In an open-access environment, transmission constraints can result in different energy prices throughout the network. These prices are dependent on a number of factors such as the system load level, generating unit bid, demand unit bid, network topology and security limits imposed on the transmission network due to thermal, voltage and stability considerations. Computing these energy prices at all buses in large networks under given system operating conditions can be time consuming. This paper describes some simple methodology based on the computer programs to calculate saving , worth of transmission transaction, market clearing price, social welfare, transaction cost, locational marginal pricing, transmission capacity cost at selected zones for a given period. These information for energy prices can be used not only to improve the efficient usage of power grid but also to design a reasonable pricing structure of power systems or to provide economic signals for generation or transmission investment.