The other day I stumbled upon a fascinating small scale hydropower plant - the 'gravitation water vortex plant' - as developed by the Austrian engineer Franz Zotloeterer, who holds the patent for the turbine technology.
The plant is transforming the mechanical energy produced inside a water vortex and has great potential for small scale installations. The maximum energy output for this technology is estimated to be about 150 kW at an efficiency of about 70% and a minimum falling height of 0,7 meters. [source]
The main pros of the 'gravitation water vortex plant' are:
- No regulation system necessary.
- Minor flotsam is able to pass the turbine.
- Fish can pass the plant in both directions.
- The water gets aerated leading to better microbial growth and breakdown of nutrient charge in water.
- The low falling height allows a better integration into the landscape.
Because of the above reasons this type of hydro power can be realized in relatively flat landscapes, integrated into river restorations (with synergistic effects) or included in wastewater treatment plants.
One may as well think about planning small gravitation water vortex power plants as being integrated in urban graywater discharge sewers. There they could create electricity used in pumping rainwater during storm events.
Three types of grid integration are presented on Zotloeterer.com:
- Parallel operation mode (direct injection into public power grid)
- Surplus energy into grid (energy not used by owner of plant is injected into public power grid)
- Isolated operation mode (energy is exclusively used by plant owner and stored in other means, eg hot water etc.)
There are several pilot projects in place already which demonstrate the feasibility of this technology.
Zotloeterer Inc. installed a pilot 'gravitation water vortex power plant' in Obergrafendorf, Austria, in 2006 .
The installation cost about 60.000 € and produces about 7,5 kW.
The first gravitation vortex power plant in Switzerland was inaugurated in 2010. The plant produces about 15 kW at an annual production of about 90000 kWh supplying 50 households with electricity.