Ocean Energy

Fast Facts About
Ocean Energy

Principal Energy Use: Electricity
Forms of Energy: Kinetic/Thermal

Ocean energy, also known as marine energy or hydrokinetic energy, is an abundant renewable energy resource that uses ocean water to generate electricity. The majority of ocean energy technologies are still in research and development. While the potential of ocean energy is great, it faces significant technological, environmental, and financial challenges and has low levels of investment.

There are four main types of ocean energy systems:

1. Tidal Barrage Systems are dam-like structures built across ocean inlets to form a tidal basin. Installed turbines inside the tidal barrage let water in to fill up the basin during times of high tide, and let the water flow out during times of low tide, generating electricity in both directions.
2. Tidal Stream (or Tidal Current) Systems use electrical generators installed directly into the stream of water, similar to placing wind turbines underwater. As water flows through the generators, they harness kinetic energy of the water and convert it into electricity.
3. Wave Energy Systems use the motion of waves to run a system that converts the mechanical energy of wave motion into electrical energy.
4. Ocean Thermal Energy Conversion (OTEC) takes advantage of the temperature difference between warm surface water and much colder water at depth to power a turbine in a closed-loop system that can generate electricity

The statistics in this Fast Facts only include data for countries that participate in the Ocean Energy Systems (OES) organization under the IEA. Here is a complete list of member countries.

Significance

* _{The US does not have any operational ocean energy capacity. All US marine energy projects are installed in river inlets and are accounted for on our Hydropower page.}

World

Capacity of Largest Operational Ocean Energy Projects

The two tidal barrage plants represent 96% of the 513 MW of 2023 installed capacity.

*_{NIMBY - not in my backyard; BANANA - build absolutely nothing anywhere near anything}

Climate Impact: Low

• Near zero emissions

Environmental Impact: Medium

• No air pollution, but potential for significant impact to marine species and their habitats
• Collision of marine life with underwater turbines
• Creation of underwater noise pollution
• Habitat changes

Our Lecture on
Ocean Energy

This is our Stanford University Understand Energy course lecture on ocean energy. We strongly encourage you to watch the full lecture to understand ocean energy as an energy system and to be able to put this complex topic into context. For a complete learning experience, we also encourage you to watch / read the Essential videos and readings we assign to our students before watching the lecture.

Presented by: Diana Gragg, PhD; Core Lecturer, Civil and Environmental Engineering, Stanford University; Explore Energy Managing Director, Precourt Institute for Energy
Recorded on: May 26, 2023   Duration: 37 minutes

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