Economic load dispatch (ELD) is a complicated issue, when renewable energy sources are also considered with thermal power generation systems. It becomes challenging and difficult to find the optimum solution at lower fuel costs, in order for generated power to meet the active power load demand. This paper primarily focuses on the modeling of ELD for solar power plants synchronized with Thermal power plants. In this paper, the purposed optimization method used is Genetic algorithm (GA). According to which, all thermal generators in the system will supply output power at lowest fuel rate however satisfying the system limitations. Minimum fuel cost of a generator will be calculated by using generator characteristic curve for all generators present in the system. With the help of GA, achievable range for best solution is attained while restricting the output power of thermal generators. Proposed system priority to achieve is solar at first and generators on second such that generator or combination of generators resulting in lowest cost will be on second priority. Simulations on various test systems were performed including one with six thermal generators and the other with six thermal generators and solar power system. By using MATLAB the proposed problem is simulated.

A scheme has been proposed, modeled and simulated to show an improved system efficiency, battery life and payback period of a 340 kWp peak power grid interactive solar photovoltaic system. In this case, a conventional solar photovoltaic system capable to fulfill 66% energy demands has been modified to meet complete energy demands without an increase in system's photovoltaic capacity. It has been shown via modelling and simulation on PVSyst that using direct current appliances instead of alternating current appliances, initial power demands are reduced by 58% and conversion losses (DC-AC-DC) of 9.6% are eliminated. These modifications result in an overall increase in the system's performance ratio from 73.8 to 83.4%, with an increase in energy production from 469.6 to 557.9 MWh. As an outcome, battery life is increased by 1200 duty cycles as the depth of discharge is reduced from 35 to 26%.