Springview, Neb., originally saw two 750-kilowatt (kW) wind turbines go up west of town in 1998. That was Nebraska’s first “wind farm” (such as it was), a demonstration project intended to verify that the turbines functioned and that power could reliably be produced at distribution voltages in Nebraska. Four years ago, having served their purpose, those turbines were removed.
The two new turbines that went up this past summer are distinct from the old ones – and from the new ones generally used these days in wind power plants around the country (including in Nebraska). Instead of using gearboxes to dramatically ratchet up the speed of the wind-driven rotor, the rotor on direct-drive turbines connects directly to a low-speed generator that uses permanent superconducting magnet technology to generate power.
The two 1.5-megawatt direct-drive wind turbines now generating power outside Springview were manufactured by the German company Vensys, but turbine giant GE is exploring direct drive as well with a two-year, $3 million research grant from the U.S. Department of Energy. The thinking is that the direct-drive turbines obviate the need for expensive gearboxes that can be highly susceptible to wear, and could operate more efficiently.
The two direct-drive turbines in Nebraska were installed by Omaha-based Bluestem, which sells the power generated from them to the Nebraska Public Power District.