“ Studies with a particular
focus on real-life demands ”
energynautics provides studies on wind turbines especially taking into account the compliance with current real-life requirements and future developments that will go beyond these requirements. Our research and consulting activities derive from a variety of approaches.
Drive concepts for wind turbines
In a study comparing several drive concepts for wind turbines, energynautics analyzed weights, costs and efficiency of the different concepts. Even though the current standard capacity is 1.5 MW, the study also included turbines with a capacity of more than 5 MW (prototypes, small production runs) and even of up to 20 MW (research stage).
The analyzed drive concepts differed in several aspects:
- Generator type:
- Double-fed asynchronous generator (most common type)
- Electrically excited synchronous generator (especially common in Germany as direct drive [Enercon])
- Permanent-magnet excited synchronous generator (currently in small production runs as direct drive, will play an important role as high-speed generators in the future)
- Converter
- Full scale frequency converter for synchronous generators
- Partial scale frequency converter for double-fed asynchronous generators
- Speed
- Low speed generator (without gear box/direct drive)
- Medium speed generator (with one or two-step gearbox)
- High speed generator (with three-step gearbox)
energynautics used the general design of the generators to arrive at conclusions regarding the required weights and costs. In addition, we calculated the efficiency over the entire part-load range. Even during part-load, it is important to reach high efficiencies as wind turbines operate most of the time in this range. Depending on wind speed, they may only produce a small percentage of maximum power output.
Example: Superconducting generators
Another study analyzed high-temperature superconductor (HTS) generators and also comprised weight, cost and efficiency curve. Goal of the study was to understand at what point HTS generators can be expected to establish on the market. It was shown that rated capacity and the price development of the very expensive HTS material will be of decisive importance for this process.
Ziel der Studie war es, eine Aussage zu treffen, ab wann sich HTS-Generatoren auf dem Markt durchsetzen können. Das wiederum hängt ganz entscheidend von der Nennleistung und der Preisentwicklung des sehr teuren HTS-Materials ab.
energynautics included in the calculation the currently used material BiSCCO (1st generation of HTS material) as well as future materials that are still under development (YBCO, 2nd generation).
Example: Future development of wind turbines
Still another study carried out by energynautics analyzed the future development of wind turbines: Where is the limit, how large may wind turbines become?
This study was based on up-scaling; and particular emphasis was given to offshore developments, e.g. regarding various designs of foundations for offshore plants (fixed, floating).
It addressed some of large future challenges, for instance regarding the power supply of remote production sites.