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 (simultaneous) similar energy use prediction operation utilising a second prediction technique; (d) correlating the results of the two techniques and; (e) providing a pass or fail signal depending on the level of correlation between the two techniques.