OFFERING MEMORANDUM Global Offering of up to ... - Nordex
OFFERING MEMORANDUM Global Offering of up to ... - Nordex
OFFERING MEMORANDUM Global Offering of up to ... - Nordex
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Glossary<br />
Alternative energy sources Those sources <strong>of</strong> energy which renew themselves constantly and<br />
are practically inexhaustible: solar energy, biomass, d wind<br />
energy, ambient heat, etc. Contrast with d conventional energy<br />
sources.<br />
Asynchronous genera<strong>to</strong>r The rotation speed <strong>of</strong> the ro<strong>to</strong>r <strong>of</strong> an asynchronous genera<strong>to</strong>r is<br />
different <strong>to</strong> the d grid frequency (50 Hz in Europe Hertz). Due <strong>to</strong><br />
its construction it is very robust and does not require much<br />
maintenance. The double-fed asynchronous genera<strong>to</strong>r has several<br />
technical advantages. Due <strong>to</strong> the additional costs the decision <strong>to</strong><br />
use a double-fed asynchronous genera<strong>to</strong>r is a balancing <strong>of</strong><br />
economic and technical considerations. Double-fed asynchrouous<br />
genera<strong>to</strong>rs have been used for several years in conventional power<br />
plants which means that it is possible <strong>to</strong> rely on operational knowhow.<br />
Average annual wind speed The average wind speed over a year, measured in d m/s.<br />
Blade pitch adjustment Turning the ro<strong>to</strong>r blades <strong>of</strong> a d pitch-regulated turbine around<br />
their longitudinal axis. In the case <strong>of</strong> a pitch-regulated wind<br />
turbine, the turbine’s electronic controls constantly measures the<br />
power output. When the power output is <strong>to</strong>o high, the controller<br />
sends a command <strong>to</strong> the blade pitch mechanism which<br />
immediately pitches (turns) the ro<strong>to</strong>r blades slightly out <strong>of</strong> the<br />
wind. Conversely, the blades are turned back in<strong>to</strong> the wind<br />
whenever the wind drops again. The ro<strong>to</strong>r blades thus have <strong>to</strong> be<br />
able <strong>to</strong> turn around their longitudinal axis (<strong>to</strong> pitch). During normal<br />
operation, the blades pitch a fraction <strong>of</strong> a degree at a time while<br />
the ro<strong>to</strong>r is continuing <strong>to</strong> turn.<br />
Designing a pitch-regulated wind turbine requires sophisticated<br />
engineering <strong>to</strong> make sure that the ro<strong>to</strong>r blades pitch exactly the<br />
amount required. On a pitch-regulated wind turbine, the<br />
electronics control will pitch the blades every time the wind<br />
speed changes, which ensures that the ro<strong>to</strong>r blades are always at<br />
the optimum angle in order <strong>to</strong> maximise output across all wind<br />
conditions.<br />
Certification Wind turbines are certified pursuant <strong>to</strong> certain regulations. This<br />
ensures the correct planning and safety <strong>of</strong> operation <strong>of</strong> the wind<br />
turbines. Germanische Lloyd (GL), based in Hamburg, is the<br />
authoritative body for wind turbine certification in Germany.<br />
Constant-speed wind turbine Turbine which can operate at only one or ^ in worst cases two fixed<br />
rotation speeds. While technically far simpler, these turbines do not<br />
permit optimal use <strong>of</strong> d wind energy (see d variable-speed wind<br />
turbine).<br />
Conventional energy sources All d fossil fuels as well as nuclear power and hydroelectric power.<br />
Cut-out speed The wind speed at which the d wind turbine is shut down for<br />
safety reasons (as a rule around 25 meters per second d m/s).<br />
G-1