Welcome to Task 25 Summary Page

Power Systems with
Large Amounts of Wind Power

Technical Research Center of Finland VTT

OA Representative:
Dr. Hannele Holttinen
Senior Research Scientist, Team Leader Wind energy
VTT, Technical Research Centre of Finland
P.O.Box 1000, FIN-02044 VTT
Tel./Mob: +358 20 722 5798
Fax: +358 20 722 7048
Email: hannele.holttinen@vtt.fi
Web Site: Task 25 Power Systems With
Large Amounts of Wind Power

Although wind power has the potential to supply large amounts of clean, renewable electricity, it will introduce more uncertainty into operating a power system; it is variable and partly unpredictable. To meet this challenge, there will be need for more flexibility in the power system. How much extra flexibility is needed depends on the one hand on how much wind power there is and on the other hand how much flexibility already exists in the power system.

The ultimate objective of IEA Wind Task 25 is to provide information to facilitate the highest economically feasible wind energy penetration within electricity power systems worldwide. This task supports this goal by analysing and further developing the methodology to assess the impact of wind power on power systems. The Task has established an international forum for exchange of knowledge and experiences related to power system operation with large amounts of wind power. The challenge is to create coherence between parallel activities with Transmission System Operators other R&D Task work.


Figure 1 Impacts of wind power on power systems, divided in different time scales and width of area relevant for the studies. Primary reserve is here denoted for reserves activated in seconds (frequency activated reserve; regulation) and Secondary reserve for reserves activated in 5–15 minutes (minute reserve; load following reserve).

The participants are collecting and sharing information on the experience gained and the studies made so far. The case studies produced are based on this information and will address different aspects of power system operation and design, including reserve requirements, balancing and generation efficiency, capacity credit of wind power, efficient use of existing transmission capacity and requirements for new network investments, bottlenecks, cross-border trade, and system stability issues. The main emphasis is on the technical operation of the power system. Costs will be assessed when necessary as a basis for comparison. Also technology that supports enhanced penetration will be addressed: wind farm controls and operating procedures, dynamic line ratings, storage, demand side management, etc.

The task work has started with a state-of-the-art report collecting the knowledge and results so far (see Task 25 Web site). The task will developed guidelines on the recommended methodologies when estimating the system impacts and the costs of wind power integration. Also, best practice recommendations will be formulated on system operation practices and planning methodologies for high wind penetration. The Task will continue through 2011. For the latest information, please visit the Task 25 Web site.