Innovation Norway has funded a theoretical analysis of the Subwave turbin. The analysis was conducted by Dr. Karl Christian Strømsem, Global Maritime AS, and presented in a report in September 2014. The analysis was based on the expected capacity of the turbine to convert wave energy from a coastal wave climate outside Karmøy on the west coast of southern Norway.
In the summary, Strømsem writes:
Analysis of the proposed system show that it will be necessary to increase the blade lengths substantially in order to achieve a reasonable energy capture with the device. An example show that increasing the blade length from 1 meter to 7.5 meter increases the energy capture from 2.5 % to 21.7 % of the incoming energy. Analysis using a typical near shore wave climate (Karmoy scatter diagram) gives a yearly production in the range of 150 MWh for a turbine with 5 meter long blades. The torpedo with the two turbine blade rings, counter acting generator kept away from the active wave zone is an interesting solution and addresses issues related to extreme loads and wave energy conversion without direct contact with the waves in an elegant way. A nice feature of the system is that it is easy to retrieve and maintain by simply disconnect and bring to shore.
In closing comments Strømsem writes:
Link to the report here (653 kB, pdf).