The oceans are the largest solar collectors on Earth providing an abundant and sustainable energy source. They capture a large part of the sunlight that falls on Earth, warming the ocean’s surface layer. The deep layer remains cold, which creates the ocean’s naturally available temperature gradient, or thermal energy. Utilizing the ocean’s thermal energy enables a multitude of products and systems, such as cooling by means of seawater air-conditioning (SWAC), electricity by means of Ocean Thermal Energy Conversion (OTEC), and systems for the production of fresh water, agriculture and aquaculture.
Ocean Thermal Energy Conversion (OTEC)
Ocean Thermal Energy Conversion is a technology for generating electricity by using the temperature difference between the warm surface water and the cold deep water in the ocean. The warm surface water is used to evaporate a so-called working fluid, comparable to the fluid used in a fridge. The vapor drives an electricity generating turbine. The cold water brought up from the deeper ocean layer is then used to condense the vapor so it can be reused. A cycle is therefore created, one that generates electricity.
OTEC is possible where a temperature difference in the ocean greater than 20°C. This temperature gradient is readily found in most tropical regions with access to deep seawater near the coast. These and more local conditions shall be considered in assessing each location’s potential for OTEC implementation.
Seawater Air Conditioning (SWAC)
Seawater Air-Conditioning is using the cold deep seawater at 4°-8°C directly for cooling. The cold seawater is circulated through heat exchangers and replaces energy intensive chillers or cooling units, which allows for up to 90% energy savings.Seawater Air Conditioning relies on the deployment of a deep seawater pipe to carry the necessary water to the surface. Local conditions such seabed profiles and ocean temperature gradients are important factors in determining the economic return of the project.
Ocean Ecoparks utilize the ocean resource to its highest potential, hosting and incubating various tenants that lease individual pieces of land to deploy their specific application. The Ocean Ecopark supplies the tenants with warm and cold, nutrient rich seawater that they can use for their specific application. Tenants could be aquaculture companies, drink-water producers, algae biofuel producers, academic and commercial R&D facilities, etcetera. Ecoparks are tailored and designed to meet specific location’s needs and provide a setting conducive to innovation and economic growth.