🌊Tidal and Wave Energy Engineering Unit 15 – Future Trends in Tidal & Wave Energy

Key Concepts and Terminology

• Tidal energy harnesses the power of ocean tides caused by gravitational forces of the moon and sun
• Wave energy captures the kinetic energy of ocean surface waves driven by wind
• Tidal range is the vertical difference between high and low tides, a key factor in tidal energy potential
• Wave height, period, and direction are crucial parameters for determining wave energy resource
• Capacity factor represents the ratio of actual energy output to the maximum possible output over a given period
  • Tidal and wave energy systems typically have higher capacity factors compared to solar and wind
• Levelized cost of energy (LCOE) measures the average net present cost of electricity generation over a system's lifetime
• Tidal barrage involves constructing a dam-like structure across a tidal estuary or bay to capture tidal energy
• Tidal stream turbines resemble underwater wind turbines and extract energy from tidal currents

Current State of Tidal and Wave Energy

• Tidal and wave energy are still in the early stages of development compared to more mature renewable technologies like solar and wind
• A few large-scale tidal barrage projects are in operation (La Rance, France and Sihwa Lake, South Korea)
• Tidal stream and wave energy technologies are mostly in the demonstration and pilot project phases
• The United Kingdom, France, Canada, and South Korea are leading countries in tidal energy development
• Scotland hosts the world's largest tidal stream array, the MeyGen project, with a planned capacity of 398 MW
• Australia, the United States, and several European countries are actively pursuing wave energy research and development
• Tidal and wave energy currently contribute a small fraction of global renewable energy production
  • Estimated global installed capacity of 500 MW for tidal and 25 MW for wave energy as of 2020

Emerging Technologies and Innovations

• Floating tidal turbines can be deployed in deeper waters and are less impactful on marine environments compared to seabed-mounted turbines
• Oscillating water column (OWC) wave energy converters use the rise and fall of waves to compress air and drive a turbine
  • The Mutriku Wave Energy Plant in Spain is a successful example of an OWC system
• Attenuators are long, snake-like wave energy devices that flex and bend with the motion of waves to generate electricity (Pelamis)
• Point absorbers are buoy-like devices that move up and down with waves, driving a generator (PowerBuoy)
• Overtopping devices allow waves to spill over into a reservoir, with the water then released through a turbine (Wave Dragon)
• Hybrid systems combine multiple renewable energy technologies, such as floating solar panels with wave energy converters
• Advancements in materials science, such as the use of composite materials and polymers, can improve the durability and performance of tidal and wave energy devices
• Artificial intelligence and machine learning techniques are being applied to optimize device design, control systems, and maintenance strategies

Efficiency Improvements and Cost Reduction

• Increasing the scale of tidal and wave energy projects can lead to economies of scale and reduced costs
• Standardization of device designs and components can streamline manufacturing processes and lower production costs
• Advancements in power take-off systems, such as direct drive generators and hydraulic systems, can improve efficiency and reliability
• Optimizing device arrays and layouts can maximize energy capture and reduce wake effects
  • Numerical modeling and computational fluid dynamics (CFD) simulations aid in array optimization
• Improved foundation and mooring designs can reduce installation and maintenance costs
• Predictive maintenance techniques, such as condition monitoring and data analytics, can minimize downtime and extend device lifetimes
• Collaborative research and development efforts, such as the European Marine Energy Centre (EMEC), facilitate knowledge sharing and cost reduction strategies

Environmental Impact and Sustainability

• Tidal and wave energy have a lower carbon footprint compared to fossil fuel-based energy sources
• Tidal barrages can affect fish migration patterns and sediment transport in estuarine ecosystems
  • Fish-friendly turbine designs and fish passages can mitigate these impacts
• Tidal stream turbines may pose risks to marine life through collision, entanglement, and changes in hydrodynamics
  • Careful site selection, monitoring, and adaptive management strategies can minimize negative impacts
• Wave energy converters have minimal visual impact on coastal landscapes compared to onshore wind turbines
• Underwater noise generated by tidal and wave energy devices may affect marine mammal communication and behavior
  • Proper device design and operational protocols can reduce noise levels
• The use of eco-friendly materials and decommissioning plans contribute to the overall sustainability of tidal and wave energy projects
• Environmental impact assessments (EIAs) and ongoing monitoring are crucial for ensuring the long-term sustainability of tidal and wave energy development

Integration with Existing Energy Systems

• Tidal and wave energy can complement other renewable energy sources like solar and wind to provide a more stable and reliable power supply
• Hybrid systems that combine tidal or wave energy with energy storage technologies (batteries, hydrogen) can help balance supply and demand
• Integration with smart grid technologies enables efficient distribution and management of tidal and wave energy resources
• Coupling tidal and wave energy with desalination plants can provide both clean energy and freshwater in coastal regions
• Offshore transmission infrastructure, such as high-voltage direct current (HVDC) lines, facilitates the integration of tidal and wave energy into onshore power grids
• Collaborative planning between energy developers, grid operators, and policymakers is essential for successful integration
• Developing accurate forecasting models for tidal and wave energy production aids in grid integration and energy market participation

Policy and Economic Factors

• Government support through funding, subsidies, and tax incentives is crucial for the growth of the tidal and wave energy sector
• Feed-in tariffs and renewable energy certificates can provide financial incentives for tidal and wave energy producers
• Establishing clear and consistent regulatory frameworks for permitting, licensing, and environmental impact assessments streamlines project development
• Public-private partnerships can help share risks and costs associated with tidal and wave energy projects
• Developing local supply chains and creating jobs in the tidal and wave energy sector can contribute to economic growth in coastal communities
• International cooperation and knowledge sharing, such as through the Ocean Energy Systems (OES) initiative, can accelerate the commercialization of tidal and wave energy technologies
• Incorporating tidal and wave energy into national and regional renewable energy targets and climate change mitigation strategies drives policy support

Challenges and Future Research Directions

• Improving the reliability and survivability of tidal and wave energy devices in harsh marine environments
• Developing cost-effective and efficient energy storage solutions to address the intermittency of tidal and wave energy
• Enhancing the accuracy of resource assessment and forecasting models to optimize site selection and device performance
• Investigating the potential for tidal and wave energy to provide ancillary services, such as grid balancing and frequency regulation
• Exploring the co-location of tidal and wave energy with other marine activities, such as aquaculture and coastal protection
• Developing innovative materials and coatings to prevent biofouling and corrosion of tidal and wave energy devices
• Studying the long-term ecological impacts of tidal and wave energy projects and developing best practices for environmental monitoring
• Engaging with local communities and stakeholders to address concerns and promote public acceptance of tidal and wave energy development