Global demand for energy production is in an increasing trend. However, a gap between energy production and energy demand still represents an industrial challenge. Iraq, like too many developing countries, is an example of such problematic. To tackle these issues, renewable energy could be a valid solution. Renewable energy becomes necessary especially the unique location of the received solar energy and long daylight. Many pieces of research deal with maximum benefit from this condition. This paper discusses the design stand-alone PV system for one home in Baghdad and sizing all components in that system start with energy demand, inverter power, PV, battery bank, and connections with each other by design a simple calculation program. Computational modeling was performed to evaluate different designs. Cost efficiency of system performance based on the domestic market prices was estimated and compared with electrical provide from conventional electrical plants (grid and local generator).