Large-scale Integration Of Wind Energy Research Articles

Wind Integration in Power Systems: Operational Challenges and Possible Solutions

This paper surveys major technical challenges for power system operations in support of large-scale wind energy integration. The fundamental difficulties of integrating wind power arise from its high inter-temporal variation and limited predictability. The impact of wind power integration is manifested in, but not limited to, scheduling, frequency regulations, and system stabilization requirements. Possible alternatives are suggested for a more reliable and cost-effective power system operation. New computationally efficient methods for improving system performances by using prediction and operational interdependencies over different time horizons remain critical open research problems.

Power grid balancing of energy systems with high renewable energy penetration by demand response

It is generally accepted that the integration of intermittent energy resources like wind energy and photovoltaics into an electricity system cannot exceed a limit of around 20% or 25%, see, e.g. [EWEA, 2005. Large-scale integration of wind energy in the European power supply: analysis, issues and recommendations. The European Wind Energy Association]. However, the decoupling of electricity generation and consumption cannot be implemented only by use of electricity storage. In the end, electricity is converted into many different energy services – quite often into thermal energy – which is better suited for storage. This article presents the results of investigations which studied the potential of those demand response activities for Germany. The investigations are based on both modelling of thermal storage devices and laboratory tests.

THE AVAILABILITY AND VARIABILITY OF THE EUROPEAN WIND RESOURCE

The purpose of this paper is to show the differences in the availability and variability between the wind at individual sites and the wind taken over a European scale. One of the questions this paper will try to answer: ‘is there a benefit from having wind farms covering a large area’, has been asked a number of times in the discussion about the usefulness of large-scale integration of wind energy. A European wind is made up of normalized stations scattered all over Europe scaled with a factor determined from the European Wind Atlas[4].

A numerical model for calculating the power output fluctuations from wind farms

One of the main problems of large-scale wind energy integration is the maintenance of high quality of supplied electric energy, due to the variability of the power output from wind energy systems, which may lead to large frequency and voltage fluctuations in the grid. To control this problem, knowledge is required about power output fluctuations of wind energy systems. Hence there is a strong need for an accurate prediction of these fluctuations. This paper describes a model with which the time dependent power output from wind farms can be calculated. First, an outline is given of relevant fctors in relation to the time dependent behaviour of wind farms. Second, the developed model is described. Third, an example calculation is given which illustrates the time dependent behaviour of a wind farm in ‘bad weather’ conditions. The paper ends with suggestions for further developments of the model in relation to possible applications.