The study demonstrates the possibility to use the notions and tools of physical potential theory in development of a general theory of economic potential. Production functions and functional of consumer or managerial preferences are treated as microeconomic potential functions. The gradients of these functions i.e. marginal utilities and products can be regarded as power functions. A degree of returns to scale is considered as an indicator of magnitude of microeconomic potential. The study outlines general approaches to equilibrium analysis under increasing returns to scale. The hypothesis of profit maximization for a competitive firm proves to be inadequate and must be replaced by more simple objectives such as output and revenue maximization or cost minimization subject to correspondingly financial or capacity utilization constraints. The study develops the existing concepts of general competitive equilibrium under various types of returns to scale typical to potential (production and utility) functions of economic agents.