Electric power is substantially an important resource in the modern world. With the increase in demand for electric energy, there is a need to search for alternative energy sources because conventional resources are being exhausted. This results to significant increase in electricity cost. Use of green energy as an alternative to the conventional generation of electricity is currently on the rise. This study presented modeling and energy management of a grid-connected solar PV system aimed at reducing electric energy cost to an ordinary consumer in Kenya. Electricity cost is one of the top expenses of the ordinary consumer. The study was conducted at Murang’a University of Technology, Kenya. MATLAB Simulink software was used for modeling. Arduino Uno was chosen to perform real-time energy management that involved switching between the micro sources and the grid when the supply current from the micro sources dropped below a defined threshold value. Arduino microcontroller used instantaneous method of calculating current, voltage and power. An Application Programming Interface was proposed for forecasting energy production from the solar Photovoltaic system. Significant savings in electric energy bill was expected with the proper application of the Energy Management System in a smart house. The prototype developed managed to disconnect the loads one at a time and reconnect the particular load to the grid whenever the supply current from the micro sources dropped below the specified threshold value.