PV System Sizing
The optimal choice of pv- module and components depends on many factors.
To determine the economic benefits of the system, cost of the system must be compared to the annual energy yield.
To do this the following process can be used:
- With the given site location, use a database to look up monthly average intensity values for both beam radiation and distribution.
- Determine if the panel can be tilted, or if not, what the tilt and azimuth angles are.
- Choose a pv-module. From the manufacturer's datasheet, look up the I-U- characteristics, temperature dependency and the module efficiency or peak wattage.
- Estimate user-losses from shading, snow and dirt.
- Select electrical components that can cope with the expected nominal power. Look up values for losses and mpp tracking quality from manufacturer's data sheets.
With all that input data, calculate nominal power and annual energy yield of the entire system.
This has to be repeated several times for the same location, but different pv- modules, inverters, mpp- trackers and wires. The energy yields of the different combinations must then be compared to the costs for the systems.