TABLE OF CONTENTS The connection of wind farms into distribution and transmission systems will have a local effect on voltage levels and reactive power flows, as discussed in the preceding chapters. The primary objective, however, of this network infrastructure is to deliver active power economically and reliably from generation sources to individual loads scattered across a national area. One of the underlying characteristics of electricity supply, which profoundly affects the manner in which it is engineered, is that electrical energy cannot be stored conveniently or economically. The consequence of this statement is that, ignoring any losses incurred in the electricity transmission network, there must be an instantaneous balance between the electrical power generated and the system demand.
This chapter first examines how conventional generating units can be scheduled and operated to cope with variations in the demand under both normal and emergency conditions (Section 5.2). The inclusion of wind generation in this task creates potential problems, as the power output of individual turbines is subject to time varying weather patterns. Section 5.3 begins by presenting a status report on how various countries are addressing the challenges (Section 5.3.1). Then, taking the island of Ireland as an example, the variability of wind output on different geographical scales and operational timeframes is examined in detail (Section 5.3.2). Various key problems of wind power integration on a significant scale, with some current solutions, are discussed in Sections 5.3.3 5.3.8. Wind forecasting is a useful tool, in this respect, and its potential role is discussed...
