Impact of wind power on regional power balance and transfer

This report describes a method on how to analyse wind power influence on power transfer between different areas in a power system. It discusses how different aspects can be modelled and taken into account. Hourly consumption as well as conventional and wind power generation has to be predicted and modelled for each area for the whole period in question. In order to study the power transmission between the areas in a meshed system the influence of a given generation or load change on a given line flow should be studied by power flow calculation. In this report, an approximate method that can be used if the system can be reduced to a non-meshed or radial form is presented. The method is illustrated by fictitious examples of 0 MW, 2000 MW and 4000 MW of wind power installed in Finland. In order to get the generation units dispatched according to marginal costs, the market model Wilmar is used. The period of analysis is one year and the time step one hour. The impact of wind power on the power balance, power flow between the areas and congestion is calculated and analysed for the example cases. The main results from the calculated cases regarding transmission in Finland are that transmission across cut A (South Finland) is not congested, but a new transmission line over cut B (Middle part of Finland) might be economic in the wind scenarios due to increased transmission and congestions. Regarding the transmission between Finland and Sweden it was found out that situations with simultaneously high wind power production and high import will be rare as wind power will replace import to a large extent. Gererally, the more wind power there is in Finland: the more often is cut B congested, the more power is exported to Sweden over the AC-connection, the more often is Finland exporting power to Sweden.