I am taking a course on AC circuits and so far I have seen that for the different types of power (read real, reactive and complex) different units are used.
For the real power, which is power in fact dissipated by the system, the SI compliant watt is used. I am very much in agreement with this.
However, for reactive and complex power the equivalent SI derived unit volt-ampere is used. In the special case of reactive power, a lowercase "r" is appended.
Now, I wonder: why should any other unit be used instead of watt, if the purpose of the unit is to specify the type of magnitude of a value? Moreover, why should a symbol be appended to the unit when its use is simply that of a reminder?
Also, is there a reason why using watts for reactive power would be considered wrong?