In this paper we consider the use of exergy in economic valuation and its correlation with money. Exergy-based determination of production expenses provides a new base for "natural" price determination. A new macroeconomic dynamics approach based on this correlation is proposed. This method is relatively general because it is not restricted by certain assumptions used in traditional economic analysis. The exergy model of macroeconomic dynamics was tested by the utilizing data from the US economy. This test, covering a period of about 25 years, confirms this approach and opens new potentials in economic analysis.