Abstract: This project develops efficient algorithms by using firefly and differential evolution algorithm to minimize Economic Dispatch, NOx Emission Dispatch and Combined Economic and Emission Dispatch problems in thermal power plant. The thermal power plants pollute air, soil and water. Due to this, the present energy production processes are not ecologically clean. The combination of fossil fuels gives rise to particulate materials and gaseous pollutants apart from discharge of heat to water courses. The three principal gaseous pollutants, namely carbon-dioxide, oxides of sulfur and nitrogen cause detrimental effects on human beings. This harmful ecological effects caused by the emission of particulate and gaseous pollutants can be reduced by adequate distribution of load between the plants of a power system. But, this leads to a noticeable increase in the operating cost of the plants. For successful operation of the system subject to ecological and environmental constraints, algorithms have been proposed for minimum cost, minimum NOx emission and combined economic and emission dispatches. These are based upon quadratic type objective function and the solution gives the optimal dispatch directly. In the present work, a price penalty factor is introduced which blends the emission cost with normal fuel cost. This avoids the use of two classes of dispatching and the need to switch over between them.

Keywords: Firefly Algorithm (FFA), Differential Evolution (DE).