According to the National Renewable Energy Laboratory,1 60 million square kilometers (23 million square miles) of tropical oceans daily absorb solar radiation equal in heat content to about 250 billion barrels of oil (e.g., 1,450 Quads). This is an order of magnitude greater than the expected total U.S. energy consumption through 2030, and twice the projected global energy demand. Even using present maximum estimates for steady-state sustainable energy harvesting2 (e.g., 3 to 5 TW, or 90 to 150 Quads), this resource still provides enough clean and non-GHG emitting energy to supply 15 to 20 percent of the global energy demand in 2030.
Ocean thermal energy conversion (OTEC) technologies convert the solar radiation that heats the surface of the ocean into electrical power by exploiting the thermal gradient temperature differences between the surface and the depths. This temperature gradient in the Tropics (see Figure 1) can be 20 degrees C (36 degrees F) or more between the warm surface water and the cold deep seawater, which is sufficient to produce usable power, albeit not very thermodynamically efficiently (i.e., 3 to 5 percent). It should be noted that lying within the Tropical zone——the area most favorable for OTEC—are some 29 territories and 66 developing nations, as well as portions of Australia and Hawaii, all of which are natural markets for OTEC-generated energy and other side-products.
This enormous resource merits a closer look as policy makers consider alternative technologies for serving future energy demands. Achieving viability, however, will require more supportive and stable regulatory policies as well as funding for research and development.
The science behind OTEC was first described in 1881, when a French physicist, Jacques Arsene d’Arsonval, proposed using what came to be known as a closed-cycle plant to tap the thermal energy of the ocean;3 however, it took almost 50 years for the concept to be applied. In 1930, Georges Claude, a student of d’Arsonval, built the first open-cycle OTEC plant in Matanzas Bay, Cuba, which produced 22 kilowatts (kW) of electricity before being destroy-ed by inclement weather and waves. Undeterred, Claude constructed another open-cycle plant aboard a 10,000-ton cargo vessel moored off the coast of Brazil in 1935; however, it too was destroyed by weather and waves before he could produce net power.4 Twenty-one years later, another French team attempted to build a 3-MW open-cycle (Claude-cycle) plant for Abidjan, then the capital of Côte d’Ivoire; however, the plant never was completed because it couldn’t compete economically with local fossil-fueled power plants.
Mini-OTEC, the world’s first net-power-producing floating OTEC plant, and part of the first foray by the United States into this technology, was deployed in 1979 on a barge at Keahole Point on the Kona coast of the island of Hawaii. This proof-of-concept demonstration facility was developed by the Natural Energy Laboratory of Hawaii (NELHA) and several private firms, including Lockheed Ocean Systems. It operated for three months, generating approximately 50 kW of gross power with net power ranging from 10 to 17 kW.5 Based on the results of Mini-OTEC, it was estimated that a 10-MW OTEC facility could achieve net-to-gross power production efficiency upwards of 75 percent, which would make it more commercially viable than the Mini-OTEC unit. Moreover, OTEC appears to be directly scalable with the applicable economies-of-scale that it implies; that is, the larger the OTEC plant, the more energy can be harvested, and the more cost-effective it is.
The results were so favorable that, in 1980, the U.S. Department of Energy (DOE) built OTEC-1, a non-power test-bed, on a converted U.S. Navy tanker to identify methods for designing commercial-scale heat exchangers, and demonstrated that OTEC systems can operate from slowly moving ships with marginal impact on the marine environment. This facility wasn’t designed to produce electricity, but rather to certify necessary technologies. DOE spent approximately $260 million on OTEC research and development between 1975 and 1982.6
The U.S. Congress, in order to support and promote the commercial development and deployment of the nascent OTEC industry, passed Public Law (PL) 96-320, the Ocean Thermal Energy Conversion Act of 1980, as amended by PL 98-623, National Fishing Enhancement Act of 1984, to, among other actions, “...establish a legal regime which will permit and encourage the development of ocean thermal energy conversion as a commercial energy technology” [42 USC 9101(a)(4)]. The U.S. Congress also enacted the Ocean Thermal Energy Conversion Research, Development, and Demonstration Act, PL 96-310, which stated that “it is in the national interest to accelerate efforts to commercialize ocean thermal energy conversion by building pilot and demonstration facilities and to begin planning for the commercial demonstration of ocean thermal energy conversion technology” [42 USC 9100(a)(5)]. PL 96-310 established “as a national goal ten thousand megawatts [10,000 MWe] of electrical capacity or energy product equivalent from ocean thermal energy conversion systems by the year 1999” [42 USC 9100(b)(4)].
