Otter – Inline Hydro Turbine

The Challenge

Design a turbine to fit into existing pipework that can operate with a back pressure. This configuration is ideal in a distribution pipeline, where excess pressure is available. Our goal is to design a low-cost inline unit that can be used to access the available energy. Our team of engineers developed The Otter as an original design concept based on years of turbomachinery experience.

Unique design

We started with a prototype to proof the concept, using a unique integrated rotor design. A dedicated test bed was designed and built for testing the concept as well as the first prototype. The prototype test results were very encouraging, and we proceeded to design the first prototype for long term testing. In addition to the rotor design, a fixed flow path geometry was used, and the shaft was designed to run in water lubricated bearings. The prototype design was a unique layout using only basic components. The generator output is controlled by variating the load with an automatic system that will dump load to a load bank and maintain output frequency. The prototype unit generates 400 V and is not grid connected. Various configuration options are possible.

Field Application

The final step for a development project is to find a suitable site to build a track record outside of a test environment. An ideal opportunity presented itself on our doorstep at a new reservoir. The design of the new reservoir provided for a turbine in parallel to the pressure control valves. The turbine provides essential power to the reservoir. We record detailed information on all the operating conditions, as well as vital turbine performance parameters. This data will be valuable in the design of a planned next model.

The prototype is designed to deliver a maximum of 12 kW at 20 m head. This design could easily be scaled to larger units and we are exploring various options.

Closed loop Test Bed	Proof of Concept unit
Reservoir Installation