As a result of the gas pressure drop in natural grid pipelines in the cold seasons, the feedstock of steam power plant is changed from the natural gas into the heavy fuel oil. Sometimes this change happens for the whole winter and causes lots of environmental problems for the cities near the big power plant. Gasification is a technologically advanced and environmentally friendly process of disposing the heavy fuel oil and the coal by converting them into the usable gas products named Syngas which mainly consists of CO and H-2. In this article, the feasibility study of gasification process application in the available steam power plant is considered. The 1000 MW steam power cycle is simulated and the natural gas, heavy oil, and generated syngas from gasification process of heavy fuel oil are selected as the feedstock. Results of economic analysis illustrate that in current economic conditions, the application of gasification process is not feasible in the available steam power cycle. It also shows that in the higher market prices of electrical energy, the revenue of system is much more than the emission penalty cost. So the difference between two types of calculation (considering emission penalty cost) is not noticeable. (C) 2015 Elsevier Ltd. All rights reserved.