Wind Power in Areas with Limited Transmission Capacity

Historically, transmission systems are built together with power production installations in order to meet the expected electricity consumption. For economic reasons, they are usually not overdimensioned and therefore cannot guarantee power transmission capacity for new power plants for 100% of the year. Wind power plants have to be installed in the immediate proximity of the resource – wind. The best conditions for an installation of wind power can usually be found in remote, open areas with low population densities. The transmission system in such areas might not be dimensioned to accommodate additional large-scale power plants. The thermal limits of the conductors, voltage and transient stability considerations restrict transmission capability during extreme situations, such as during low local loads and high wind power production. This chapter covers the issues concerning the integration of new generation (particularly from wind power) in areas with limited transmission capacity. We will start in Section 20.2 with an overview of different congestion types and some conventional measures to overcome them. In Section 20.3 we present different approaches used by transmission system operators (TSOs) to determine transmission capacity. In Section 20.4 we look at ‘soft’ and ‘hard’ grid reinforcement measures to increase transmission capacity. The problems associated with the integration of new wind generation in areas with limited transmission capacity are discussed in the Section 20.5. In Section 20.6 we present methods to estimate the amount of wind power that can be integrated in areas with limited transmission capacity before grid reinforcement becomes the more