FAU: Ocean power options viable for Florida soon- pilots in process

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Florida Atlantic University
Center of Excellence in Ocean Energy Technology

Why ocean energy?
Florida’s cleanest, most energy dense and abundant base load-capable source of renewable energy is its oceans. The Gulf Stream Current flows northward past the southern and eastern shores of Florida, funneling through the Florida Straits with a mass transport greater than 30 times the total freshwater river flows of the world. The steady currents of the Gulf Stream, in addition to those found in other regions of the world, are highly energetic, and carry with them enormous potential for electric power generation. The ocean flow of the Gulf Stream is more than five times as energy-dense as the world’s best wind power-generating sites. The ocean current energy resource of Florida has a potential generating capacity in excess of 10 GW, equal to some 10 nuclear power plants. This flow creates the potential for base load, summer-peaking energy generation with an annual average power density of 1.95 kW/m2, and an average summer power density of 2.52 kW/m2.
The warm surface water of the Gulf Stream overlays colder water flowing into the Florida Straits from Arctic regions through the deep ocean which causes a temperature difference that exceeds 22 ºC with the deep ocean water averaging 4 ºC, yielding an energy difference of over 100 MW/m3 of seawater. Florida is the only place in the continental U.S. with these optimal conditions. Not only can the temperature difference be used to directly create electricity using Ocean Thermal Energy Conversion (OTEC) technology, but also cold water can be used in heat exchangers for air conditioning (up to 45 percent of Florida’s residential electricity consumption is used for air conditioning). The cold water can also be used to generate fresh water for aquaculture, to cool thermal effluent from existing power plants, and to mitigate freshwater discharge into coastal estuaries.
Ocean energy can be a major contributor to Florida’s energy portfolio, and can help provide independence through sustainable, reliable, renewable, and clean energy. Ocean energy can also create a new economic sector including associated industries, boasting a potential to create tens of thousands of jobs and billions of dollars of revenue.
The ocean is a source of two significant sustainable forms of energy: thermal energy associated with the thermal gradients in the ocean (generated by the sun’s heats absorbed by the ocean), and mechanical energy associated with the waves, currents, and tides. Since the oceans cover over 71 percent of the earth’s surface, they represent the largest solar collectors and retainers of the sun’s vast energy that reaches the earth’s surface – an estimated 10,000,000 Gigawatts (GW). The oceans effectively convert solar radiation into ocean thermal, current, and wave energy. Just a small fraction of the ocean’s energy could power the world. The technology developed in Florida can thus yield a reliable and renewable source of energy that can be used to generate electricity directly. Ocean energy can establish Florida as the clear leader in key emerging technologies for harnessing ocean energy, with a potential to dwarf the world’s oil and coal sectors. With this limitless international development potential, ocean energy can profoundly change Florida’s economy and generate a sector with hundreds of thousands of jobs around the world, many based in Florida. Florida is arguably the best location on the planet to pursue ocean harvesting technology development and commercialization because of its close proximity to the Gulf Stream, a large ocean thermal source, and a deep cold-water source.

Summary – Why Ocean Energy
• Base load clean renewable energy
• The Florida current has the kinetic energy of a sustained 100 mph wind
• Massive potential for power, potable water, and hydrogen generation
• Cold water cooling systems can be used to reduce energy consumption
• Seasonal energy potential matches demand
• Florida is the best location on earth to harness Ocean Current Energy
• Florida can lead the world in ocean renewable energy
• Enormous economic potential
• Little surface structure
• Potential to eliminate shore based power plants
• Very little land usage

