Blowin' in the Wind
It was just like the Egyptian obelisk going up in "The 10 Commandments," only a lot faster, and the slaves were replaced by portable hydraulics. Oh, and there was a 32-ft diameter fan mounted on top.
This tower-raising took place at Wago Corp.'s (www.wago.us) U.S. headquarters in Germantown, Wis. where the company installed a 100-ft tall wind turbine The gleaming white tower was "tipped up" in less than 10 minutes by a portable hydraulic unit hooked up next to the tower. After that, it only took another 15 minutes to bolt down the tower, hook up its electronics and get it spinning in the breeze of Wisconsin's famous "dairy air."
Capable of generating 20 kilowatts (kW) for Wago's multi-function facility, the small-scale, commercial-grade VP-20 turbine was built by Renewegy (www.renewegy.com) in nearby Oshkosh, Wis. The turbine employs Wago's 787 Series power supplies, 756 Series cables/connectors, 288 Series fuse blocks and back-up capacitor module.
The wind turbine's initial cost was $80,000, but state and federal incentives allowed Wago to reduce its bill by about $35,000. Other VP-20s have been installed at SCA Tissue in Neenah, Wis., and at the North Texas Job Corp Center in McKinney, Texas. Renewagy reports that it can install single 20-kW units on farms, 40-kW dual-units to serve schools and 100-kW five-unit systems for small wind farms and commercial applications.
VP-20's three blades are usually situated at 10° pitch, but they can be turned to achieve as much as 110° pitch to better handle variable wind speeds and improve power output. Its variable-pitch (VP) capability is patterned after utility-scale turbines, and it controls pitch for each blade to within 0.1°, while pitching at speeds up to 15° per second. A closed-loop, active-pitch servo manages blade speeds in wind conditions ranging from 6.7 mph to 55.9 mph, while an active-yaw servo ensures optimum power generation by directing the blades into the wind.
At 100 rpm, the turbine begins to produce power, and at 110 rpm it generates its normal 20 kW. As a result, wind power from the turbine will meet approximately 10% of Wago's electrical needs at its engineering, manufacturing and sales hub. Also, by producing more of its electricity onsite and using less from the local grid, Wago will save half again as much electricity because its local utility won't have to generate, send and lose as much power by sending it long distance.
"Renewegy's inventive hydraulic tip-up function demonstrates Wisconsin ingenuity and manufacturing capabilities," says Tom Artmann, Wago's president. "We're proud that our products are supporting VP-20s nationwide and are looking forward to supplementing our manufacturing facility with renewable energy."
In addition, VP-20's dramatic tip-up capability is enabled by its unique, monopole tip-down tower, which enables Renewegy's portable hydraulic cylinder system to raise it at installation and then come back later and easily lower it for servicing. This tip-up method eliminates the high cost and time required by the large cranes and heavy-duty equipment used to install and help maintain larger wind turbine towers.
Also, because power supply and signal reliability are essential for coping with widely variable wind conditions, Renewegy specified Wago's IP67-grade 756 Series cables and connectors for VP-20's microprocessor-driven control system. Crucial for safety and reliability, these connections resist dust, water and mechanical loosening caused by vibrations.
Likewise, VP-20's control cabinet is supported by Wago's 288 Series capacitor back-up module and 787 Series Epsitron Pro 24 VDC power supplies. They were specified because they feature PowerBoost, which provides twice the current at constant voltage for approximately 4 seconds, which helps ensure reliable, cold-weather start-ups. VP-20's controls also include Rockwell Automation's (www.rockwellautomation.com) Allen-Bradley Soft Starter to help ramp current between the turbine and its induction generator, and E3 overload relays to measure voltage and current.
VP-20 uses CANbus for internal communications and then converts to Ethernet for longer-distance communications. For example, Renewegy can monitor the wind turbine and even remotely turn it on or off, if needed.
Besides the wind turbine, Wago reports it's already saved 10% to 20% on lighting by installing high-efficiency fluorescents from Orion Energy Systems (www.oesx.com) in Manitowoc, Wis. In addition, it's also using Circon Systems Corp.'s (www.circon.com) sensors, controllers and networking to automate its lighting, HVAC and fans, which has shaved its electric bill by another $1000 per month.