Transmission system reactive power compensation

In the book Edited by T. J. E. Miller (Reactive Power Control in Electric Systems, John Wiley & Sons, 1982) the forward by Charles Concordia contains a perfect summary of why we must use reactive compensation: "...the transmission of active power requires a difference in angular phase between voltages at the sending and receiving points (which is feasible within wide limits), whereas the transmission of reactive power requires a difference in magnitude of these same voltages (which is feasible only within very narrow limits). But why should we want to transmit reactive power anyway? Is it not just a troublesome concept, invented by the theoreticians, that is best disregarded? The answer is that reactive power is consumed not only by most of the network elements, but also by most of the consumer loads, so it must be supplied somewhere. If we can\´t transmit it very easily, then it ought to be generated where it is needed." (Reference Edited by T. J. E. Miller, Forward Page ix). This paper discusses the transmission line requirements for reactive power compensation.