Is it close to commercialization?
The kinetic energy of the Gulf Stream and all of the other ocean currents lies in the momentum (velocity) of the fluid over the ground. This is identical to kinetic wind energy, but water is more than 700 times denser than air. Thus, ocean current energy can be harnessed in much the same way as energy is harnessed from wind. For example, ocean currents can create lift forces on rotor blades that generate a torque that turns a gearbox and attached generator producing electricity. Since wind energy technology is significantly advanced, it can be leveraged to provide the basis of many ocean energy-harvesting systems. Presently, wind turbine systems have advanced so that the generation systems can be directly used for ocean current energy. The challenge lies in designing systems that can operate in seawater (often in, or above, very deep water) and efficiently generate electricity from high-torque and low-RPM systems (wind generators are typically driven by low-torque and high-RPM systems). With sufficient funding, commercial turbines could be realized in as little as three years. Presently, Florida Atlantic University (FAU) plans to deploy a small test turbine in the Gulf Stream in fall 2007 – permitting dependant.
Ocean thermal energy, the energy potential contained in the temperature gradients in the ocean, is by far the most abundant form of renewable energy on the planet. Ocean thermal energy is derived from the heating of the ocean surface in the tropical seas and the cooling of the ocean water at higher latitudes. The denser colder water sinks and flows throughout the ocean basins until it is below the warm tropical water. The absorption of the solar energy in the tropics heats the surface water and this heating is the energy source. Since the tropical seas cover an estimated 60 million square kilometers, on a typical day, these waters absorb an amount of solar radiation that has the energy content of about 250 billion barrels of oil. The world’s energy could be supplied if less than 0.02 percent of the absorbed energy is harvested . Offshore Florida, the Gulf Stream pumps a continuous flow of warm water from the Caribbean that flows over cold bottom water. This provides a year round energy source for Florida.
Although OTEC research is not a new area, and there has been a few small OTEC plant operating, much of the work is decades old (conversion efficiencies are only between 1-5 percent) and significant investments in technology development have not been made in more than two decades (in comparison, solar energy research has been continuous and funding levels exceed $10+ billion dollars). Recent advances in materials, thermal power generators, and energy storage, coupled with the enormous energy potential of ocean thermal energy, make ocean thermal energy research a very attractive and promising path. With sufficient investment an ocean thermal plant could be commercially viable in as little as 7 – 10 years.
Along Florida’s South and East coasts, “artificial upwelling” creates a significant potential to reduce electricity usage by providing communities cold water based cooling because deep cold water exists close to shore (Florida’s South and East coastlines are located at the closest approach of the continental shelf - deep water – in the continental U.S.) The concept is: to pump cold, deep, offshore water up to shore through large diameter pipes. The water would then pass through heat exchangers that cool air is forced through. The heat exchanger cools that air and provides a source of cold (approximately 40 Fahrenheit) air to cool shore-side structures. Not only can the cold water be used for cooling, it holds an important potential for sustaining aquaculture, fresh water generation, energy generation enhancement, and environmental mitigation. Presently, cold water based cooling is being used on a few pacific islands and the technology is already commercial, but research and development is needed on large-scale facilities that would be needed for areas such as Florida.

Could ocean energy be ready by 2020?
Certainly. Ocean energy is undeveloped when compared with other conventional and renewable energy technologies, such as wind, hydro, and solar. At this point, no commercial ocean energy harvesting systems exist. However, with investment and in technology development, base load ocean energy harvesting systems could easily be a reality by 2020. Reasonable timelines for commercial scale technologies are:
• Ocean current energy: 2010 – 2014
• Cold water based air conditioning: 2010 – 2015
• Ocean thermal potable water generation: 2012 - 2015
• Ocean thermal energy: 2015 – 2020

Should it be included in the Renewable Portfolio Standard?
Absolutely. Ocean energy has the unique potential in Florida to not only change Florida’s energy portfolio in a significant and meaningful way by adding base load clean renewable energy capacity measured in gigawatts at locations where it is needed, but it also has the potential for significant Florida-wide economic impact – Florida is surrounded by the ocean on three sides. Florida has the longest coastline of all 48 contiguous states, with nearly 1400 miles of general coastline, and almost 8500 of tidal shoreline . With most of Florida’s population living within 15 miles of shore, the oceans represent a significant source of renewable energy. Thus, in conjunction with the other renewable energies relevant for Florida, ocean energy can provide the backbone for energy independence. Therefore, ocean energy should be included in the Renewable Portfolio Standard. Based on the energy potential of the oceans surrounding Florida, the Florida Center of Excellence in Ocean Energy Technology has estimated that ocean energy can help nearly eliminate Florida’s dependence on oil. Below is an optimistic graph showing the potential by 2025. Although the graphic portrays a best-case scenario, it demonstrates the potential of ocean energy.


Vision of the Center of Excellence in Ocean Energy Technology at Florida Atlantic University

The Florida Center of Excellence in Ocean Energy Technology (FCOEOET) is a partnership between academia, industry, and government that establishes a nucleus of core capabilities that are needed to propel the research, development, and commercialization of viable ocean energy technologies. The unifying role of the FCOEOET bridges concept and commercial implementation through a broad range of unique, enabling, and accessible expertise and physical assets. The FCOEOET expertise includes ocean engineering, material science, marine biology, physical oceanography, hydrogen engineering, environmental, ocean operation, and policy. The Center shall also possess and operate a wide range of assets, including a (soon to be installed) permanent offshore instrumented testing and evaluation range, research vessels, laboratories, and fabrication facilities.
Scientific, research, and engineering efforts shall discover, investigate, and refine enabling technologies. This effort will yield affordable technology development, and creation of viable new energy technologies and products. Focus areas are: 1) ocean current energy systems, 2) ocean thermal energy systems, 3) cold deep ocean water-based air-conditioning, 4) underwater hydrogen generation and storage 5) fresh water generation using ocean thermal gradients, and 6) environmental impact and mitigation. Utilizing Florida Atlantic University’s established technology transfer program, and working with industrial partners, resulting technology and products will be transferred to establish and maintain a seed industry, thereby establishing and growing a Florida-based ocean energy industry. Simultaneously, a strong academic environment and substantial hands-on testing resources provide the backbone to develop the workforce necessary to establish and grow an ocean energy industry. In addition to technical and educational endeavors, the Center is a unique set of expertise with unparalleled knowledge of the Florida oceans. As such, the Center shall work with federal, state, and local government to develop responsible policy and rule.

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1. FAU Ocean Power Project URL

Florida Center of Excellence in Ocean Energy Technology
Department of Ocean Engineering

http://coet.fau.edu/?p=oceanres