However, following the Mini-OTEC testing, next-generation energy costs world-wide plummeted, and continued OTEC research no longer was economically justifiable. In the 1990s, while some domestic companies and NELHA performed testing on complimentary technologies, most of the research and development work was supported by such countries as Japan and India. For in-stance, in 1981, Japan demonstrated a land-based, 100-kW closed-cycle power plant on the island Nation of Nauru, which exceeded engineering expectations by producing 31.5 kW of net electric power during continuous operating tests. Testing of an open-cycle OTEC plant at NELHA in 1993 produced 50 kW during a net power-producing experiment. In 1996, Japan’s Saga University entered into an agreement with the National Institute of Ocean Technology of India to collaborate on the design and construction of a 1 MW plant to be located off the coast of Tamil Nadu in India. The facility, built in 2002 with Xenesys Inc., was unsuccessful due to a failure of the deep sea cold water pipe and has since been decommissioned.
Renewed interest in OTEC occurred in the second half of the first decade of the 21st century when fossil-fuel prices began to climb, and concerns were raised about the environmental impacts of continued usage of these carbon-based fuels, as well as energy-related security issues. Further, the necessary component technologies that go into developing a viable OTEC infrastructure has benefitted from complimentary research and development efforts undertaken in the past several decades for other purposes.
As a part of comprehensive energy legislation Congress passed in 2007, the Marine and Hydrokinetic Renewable Energy Research and Development Act was enacted. This law created a DOE program to support renewed research into OTEC (as well as tidal, wave and other marine or hydrokinetic energy technologies), and authorized spending $50 million a year through 2012 for technology R&D, as well as grants to universities to establish marine energy R&D centers.8 Management of this program is within the DOE office that also oversees wind and hydropower. Congress provided $10 million for “Water Power R&D” in Fiscal Year (FY) 2008 and another $40 million for FY 2009,9 which enabled the DOE to fund grants under this program. In September 2008, DOE announced the first grants, totaling up to $7.3 million, released under this program, and which included two grants related to OTEC. Up to $.6 million for a possible 2 years was awarded to Lockheed Martin to “validate manufacturing techniques for coldwater pipes critical to OTEC in order to help create a more cost-effective OTEC system,” and another $1.25 million for as many as 5 years to the University of Hawaii to establish the National Renewable Marine Energy Center, which in part will “assist the private sector in moving ocean thermal energy conversion systems beyond proof-of-concept to pre-commercialization, long-term testing.”10 Furthermore, funding committed to other ocean-energy research may have cross-pollination opportunities with OTEC, particularly as it relates to controlling corrosion, mitigating damage from ocean forces, and developing high-voltage undersea electrical cables. Finally, funding has been made available by Congress for OTEC research in recent Defense Department spending bills.11
Unfortunately, federal support for renewable R&D has been highly vola-tile, and in the context of the energy market, very low.12 As UC Berkeley Professor Dan Kammen wrote, “Many R&D programs have exhibited roller-coaster funding cycles, at times doing more harm than good to the sustainable development and deployment of specific technologies.”13
While President Obama and his administration have indicated their intent to increase federal support for renewable research, as reflected in the significant amount of funding made available in the economic stimulus and recovery law passed in early 2009, sustaining these amounts is important to send signals to private and institutional researchers that their pursuits of OTEC research will continue being funded. Despite the need for expanded R&D funding, the existing authorizing laws, grant programs and university-based research centers will help lay the institutional foundation for not only developing this technology, but also for growing the knowledge and workforce capacity necessary for long-term domestic development of OTEC.
With the above caveats, the time appears ripe for revisiting the development and deployment of commercial OTEC plants.
There are three types of OTEC plants: closed-cycle, open-cycle, and hybrid-cycle. The main differences between the first two is that the closed cycle uses the warm surface waters to heat a low-boiling point fluid, such as ammonia, that is used to drive the turbine-generator, while the open cycle utilizes a vacuum to flash sea water to steam, which then is used to turn the turbine-generator. The hybrid cycle uses features of both the closed- and open-cycles.
