otec
CHAPTER 1
Introduction
Covering over 70% of the planet’s area, the Earth’s oceans could potentially be utilized as a source of virtually inexhaustible renewable energy. Ocean Thermal Energy Conversion (OTEC) is a method that employs naturally occurring temperature differences between warm surface water and colder deep seawater. To be effective a minimum temperature difference between the ocean surface layers is 20C . These temperature gradients exist primarily in specific tropical regions near the equator originally proposed by French Engineer Jacques Arsene d’Arsonval in 1881, OTEC is not a new technology. Since then many advancements have been made in the development of this technology. The three most common OTEC systems are: open-cycle, closed-cycle and hybrid cycle, all requiring a working fluid, condenser and evaporator within the system. These three systems all employ the thermodynamics of a working heat exchanger and use the temperature differences naturally occurring in the ocean as the driving force. Concerns with efficiency losses due to befouling, system power requirements and heat exchanging systems have lead to exploration through case studies and analysis. While OTEC systems have been studied since 1881 there have been few full-scale implementations. There are still, however, a number of studies being conducted, especially in Japan, regarding the implementation of this renewable large scale technology.
CHAPTER 2
Plant design and location
The location of a commercial OTEC plant has to be in an environment that is stable enough for an efficient system operation. The temperature differential at the site has to be at least 20C(680F). Generally the natural ocean thermal gradient necessary for OTEC operation is found between latitudes 20 north and 20south. Land-based OTEC plants do not require a sophisticated mooring system, lengthy power cables and more extensive maintenance as required with open ocean environment.
Introduction
Covering over 70% of the planet’s area, the Earth’s oceans could potentially be utilized as a source of virtually inexhaustible renewable energy. Ocean Thermal Energy Conversion (OTEC) is a method that employs naturally occurring temperature differences between warm surface water and colder deep seawater. To be effective a minimum temperature difference between the ocean surface layers is 20C . These temperature gradients exist primarily in specific tropical regions near the equator originally proposed by French Engineer Jacques Arsene d’Arsonval in 1881, OTEC is not a new technology. Since then many advancements have been made in the development of this technology. The three most common OTEC systems are: open-cycle, closed-cycle and hybrid cycle, all requiring a working fluid, condenser and evaporator within the system. These three systems all employ the thermodynamics of a working heat exchanger and use the temperature differences naturally occurring in the ocean as the driving force. Concerns with efficiency losses due to befouling, system power requirements and heat exchanging systems have lead to exploration through case studies and analysis. While OTEC systems have been studied since 1881 there have been few full-scale implementations. There are still, however, a number of studies being conducted, especially in Japan, regarding the implementation of this renewable large scale technology.
CHAPTER 2
Plant design and location
The location of a commercial OTEC plant has to be in an environment that is stable enough for an efficient system operation. The temperature differential at the site has to be at least 20C(680F). Generally the natural ocean thermal gradient necessary for OTEC operation is found between latitudes 20 north and 20south. Land-based OTEC plants do not require a sophisticated mooring system, lengthy power cables and more extensive maintenance as required with open ocean environment.