What is Ocean Thermal?
Ocean Thermal Energy Conversion (OTEC), often called just ‘Ocean Thermal’, is one of the main types of ocean energy: renewable energy derived from the sea. OTEC is a closed-cycle system that uses the temperature difference between warm surface and cold deep ocean waters to generate electricity through a heat engine. This works best in areas where the temperature difference is greater than 20°C - forming the ‘OTEC Zone’ between the 23rd parallel north and 23rd parallel south covering. Around ~40% of the Earth’s surface is in this zone.
However, unlike wave, wind, and tidal solutions, OTEC provides a constant power source.
The challenge
The core OTEC concept (invented in 1881 around the time of the first hydroelectric plants) and technology have repeatedly been proven, and industry experts agree there are no significant technology or engineering challenges left to solve.
Then why isn’t OTEC infrastructure all over the OTEC Zone?
Essentially, it comes down to economies of scale and the ability to balance variable buyer demand and monetize excess energy during low periods. OceanBit’s novel solution makes OTEC economical, efficient, and scalable - unraveling our ocean-centric countries and companies’ reliance on fossil fuel energy sources.
Head to our solutions area to learn about our pioneering Demand Response OTEC (used in OceanBit APAC projects in the Pacific) and power plant data centers. This technology is paving the way for the future of ocean energy.
How does OTEC work?
The warm surface water evaporates liquid ammonia, which expands and spins a turbine to generate electricity. The evaporated ammonia is then condensed back into a liquid using the cold deep-water supply and is recycled continuously through this closed-loop system. This Rankine cycle produces a continuous base load power.
This closed-cycle system was first proposed in 1881 by French physicist Jacques Arsene d’Arsonval, and developed in the 1970s by America and Japan. The energy generation technology is sound - the ocean provides an endless supply. The challenge facing OTEC is how to commercialize this renewable solution to respond to real-time energy changes. This is where OceanBit’s pioneering solution comes in.
Benefits of Ocean Thermal Energy Conversion
Base Load
OTEC operates 24/7 delivering constant power with a capacity factor of ~95%, unlike intermittent renewable sources.
Clean
OTEC is a carbon-free resource that emits zero emissions, greenhouse gases, and pollution during its power generation process.
Renewable
OTEC uses ocean water heated by solar radiation, combining two of our planet’s most important free and renewable natural resources, as its fuel source.
Abundant
An abundant energy source with the potential to provide up to 88,000 TWh per year, meeting global power demands several times over.
Energy Security
It enhances energy security by diversifying the energy mix and reducing dependence on imported fuels or supply chains subject to geopolitical risk.
Cost Effective
Already a cost-competitive option for multiple use cases and locations, continued technological innovation is making it more cost effective.
“Since the ocean comprises around 70% of the earth’s surface, it is a vast receiver and repository of solar energy.
While waves, winds, tides and currents are all forms of ocean renewable energy, which vary with time and season, conversely, an OTEC system permits the generation of constant power 24 hours a day, 365 days a year.
Effectively the tropical ocean is acting as a gigantic thermal battery”