In d’Arsonval’s closed-cycle OTEC system (see Figure 3), the warm surface water is sent through a heat exchanger (evaporator) where the low-boiling point working fluid is vaporized. This vapor is used to turn the turbine-generator, generating electricity. The vapor is then sent to a condenser where the cold sea water from the depths removes the remaining heat, which condenses it back to liquid. A pump sends the fluid back to the heat exchanger, completing the closed loop, and ensuring that the working fluid that remains continuously is circulated in a closed system, achieving relatively high efficiencies at a smaller scale when compared to the open-cycle system. This is essentially the same technology as is used in standard refrigeration systems, and the technology is well-understood and fairly mature, allowing for a straightforward scale-up to commercial sizes.
For the open-cycle system pioneered by Claude (see Figure 4), the warm surface sea water is pumped into a low-pressure (vacuum) flash evaporator, causing it to boil into desalinated water vapor. This low-quality steam drives a low-pressure turbine-generator, and then is condensed into potable water in the condensor. This system allows for not only the generation of electricity, but also fresh water. In 1984, the Solar Energy Research Institute (now the National Renewable Energy Laboratory, NREL) developed an evaporator for open-cycle plants that had conversion efficiencies as high as 97 percent.
The hybrid OTEC system combines the features of both the closed- and open-cycle systems (see Figure 5). Similar to the open-cycle process, warm sea water is flash-evaporated into steam in a vacuum chamber; however, this steam then is used to vaporize a low-boiling-point fluid, like the closed-cycle system, which then drives a turbine to produce electricity. The major advantage to the hybrid system is that is considered a more efficient producer of both electricity and side products like desalinated water.
OTEC facilities can be built on: 1) land or near the shore; 2) deep-water platforms moored to the continental shelf within a nation’s Exclusive Economic Zone (EEZ); or 3) free-floating facilities in deep ocean water (either within or beyond the EEZ). In determining the site selection of OTEC facilities, there are three technical considerations—thermal gradient, sea water depth, and offshore distance, which impacts efficiency of electrical and other side-product transmissions—and the territorial sovereignty that applies to adjacent waters. In a nation’s inland and territorial waters, rights of regulatory competence and judicial oversight are unquestioned. This right assumes less prominence as the off-shore distance increases until, eventually, national sovereignty disappears completely and the law of the high seas takes hold. OTEC site selection will be governed by the political and legal realities of operating outside territorial waters. If desirable near-shore sites don’t present favorable thermal conditions, OTEC operators will be compelled to locate in international waters. In OTEC markets, this calculation is particularly acute for land-locked nations, and states bordered by colder waters in the temperate north and south.
The main advantages that land-based and near-shore facilities offer are that they don’t require sophisticated mooring or lengthy power cables and side-product piping, and they offer ease of access. However, there will be additional expenses involved in the extended warm- and cold-water piping infrastructure (which are exposed to additional stresses of the shallow water environment). This siting allows for the smallest scaleof operations (hence, less cost-effective). There is the potential for local environmental issues not seen by the other two siting choices. And in order to minimize pump head losses, the heat exchangers will need to be located below sea level, thus requiring additional site expenses.
Like the state-of-the-art construction techniques used in the present-day offshore industry in building and siting deep-water oil platforms, deep-water and open-sea OTEC plants easily can be built in a shipyard, towed to the site, and—for moored deep-water platforms—fixed to the sea bottom away from shore (either by pilings or cables), thus avoiding the negative effects of the surf zone and coming closer to cold waters. Among the other advantages of the deep-water moored OTEC plants are that they have easy access to sea-water resources and can have larger scale of operations, making them more cost-effective. However, among the challenges that they face are the need for sophisticated mooring cabling systems; increased lengths of power cables and side-product piping; and the impacts of open-ocean storm conditions.
Free-floating OTEC facilities could be preferable if the plant isn’t intended to deliver electricity to shore, but is designed for production of other side-products (e.g., fresh water, liquid fuels and mineral extraction). The advantages the free-floating OTEC plant offers include siting in areas not subject to hurricanes; largest scale of operations; and no mooring or stabilization issues. However, free-floating facilities present the difficulty of having to ship the side-products to shore, although the shipping distances would be considerably shorter than those already accomplished by the oil industry.
