International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 07 Issue: 10 | Oct 2020 www.irjet.net p-ISSN: 2395-0072 © 2020, IRJET | Impact Factor value: 7.529 | ISO 9001:2008 Certified Journal | Page 549 Effect of Cost on Load Dispatch of Hybrid Power System aiming Economy P.Sridevi 1 , Dr.B.Ravindranath Reddy 2 , Dr. Pannala Krishna Murthy 3 1 HEEES, Dept. of Tech. Education , Telangana, India 2 Deputy Executive Engineer, JNTUH, Hyderabad, Telangana, India 3 Principal, KITS, Khammam, Telangana, India ---------------------------------------------------------------------***---------------------------------------------------------------------- Abstract - Load Dispatch is the allocation of the load demand to the various generating units considering their various constraints so as to obtain the most economical operating costs. In a typical power system, several generators are interconnected to provide enough total output to satisfy a given total Load demand. Conventional sources like coal, which is the main source of power generation in India (and of course throughout the world) is fast depleting and also the cost of operation of Thermal power plant is more. Solar energy is freely available and the cost of operation of solar power plant is less. Hence In this paper 6 Thermal units are considered along with 4 solar (PV) units to meet the ever-increasing Load demands.A number of mathematical programming methods, Optimizing techniques and Modern BIA (Biologically Inspired Algorithms)were employed to solve Economic Load Dispatch problems.In this paper I am using solver add-in available in Excel and the results for various loads are compared. Since the Load demands are very complex and irregular in nature, this technique is used in solving the Load Dispatch problem by considering the fuel cost coefficients and transmission line losses for Thermal power plants and operating costs for Solar (Photo-voltaic) units. This technique arrives at the most economical solution to the problem. By integrating power obtained by Renewable energy sources to the grid, environmental pollution can be reduced, fossil fuels can be protected and also the freely available sources can be utilized in an optimum way. Key Words: Load Dispatch, Photo-voltaic, Fuel cost coefficients, Swarm Intelligence, Bio inspired Algorithms Krill -Herd algorithm, solver add-in. 1. INTRODUCTION Due to massive increase in demand of electricity, energy crisis has reached to its maximum degree all over the world in previous ten years. In today’s world the most difficult and important part is the interconnection of large generators in parallel in order to run the load economically and to full fill the load demands. Multiple number of generating units are connected and synchronized in parallel in order to ensure the proper working of large amount of load connected to the system these generators are connected to each other through a common copper bus bar. The primary objective of multiple generating units is to make sure safe and reliable working of the power system while keeping the operating and fuel cost of generating units to the minimum level possible. For this reason, optimized and timely switching of generating units is made possible to ensure maximum cost savings without affecting the load. Also there is a vast scope of the solar power generation in India due to the high solar irradiance index. The problem of economic load dispatch with the inclusion of the renewable power sources will reduce the load of generation on the thermal units and other fossil fuel units. Here in this paper we are including Photo Voltaic System (PVS) in consortium with thermal power generation units. If the input output characteristic curve of all the connected generators is same and identical to each other, then load can be symmetrically divided on all the generators connected in parallel. However, in most cases this is not the case. All or most of the generators connected are of different brands, having variable efficiency and dissimilar input output characteristics. All these generators will also have different fuel cost curves at different power outputs.. It increases the need of ELD to vary the power of generating units within the desired generating limits of each individual generator to meet output power demand within optimal fuel cost. Economic load dispatch is conducted to compute the operating cost of Hybrid power system through the strategic dispatch of electricity while fulfilling load demand. In this research, economic dispatch is conducted on 6 thermal units in combination with 4photovoltaic units. The basic economic dispatch will only consider real power generation. In this paper ELD problem is solved by ignoring emission, penalty constraint, prohibited operating zone, ramp-rates, and valve-point loading effect on thermal power generators and adding the factor of overestimation and underestimation of available solar power in power estimation section. Economic load dispatch involves computing the suitable generation level, and the resulting operating cost. Solar power can be forecasted and integrated into the Grid (e.g., GE Energy, 2008)