PI Mitterfellner


iPhone app iPI.App was developed by PI Mitterfellner and is available in the Apple Store since October 2012.


The iPI.App aims to provide anyone with an interest in hydro power with a quick and easy way of calculating approximate values when planning small hydro power stations.


Calculation functions:


Approximation of rated capacity, annual energy output and annual profit (iKWKW.opt has been developed based on the KWKW.opt® application)


Approximate calculation of ideal pressure pipe diameters


Approximate calculation of pipe friction losses for pressure pipes with up to three sections using the Prandtl-Colebrook formula


Approximate calculation of annual profits for small hydro power stations at market price or green energy tariff


The iPI.App is available as a free download from the Apple Store.

User interface

The iPI.App consists of four main calculation windows, each with four or five tabbed pages for editing, sending and configuring the data.

Technical description

Development Environment:
Xcode 5.0

Operating system:
iOS 6.1 (or later)