NEMMO

NEMMO Next Evolution In Materials and Models for Ocean Energy.
The energy sector must drastically reduce the cost of technologies to achieve grid parity and with the objective of reaching a levelized energy cost of 0.15 euros/kWh in 2025 and 0.10 euros/kWh in 2030 for tidal energy.

Problem

The NEMMO project seeks to generate the necessary knowledge to implement a robust design and verification methodology to develop larger, more efficient and longer-lived advanced composite turbine blades for tidal power generation.

By 2050, energy sources in Europe must be renewable. Achieving this goal involves harnessing the energy generated by the sea, increasing the energy efficiency of the turbines through design improvements and new materials. So relevant is the fact that the EU has set the ambitious target of reaching 100 gigawatts of installed tidal and wave power capacity by 2050.

Tidal turbine blades suffer from the effects of aging, fatigue, ‘bio-fouling’ – accumulation of microorganisms, plants, algae, or animals on wet surfaces – and cavitation erosion that cause turbines to lose their energy efficiency.

When turbines are operating at their maximum power, they suffer especially from the hydrodynamic phenomenon of cavitation: when water passes at high speed over the sharp edges of the blades, it can vary the pressure so much that it immediately changes to a vapor state. The bubbles (cavities) that form travel to areas of higher pressure and implode: the vapor suddenly returns to the liquid state. The bubbles are ‘crushed’ abruptly and produce a gas wake so strong that, in the collision, it can crack the blade.
Through simulation, new systems and components for active flow control can be designed that will mitigate cavitation and increase the performance and energy efficiency of marine turbines.

Results

The main expected results of the NEMMO project are:

• New simulation tools for modeling the operation of turbine blades for tidal power generation, including the instantaneous definition of cavitation phenomena.
• Fatigue behavior, hydrodynamic performance, aging, bio-fouling and cavitation wear models.
• Novel test equipment and methodology for the evaluation of bio-fouling, aging, fatigue and cavitation erosion.
• Active Flow Control system, biomimetic surfaces and nano-enhanced composites and coatings for high-performance tidal turbine blades.
• Design methodologies to develop turbine blades made of advanced composite materials that improve hydrodynamic performance, durability and resistance to marine environments.
• Manufacture of 1:1 scale blades in optimized composite materials according to the findings of the NEMMO project.
• Full-scale testing for complete characterization and evaluation of the optimized design, including a first test of the tidal cycle in a full-scale offshore demonstrator.