1. A method of performing energy estimations operations in an intensive energy consuming site or system environment, the method comprising the steps of: (a) inputting a series of energy, emission and influencing data variables related to the intensive energy consuming site or system environment; (b) performing a first energy use prediction operation utilising a first prediction technique; (c) performing a second similar energy use prediction operation utilising a second different prediction technique; (d) correlating the results of the two techniques and; (e) providing an output signal indicative of the level of correlation between the two techniques.