing. The traditional engine design was efficient, reliable, and easy to use, but gasoline powered vehicles are loud, dirty, and harmful to the environment. Given these drawbacks, electric vehicles have started to gain market share in commercial and personal markets. Public transportation is moving toward electrification at a faster pace than other markets, spurred by the deployment of electric vehicles in China.
The eHPS is ideal for buses and large commercial vehicles that require large amounts of hydraulic power for steering assistance, but also necessitate the quiet operation of an electric system. In addition, the eHPS has IP67 protection, is tested to SAE J1455 vehicle standards, and designed to ISO 16750 standards, making it ideal for replacement applications. Electrification is the future of the automotive industry, and public transit is leading the charge. 
This article was contributed by CT Lefler, marketing product manager (e-business), Pump & Motor Division, Parker Hannifin Corporation.
Phil Meyer, operations manager of the Whitman County Public Works Department, in Washington State, is tireless in his search for the right tools to help his 42-person team maintain over 1,900 miles of roads and 360 bridges and large structures in Southeastern Washington. The department has a daunting workload and inclement weather that can border on the extreme, productivity, durability and versatility are critical requirements of the equipment used at Whitman County. Typical projects include ditching to maintain flow lines, culvert maintenance, placing rip-rap, brush removal, bridge demolition, gabion basket installation, sloping and more.
The seven PowerTilts and their PowerGrip have been important assets for the Whitman County Public Works department. With PowerTilt and PowerGrip, the department accomplishes most tasks 25 to 50 percent faster. The Whitman County Public Works department has even recommended PowerTilt and PowerGrip to other local agencies such as the Washington State Department of Transportation and the North Latah County Highway Department in Idaho.
PowerTilt uses Parker’s innovative sliding-spline operating technology to convert linear piston motion into powerful shaft rotation. Each actuator is composed of a housing and two moving parts — the central shaft and piston. As hydraulic pressure is applied, the piston is displaced axially, while the helical gearing on the piston outer diameter and housing’s ring gear cause the simultaneous rotation of the piston. PowerTilt's end caps, seals and bearings all work in tandem to keep debris and other contaminants out of the inner workings of the actuator.
Over a decade of research, innovation and engineering has gone into making the PowerTilt and PowerGrip attachments integral solutions for work site efficiency. PowerTilt’s robust design has allowed Whitman County Public Works to keep a PowerTilt on their machine 100 percent of the time, year-round. 
This article was contributed by Jessica Howisey, marketing communications manager and Daniel Morgado, applications engineer, Helac Business Unit, Cylinder Division.
Gold Cup Heavy-Duty Pumps and Motors have long been respected in the industry for technical excellence in hydrostatic transmission applications in marine, drilling and shredding applications, among others.
