BB200702, News in Brief
European Power Blackout: Was Wind Responsible?
Last November’s major disturbance across the European grid was “the most severe disturbance in its history”, according to UCTE, the union of transmission system operators (TSOs). Prompted by the intentional temporary closure of a power line in order to enable the safe passage of a cruise ship on the River Ems, the resulting interruptions in supply caused blackouts for more that 15 million households in the western part of Europe. The consequences were system wide, and resulted in a temporary division of the UCTE grid into three ‘islands’, each with significant power imbalance.
Fortunately, the recovery of the system – effected both by automatic and manual interventions - was relatively fast. In less than two hours a normal situation was re-established in all European countries. Because the initiating event happened in a North German region which has lots of wind farms, however, some accusing fingers were quickly pointed in the direction of wind power. Closer examination showed this to be unjustified.
UCTE itself set up an investigating committee to undertake an in-depth analysis of the disturbance. This involved a detailed examination of the sequences of grid events all over the European power grid and a search for the root causes. The final report, released at the end of January, gives an analysis of the basic root causes and further critical factors, and formulates recommendations. The European Regulators Group for Electricity and Gas (ERGEG) also carried out a detailed evaluation of the event, and published an interim report which pointed to major legal and regulatory gaps in Europe’s electricity market.
The system disturbance in fact provided a showcase of the strengths and weaknesses of the operation of the European grid, including its regulatory and legal framework, as it progresses towards becoming more prepared for the internal electricity market. A repeat could be avoided in the future by improved regional and international co-ordination of TSO operations, as well as by enhanced data exchange and communication procedures. This should be backed up and enforced by substantial improvements in the legal framework and regulation at a European level.
Wind power was not at all responsible for this major grid disturbance. The two main causes were identified by the UCTE as a) “non-fulfilment of N-1 criterion” (breaking the handbook rules) and b) insufficient inter-TSO co-ordination. On the other hand, the presence of wind power in the grid, as for all other users and generators, had an influence on what subsequently happened. In its list of recommendations in the final report, UCTE suggests an adaptation of the regulatory or legal framework to maintain better control over the grid in future. A number of these directly affect the design and operation of wind power plants, notably control by TSOs over generation output and more stringent requirements for design and operation of generation units connected to distribution grids. In the view of EWEA it is essential that the development of new regulations should be done in close co-operation with the wind power industry to arrive at efficient and economically justified measures and solutions.
For more information: The UCTE and ERGEG reports are available at www.ucte.org/pdf/Publications/2007/Final-Report-20070130.pdf; www.cre.fr/imgAdmin/1166636916711.pdf