Besides providing a source of clean, renewable baseload electrical energy, OTEC has the potential to provide many useful side-products such as desalinated fresh water for industrial, agricultural, and residential uses; liquid fuels (e.g., hydrogen, ammonia, and biofuels); foods from mariculture and greenhouses (including cold-weather crops utilizing chilled-soil agriculture to provide the right growing conditions); resource extraction from the brine (i.e., lithium, molybdenum and uranium may be profitably extracted from seawater considering the flow rates needed to operate the OTEC plant); and, if close enough to shore, provide moderate-temperature refrigeration and air-conditioning for buildings or for on-board facilities. In addition, utilizing the “Energy Island” concept14 developed by Dominic Michaelis, the OTEC plant could incorporate other renewable energy-gathering technologies (e.g., wind, photovoltaics, concentrating solar, wave, current, and reverse-pumped energy storage (PES) to increase the overall energy production capabilities. Finally, the OTEC plant could be co-located with other industrial facilities (e.g., computer server farms, cargo transhipment facilities, shipping refueling facilities), in order to provide additional revenue streams.
While there are challenges to bringing OTEC to commercial viability, building this energy infrastructure would offer many advantages.
First, they provide clean, renewable, and independent baseload energy production. Unlike other sources of renewable energy that vary depending on weather and time of day, OTEC power plants can produce electricity 24 hours a day, 365 days a year,15 providing customers with enough power and water to make them independent of costly fuel imports. OTEC has a virtually non-existent carbon footprint, which leads to little if any adverse environmental impacts, particularly when compared with other energy sources. Since OTEC isn’t exothermic (like fossil-fueled and nuclear power plants), and since the cold or mixed water will be discharged at depth, it doesn’t contribute directly to global warming.
Second, it can produce fresh water for various purposes. Both open-cycle and hybrid plants directly can produce potable water as well as electricity (at a rate of about 700,000 gallons/MW) that is suitable for human consumption, as well as agriculture and livestock needs, which can be significant for areas that have little rainfall or increasing fresh water needs.16, 17
OTEC plants can produce fuels in addition to heat and electricity. OTEC plants can produce hydrogen (through electrolysis of water), ammonia or biofuels (e.g., growing algae), which could be transported virtually anywhere. Alternately, an OTEC plant can be used as a deep-water refueling station for ships.
OTEC facilities can serve mariculture and agriculture production. The large quantities of cold ocean waters (around 4 degrees C) pumped from 1,000 meters deep are nutrient-rich and relatively pathogen-free, which provides an excellent medium for growing phytoplankton (microalgae), which is the feedstock for the production of a variety of commercially valuable fish and shellfish,18 as well as growing other algae that can be turned into biofuels. Further, the cold waters can support greenhouses growing cold-weather fruits and vegetables if suitably mixed for the ideal growth temperature either ashore or afloat.19
Additionally, these plants can provide air-conditioning and refrigeration capacity. The deep-ocean cold water can be used as a cooling medium in air-conditioning systems. For example, only 1 cubic meter per second (1 m3/s) of water at a temperature of 7 degrees C (~45 degrees F) is required to produce 5,800 tons of cooling—roughly sufficient to cool 5,800 rooms. Using a 1-meter pipe and about 360 kW of pumping power (compared to 5,000 kW for a conventional AC system) would give an investment payback period of three to four years.20,21 In the case of a co-located computer server firm, this pay-back period would be considerably shorter since the largest energy costs for these farms are those associated with cooling.
OTEC plants can perform mineral extraction. Most economic analyses show that dissolved mineral extraction from ocean water is prohibitively expensive due to energy requirements to pump the large volume of water needed and to separate the minerals from seawater; however, because OTEC plants already will be pumping the water, the cost of the extraction process is the only remaining factor. Investigations are underway to determine the feasibility of combining the extraction of elements dissolved in seawater with ocean energy production.22
Like hydroelectric dams, most of the costs of an OTEC plant are up-front—once the infrastructure is in place, the fuel (solar energy) costs are essentially zero, and day-to-day expenses are only those associated with routine operations and maintenance (O&M).23
OTEC plants offer economic advantages not only on a plant level, but also in terms of the broader economy. Investment in the RD&D for an OTEC infra- structure will create many new employment opportunities, not just directly but also in complimentary and spin-off industries, similar to that seen in the Apollo and Space Shuttle programs.24
OTEC would reduce, both domestically and globally, dependence on fossil fuels, especially petroleum, of which about half of the world’s proven reserves are located in nations that are sponsors of, or allied with, terrorist groups.25,26 Thus, while OTEC-generated electricity and liquid fuel side-products won’t eliminate oil usage, its extensive use could impact the financial re-sources of these terrorist groups.
