Oceans are the world’s largest untapped source of renewable energy. With today’s pressing need for sustainable energy solutions, the ocean carries deep potential to shape our future.
Innovative startups are at the forefront of this frontier, developing solutions to harness the power of tides and waves as an energy source. Read on to learn about the companies revolutionizing how we can turn ocean water into renewable energy.
The Fundamentals of Ocean Renewable Energy
Ocean energy refers to all forms of renewable energy that originate from the sea. Ocean energy is renewable because no fuel is needed, and clean since no pollution is generated.
There are three main types of ocean renewable energy technology: wave, tidal, and ocean thermal energy conversion. These technologies convert energy from oceanic processes into electricity.
Current Methods of Harnessing Ocean-Based Energy
Wave Energy: This method captures the energy from surface waves. Devices called wave energy converters transform the kinetic energy of waves into electrical energy. The three main types of wave energy converters are attenuators, absorbers and oscillators.
Tidal Energy: This technology produces power using tides caused by the gravitational interaction between the Earth, the sun, and the moon. Tidal turbines harness the natural rise and fall of sea levels and resulting currents to generate power. Tidal turbines are similar to wind turbines and can be placed on the seafloor or float closer to the surface while attached to the ocean bottom.
Ocean Thermal Energy Conversion (OTEC): This process uses the temperature difference between warmer surface water and colder deep water (thermal gradients) to produce electricity. Ocean thermal energy conversion is typically used in tropical regions where this gradient is strongest. With a temperature difference of at least 36°F or 20°C, OTEC systems can power a turbine to produce electricity.
All three of these ocean technologies remain in the test stage of development. While each are promising renewable energy sources, challenges such as production costs, technological limitations and finding suitable locations have limited the expansion of ocean energy.
Startups Focusing on Wave Power
Wave power is constant and dependable. It is more predictable than wind power, and unlike solar power its output increases during the winter when electricity demand is highest. But setup costs are high, and the industry has not reached large-scale commercialization yet.
Several startups are trying to solve the challenges of wave power, and are pioneering advancements in the technology:
CalWave
CalWave is a clean tech startup based out of California focused on reliable, cost-effective ocean wave technologies. The company has developed the xWave wave energy converter, a fully autonomous and submerged device that captures energy from ocean waves while remaining protected from swells and storms. In 2022, CalWave completed a successful open-ocean pilot off the coast of San Diego, during which time the xWave buoy survived two extreme storms and required no interventions.
AW-Energy
Founded in 2002 in Finland, AW-Energy is developing a wave power plant based on a submerged panel that oscillates with the movement of waves in near-shore areas. The WaveRoller wave energy converter is a submerged steel panel that captures the kinetic energy of seabed waves. Because the WaveRoller is positioned near the shore, it is easy to access the device.
Since 2019, AW-Energy has conducted successful pilot projects in Portugal and in 2024 secured approval for an ocean energy pilot project in Nambia.
CorPower Ocean
CorPower Ocean has developed compact wave energy converters with technology inspired by the pumping principles of the human heart. The Swedish company’s buoys absorb energy from ocean waves, then generators inside convert that energy into electricity. The light-weight technology aims to deliver five times more energy per ton of device compared to other wave energy technologies.
In October 2024, CorPower secured €32 million in funding to commercialize its technology, after successfully testing a commercial-scale product in northern Portugal.
Startups Exploring Beyond Traditional Ocean Energy Sources
Beyond wave, tidal and thermal energy, innovative startups are exploring alternative ocean-based energy sources:
Sweetch Energy
Sweetch Energy, a VivaTech alumni, is a French climate tech startup specializing in osmotic energy (also called salinity gradient energy) – a renewable power source generated by the natural process of osmosis when freshwater and seawater mix.
The company’s core innovation is its Ionic Nano Osmotic Diffusion (INOD) technology, which leverages breakthroughs in nanotechnology to efficiently and sustainably convert osmotic energy into electricity. Sweetch Energy will put its zero-carbon electricity generation technology to the test at its first osmotic demonstrator plant in Port-Saint-Louis-du-Rhône, France at the mouth of the Rhône River.
SolarDuck
Dutch-Norwegian startup SolarDuck is developing offshore floating solar power plants that can sustain the harsh ocean conditions. This technology allows vast ocean surfaces to be used for solar energy capture, instead of land in highly populated areas that could otherwise be used for housing or food production.
Floating offshore solar can also deliver more energy than onshore farms because of lower temperatures at sea and the use of bifacial solar panels that can capture both direct and reflected sunlight. SolarDuck has deployed a pilot program in the Dutch North Sea and aims to have the biggest offshore floating solar plant in the world operational in 2026.
The future of ocean energy is still evolving, with several emerging technologies on the horizon. But the ocean holds vast potential as a renewable energy source and startups across the world are working to unlock this potential. As these technologies mature, they promise to play a significant role in the world’s transition to sustainable energy.
