Chapter 10 focuses on the role of SEA in tidal power development. Tidal power, which harnesses energy from the movement of tides, is a promising but underdeveloped technology due to high costs and environmental challenges. Tidal energy can be generated through two main methods: tidal stream, which uses underwater turbines driven by marine currents, and tidal range, which utilizes the difference in water levels during tides via barrages or lagoons.
SEA helps identify environmental and socio-economic risks associated with tidal energy, such as changes to ecosystems, water quality and currents, as well as impacts on local communities. While tidal power can reduce greenhouse gas emissions, it can also lead to changed ecosystems and habitat loss, biodiversity disruption, and water contamination. Socio-economic impacts include the displacement of communities, job creation, and impacts on local fisheries. SEA is critical for managing these risks, recommending “no go” areas, and ensuring stakeholder involvement.
10.1 Why SEA is Important to Tidal Power
10.2 Existing SEA Guidance/Guidelines for the Tidal Energy Sub-Sector
10.3 Tidal Energy Installed Capacity
10.4 Background to Tidal Energy Generation
10.5 Impacts of Tidal Energy Development
Tidal power is a type of renewable energy that generates electricity by using the movement of ocean tides. There are two main ways to do this: tidal stream and tidal range. Tidal stream energy uses underwater turbines to capture the power of moving water, similar to wind turbines but underwater. Tidal range energy uses structures like barrages or lagoons to hold water during high tide and release it during low tide to turn turbines and generate electricity. While tidal power is more reliable than wind or solar, it is expensive and comes with environmental challenges.
Uses fast-moving tidal currents to turn underwater turbines. Turbines may be fixed to the seabed, suspended, or arranged in arrays. Power is carried to shore via undersea cables.
Uses barrages or lagoons to impound water at high tide. At low tide, the water is released through turbines to generate electricity. Includes barrage structures, embankments, turbines, control gates, and locks.
Strategic Environmental Assessment (SEA) is important in supporting the development and implementation of policies, plans, and programs (PPPs) concerned with renewable energy development, including those concerned with tidal power. It identifies environmental and social risks and potential impacts of PPPs. SEA also provides recommendations on how risks and negative impacts can be avoided or mitigated and how benefits can be maximized.
Environmental issues include ecosystem changes and habitat loss, harm to marine animals, and changes in water quality. For tidal range projects, SEA also helps assess changes to estuaries and tidal flows where altered mixing and sediment patterns can affect habitats. Tidal power systems can change water flows, reduce fish populations and other sea life, create noise that disturbs animals, and interfere with bird migration patterns.
Tidal power can also have social and economic impacts. While it creates jobs and boosts local economies, it can also displace communities and harm local fisheries, which many people rely on for their income. Fishermen and shellfish gatherers may lose access to important fishing areas due to tidal power infrastructure. Indigenous communities and vulnerable groups are at higher risk if their coastal resources are affected, and in some places, tidal power proposals may require free, prior and informed consent (FPIC).
SEA helps address these problems by identifying areas where tidal projects might cause too much harm and recommending areas to avoid. It also ensures early involvement of local communities and Indigenous groups, helping reduce conflicts and supporting fair and sustainable development.