Lunar Energy is headquartered in the United Kingdom and specializes in what it calls Tidal In-Stream Energy Conversion or TISEC. The turbines themselves are actually developed by Rotech Engineering.
The key to the Rotech Tidal Turbine is the application of the venture duct, which accelerates tidal flows to increase the energy that can be captured. A venture duct is a static structure that uses the Venturi Effect to accelerate the flow of a fluid, in this case water, to ensure the maximum efficiency of the turbine. A system using a duct is able to produce roughly twice the energy output of a non-ducted turbine. The turbine itself is unremarkable and is based on a modified horizontal axis design.