Full-scale initial engineering of Tidetec’s turbine shows 11% efficiency gain

The Norway-based tidal energy technology developer, Tidetec, recently carried out an initial engineering for a 20MW turbine system with a 7m diameter turbine runner. The analysis has shown an efficiency gain of 11% in addition to cost reductions for the complete system of 6-9%.

Tidetec has conducted the initial engineering together with engineering companies FEMKUBER and HUGG.

Full-scale engineering of the turret shows a weight of approximately 270 tonnes, the dimensioning of the steel structure is well within fatigue limits, given an operation time of 50 years, the technology developer explained. The cost calculations show a cost reduction of the total system, even with an added turret cost. This is due to the turning mechanism which only adds around 4-7% and the turret allows for a much simpler and cost effective runner design. The Straflo turbine design uses less materials than a conventional bulb turbine – thus allowing for cost savings on the materials.

Given the results of the analysis and after being mentioned specifically as a promising solution for both cost reduction and efficiency gain in the Hendry review, Tidetec has had a very good start of 2017, the company said. “We are more confident than ever regarding our solution – this will have a significant impact on the profitability of the proposed Tidal lagoons in UK.”

Tidetec added that, in addition to the full-scale engineering of the turret, it stands “on more solid ground” regarding turbine and pumping efficiencies, as the Technical University in Munich have conducted simulations on the turbine system. “Plant production simulations show an unmatched performance compared to today’s turbine solutions. These simulations are based on the turbine efficiencies, flow rates in both pumping and turbining mode, and a set operational regime for the tidal power plant.”

The efficiencies will be confirmed through laboratory testing of Tidetec’s model turbine at the Technical University in Munich in the second quarter of 2017.

In November 2016, the company concluded a two-month long testing of its prototype tidal device in Svelvik, Norway, with the device working without any technical issues during the entire test period.