There are a wide variety of software packages for designing and sizing of solar PV system. However, all of them are at the commercialized level which is more sophisticated and costly. This paper presents a simplified designing tool for array configuration of the grid-connected solar photovoltaic (GCPV) system. A simple, free and user-friendly tool known as PV.xls was developed to determine the array configuration of a GCPV system which can be applied for green housing. This tool was created for educational purposes to assist those with a limited technical background to design and size the system. The tool uses a basic simple Microsoft Excel spreadsheet. Database of PV modules, inverters, and simplified sizing procedure for the calculation of array configuration is embedded in the spreadsheet. The calculation is based on Malaysia Standard MS1837:2010