“Vortex” Tidal Generator

In 2006 IDM Engineering were commissioned by inventor Chris Bradley from the green energy company E Motion, to build and test a prototype generator to be powered by tidal energy.

Working from a small model and a drawing; we successfully manufactured and tested a twentieth scale prototype generator measuring four meters by four meters.

From a desk top model to a fully tested working prototype.

The tidal generator named “Vortex” was manufactured so that it could be easily dismantled for transporting to the test site, enabling us to carry out testing on the River Dee whenever required.

IDM Engineering were not only responsible for the build but also planned and executed all of the testing, providing valuable local knowledge of the river, all vehicles, support boats and ancillary equipment.

On testing “Vortex.” We produced some fantastic results that far exceeded Chris’ hopes and expectations.

"Vortex" at the River Dee test site  

    Images taken from the the "Vortex" test run at the River Dee

"Comments from Chris Bradley the inventor"

The "Vortex" project was initiated to test the practicality and efficiency of a novel tidal turbine concept. The "Vortex" system uses a unique rotating blade geometry to present a continuously changing blade attack angle to the tidal stream, this enables the system to operate at high efficiencies in very low stream speeds. These low stream speeds are not suitable as a resource for existing tidal turbine concepts.

IDM engineering were commissioned to build, deploy and assist in the testing of the 10^th scale prototype on the tidal region of the River Dee. Building the prototype required a great deal of collaboration between myself and IDM, with innovative solutions needed for the adaptation of a concept to a working machine. The experience and creative input from IDM was invaluable during this phase of the project. The "Vortex" concept generates power from the tidal stream as a low speed rotating system, therefore the power output required measurement of torque and rotational speed. IDM built a variable load which ingeniously employed a motorcycle braking system which could apply an adjustable resistance to the shaft rotation. Using a strain gauge and instrumentation attached to the brake, the torque and therefore power output could be calculated.

Deployment of the floating structure onto the river was carried out by IDM with local knowledge of the river conditions being important to the safe launch, transport to the test site, testing and subsequent recovery of the prototype. IDM were able to provide a comprehensive service throughout the entire project, from construction through to deployment and recovery. Being able to work with a single organisation across many different aspects of the project meant that consistent lines of communication and understanding of the issues resulted in a very successful outcome.

The target for turbine efficiency at the planning stage was 10%. The results from testing on the Dee were far beyond this expectation, at around 30% conversion of tidal stream potential to power output. IDM played a central and critical role in the success of this trial." - Chris Bradley - EMotion Engineering MD