Kilowatts PV Spreadsheet
Kilowatts_PV_Spreadsheet is a spreadsheet designed to perform all the basic calculations involved in designing a stand-alone PV power system, including total power and energy needs, inverter and battery capacity, the number of PV modules required, and the regulator size. This is free open source software released under the GNU GPL license. Feedback and contributions to improve this software are welcome. The best place to start is the relevant Kilowatts Forum.
CURRENT VERSION: 1.0
DOWNLOAD: kilowatts-pv-spreadsheet-1.0.tar.gz (zipped TAR archive)
Package Contents
The download package includes the following files:
- Kilowatts_PV_Spreadsheet-1.0.ods - (OpenOffice Format)
- Kilowatts_PV_Spreadsheet-1.0.sxc - (Older OpenOffice Format)
- Kilowatts_PV_Spreadsheet-1.0.xls - (MS Excel Compatible Format)
- LICENSE.txt - (license information: GNU GPL v3)
- README.txt - (usage information)
Usage Information
The spreadsheet is divided into 4 sections. Sections 1 and 2 require user input. Fields which require user input have a yellow background.
Section 1:
- Concurrent Load Factor: How much of the total possible load can be expected at any pont in time? Ranges from 0 (none) to 1 (100%). 50% would be 0.5.
- Inverter Efficiency Factor: Inverter efficiency. Typically 0.85 (85%) to 0.9 (90%).
- System Voltage: Typically 12, 24 or 48 volts in residential ELV systems.
- Days of Autonomy: How many days should the system continue to provide energy without input (due to bad weather, etc).
- Daily Depth of Discharge: The acceptable depth of battery discharge each day. Typically 10% to 50%. Discharging batteries beyond 50% is not recommended.
- Battery Efficiency Factor: The efficiency of the battery system. Typically 0.8 (80%) to 0.9 (90%).
- Peak Sun Hours (PSH): The number of Peak Sun Hours per day.
- PV Module Wattage: The desired PV module wattage. Could be anything from 50W to 200W.
Section 2:
In section 2, the total energy demand to be supplied by the system is calculated. Section 2.1 details AC loads while Section 2.2 details DC loads. Lines will need to be added to this section as required for each appliance. The existing data is used as an example only.
The formulas used can be viewed by clicking on a cell and then viewing the bar at the top of your spreadsheet program.