Researchers from the Universidad Politécnica de Madrid (UPM) have developed a tidal generator and anchoring systems that reduces the cost of harnessing deep sea tidal power.

Members of the Technological Research Group in Marine Renewable Energy (GITERM) at UPM assessed the life-cycle cost of a power generation park and used economic analyses and simulations to develop new anchoring systems that are simpler and more robust in design.

The device, named GESMEY, has evolved from generators with one large rotor to generators with several rotors. This reduced the estimated cost of energy production by 30%.

“Our GESMEY device, patented by the University, has been the first design worldwide tested in the sea and fit to operate fully submerged,” said School of Naval Engineering at UPM researcher Amable López.

“Thanks to the cost analysis tool, we were able to assess diverse design alternatives with a final goal: to reduce as much as possible the production cost of the energy and to make this renewable source both financially and technically competitive, helping fight against climate change.”

Experts agree that the next step for offshore renewables is harnessing the energy from the power of the tide.

It is estimated that 80% of tidal energy is located in areas of over 40 metres depth. At such depths, it is expensive to install first generation devices on the seabed. Second generation systems have anchors and a series of cables that ensure it remains anchored to the seafloor.

The research group is working to achieve successful commercialisation of renewable tidal energy.

“The energy from currents is a renewable source that has an additional value in a future energy market regarding other renewable energy sources due to its high predictability,” said researcher José Andrés Somolinos.

“Besides, tidal energy technologies are characterised by a CO2-free energy that contributes to the economic growth and job creation in coastal and remote areas.”

The results were published in the Renewable and Sustainable Energy Reviews.