41 research outputs found
Ocean Thermal Energy Conversion: The Codification of a Potential Technology
Rapid technological advancement has been the hallmark of post-industrial societies for more than a quarter of a century. This progress is forever disrupting our established legal systems. Nowhere is this tension more evident than in the discoveries of the developing energy industry. An exception to this process is the infant industry of ocean thermal energy conversion (OTEC). The United States Congress recently enacted legislation establishing the legal framework for the OTEC process, which has not yet been proven on a commercial scale.
OTEC is a form of solar energy that takes advantage of the vertical temperature differentials in those regions of the ocean generally between twenty degrees North latitude and twenty degrees South latitude. An OTEC system consists of a power plant, a floating platforms to house the plant, a surface-level seawater system, a deep water seawater system, and a method of transmitting or utilizing the energy produced. Warm surface water is pumped into a heat exchanger to vaporize a working fluid. A turbo-generator converts the resulting vapor\u27s thermal energy into mechanical and then electrical energy. The vapor leaving the turbine flows into a condenser where it is cooled by cold water pumped up from the deep ocean through a long pipe descending as much as 700 meters or deeper.
Although commercial facilities are not expected to be available prior to the late 1980\u27s, two types of OTEC systems are presently under consideration. The closed cycle system6 is closer to commercial realization. In this system, heat derived from surface waters evaporates a working fluid such as ammonia and forces the resulting vapor through a turbine. The turbine powers a generator to create electricity. The vapor returns to liquid form after being chilled with cold water from the ocean depths. The second system is the open cycle system. In this process, warm surface seawater is evaporated in a vacuum. The resulting steam powers a turbine and is then condensed with cold seawater drawn from the ocean depths.
OTEC has the potential to fulfill the energy needs of oil-dependent communities. Because OTEC\u27s energy source is solar, it is renewable. Unlike other solar technologies, however, OTEC can operate twenty-four hours a day, year-round due to the ocean\u27s immense solar-collection properties. Yet OTEC will be used for much more than electrical power generation. It has the potential for ammonia production, which presently requires nearly three percent of the total United States output of natural gas. OTEC can be used to process and refine minerals and produce other energy-intensive products such as aluminum. OTEC power can be used to produce fuel for fuel cells that can be transported and used for electricity elsewhere. Considering all these potential uses, OTEC will be a promising area of renewable energy technology if it evolves in a cost-effective and environmentally acceptable manner
The Legal Framework for the Development of Ocean Thermal Energy Conversion (OTEC)
This Article analyzes the legal framework envisioned in recent legislation that was created to encourage the development of Ocean Thermal Energy Conversion (OTEC) as a commercial energy technology and suggests various changes to the statutory framework. The author highlights the implications of the ongoing United Nations Law of the Sea Negotiations for OTEC development. The author concludes that, while uncertainties remain, the legislation marks a significant step toward the eventual development of OTEC as a viable energy source
Recommended from our members
Ammonia Production from a Non-Grid Connected Floating Offshore Wind-Farm: A System-Level Techno-Economic Review
According to U.S. Department of Energy, offshore wind energy has the potential to generate 7,200 TWh of energy annually, which is nearly twice the current annual energy consumption in the United States. With technical advances in the offshore wind industry, particularly in the floating platforms, windfarms are pushing further into the ocean. This creates new engineering challenges for transmission of energy from offshore site to onshore. One possible solution is to convert the energy produced into chemical energy of ammonia, which was investigated by Dr. Eric Morgan. In his doctoral dissertation, he assessed the technical requirements and economics of a 300 tons/day capacity ammonia plant powered by offshore wind. However, in his dissertation, one of the assumptions was connection to the grid which provided auxiliary power to keep the ammonia plant operational and produce at rated capacity. It also allowed selling of excess power to the grid in the scenario of excess power production by wind farm during high winds.
This thesis explores the technical and economical feasibility of a similar system, except that the ammonia plant will be on a plantship and there is no connection to the grid. This creates a challenge as the ammonia synthesis plant must operate between 65-100% loads. Thus, the concept of multiple mini-ammonia plants is used to address the scenario of wind energy production at less than rated power. This will allow operation of one or more mini-ammonia plant (corresponding to the available energy from offshore wind). In the event of wind speed lower than the cutoff wind speed for the turbine, the ammonia plant will use the produced ammonia as fuel, with the help of a gas turbine running on either Brayton cycle or combined cycle, to keep the plant idling. It will maintain the reaction conditions of the synthesis chamber and will not produce any ammonia. This is an important step as it takes days to reach the reaction conditions to start ammonia production again after shutting down due to unavailability of energy at low winds. Thus, at any windspeed, a mini-ammonia plant would either idle or operate between 65-100% load. This model will be used to simulate the total energy consumption, total energy captured by the wind farm, and the total ammonia produced. This will further help in assessing the final cost of producing, transporting, and consuming ammonia as fuel and thereby provide a better understanding of the feasibility of implementing this technology.
According to U.S. Department of Energy, offshore wind energy has the potential to generate 7,200 TWh of energy annually, which is nearly twice the current annual energy consumption in the United States. With technical advances in the offshore wind industry, particularly in the floating platforms, windfarms are pushing further into the ocean. This creates new engineering challenges for transmission of energy from offshore site to onshore. One possible solution is to convert the energy produced into chemical energy of ammonia, which was investigated by Dr. Eric Morgan. In his doctoral dissertation, he assessed the technical requirements and economics of a 300 tons/day capacity ammonia plant powered by offshore wind. However, in his dissertation, one of the assumptions was connection to the grid which provided auxiliary power to keep the ammonia plant operational and produce at rated capacity. It also allowed selling of excess power to the grid in the scenario of excess power production by wind farm during high winds.\\ \par This thesis explores the technical and economical feasibility of a similar system, except that the ammonia plant will be on a plantship and there is no connection to the grid. This creates a challenge as the ammonia synthesis plant must operate between 65-100\% loads. Thus, the concept of multiple mini-ammonia plants is used to address the scenario of wind energy production at less than rated power. This will allow operation of one or more mini-ammonia plant (corresponding to the available energy from offshore wind). In the event of wind speed lower than the cutoff wind speed for the turbine, the ammonia plant will use the produced ammonia as fuel, with the help of a gas turbine running on either Brayton cycle or combined cycle, to keep the plant idling. It will maintain the reaction conditions of the synthesis chamber and will not produce any ammonia. This is an important step as it takes days to reach the reaction conditions to start ammonia production again after shutting down due to unavailability of energy at low winds. Thus, at any windspeed, a mini-ammonia plant would either idle or operate between 65-100\% load. This model will be used to simulate the total energy consumption, total energy captured by the wind farm, and the total ammonia produced. This will further help in assessing the final cost of producing, transporting, and consuming ammonia as fuel and thereby provide a better understanding of the feasibility of implementing this technology