Finally, since OTEC could supply clean and competitively-priced energy globally, engaging in international partnerships to perform the necessary RD&D would help ensure U.S. leadership in ocean, energy, and environmental issues, and could aid in reasserting our influence in the developing nations that was squandered during the past Administration. Further, by working to ensure that developing nations have access to OTEC, this will reduce their need to develop other energy sources, such as nuclear power programs, with their attendant proliferation and accident risks.27
Leaving aside the technical concerns inherent in developing and commercializing any new technologies, there are also several significant challenges to OTEC, not least among them the cost of generating the electricity; on a per-kilowatt-hour basis, OTEC electricity is expensive compared to coal, hydroelectric, and nuclear power. However, as the technology matures, this cost is expected to drop into the range that will make it competitive with technologies that already have very high energy costs.
Additional challenges include low thermodynamic efficiency. The greater the temperature difference between the heat source and a heat sink, the greater the thermal efficiency of an energy-conversion system; however, the small temperature difference between the source (warm surface water) and the sink (cold deep water) temperature gives OTEC plants a typical thermal-to-electrical energy conversion efficiency of less than 3 percent. In comparison, conventional oil- or coal-fired steam plants, which may have temperature differences of over 200C, have thermal efficiencies around 30 to 35 percent. To compensate for its low thermal efficiency, an OTEC plant has to move significant quantities of water, which increases the power it needs to feed back into the plant’s pumps before any OTEC-generated electricity can be made available to the power grid. For plants larger than about 10 MW, about 25- to 40-percent of the generated power will go to pump the water through the intake and discharge pipes.
Another major challenge OTEC faces is the high capital costs for initial construction. About half of the capital cost of current OTEC designs will be for the heat exchanges, followed by the costs involved with the platform and its moorings, and the sea water pumps and deep seawater pipes, which must extend to around 1,000 m (3,300 ft.) and withstand the pumping of very large volumes of water. For example, a 100-MW OTEC plant will require about 215 m3/s (3.4 million gal/min) of deep sea water, necessitating a minimum pipe diameter of 10 m (32.8 ft.). Such large pipelines would be composed of very expensive materials. In addition, the very large pumps, heat exchangers, and low-efficiency turbines all will add considerably to the construction cost. However, it should be noted that these low-efficiency turbines also could be retrofitted to existing power plants in order to increase their power output and reduce thermal pollution, thus increasing their overall efficiency and profitability.
OTEC plants pose potential ecological consequences. A 100-MW OTEC plant would pump a volume of water similar to that of a major river (i.e., equivalent to the nominal flow of the Colorado River into the Pacific Ocean, or about 3 percent of the Mississippi, 10 percent of the Danube, or 20 percent of the Nile). This will require ensuring that sea water discharges occur at a depth below the bottom of the surface thermocline layer in order to avoid contaminating the surface water and causing poten- tial negative impacts on the local ecology, as well as on the overall thermal efficiency of the OTEC plant.
Perhaps the biggest challenge to eventual OTEC deployment is making the financial case—will it be economical to build and operate? Having in place a consistent regulatory infrastructure, which provides necessary predictability through an orderly, timely, and efficient review of OTEC license applications and operations, along with a supportive legal climate and financial support from the federal government, at least for the initial plants until the technology is proven, will help assure the economic viability of the technology in its infancy. Absent a legal framework and supporting regulatory infrastructure, financing and insuring commercial OTEC operations in the United States may be im-possible.
There are several areas that need to be addressed if OTEC is to become a viable energy option. Unresolved challenges in any of these areas could curtail U.S. work in this field, which could lead the United States to continue its dependence on energy imports and to lose market share in an emerging industry. Obviously, such a situation could have severe repercussions for long-term national energy and economic security. It would behoove the United States to make progress in the areas of: 1) OTEC technologies; 2) enabling legislation; 3) a consistent and predictable regulatory infrastructure for constructing, operating and interfacing with new and existing energy infrastructures; 4) the financial underpinnings for adequately funding the development, construction and operation of these systems; and 5) ensuring an adequate international legal framework is in place to support the peaceful development and commercialization of OTEC technologies.
If these factors are met, and if the technologies can be demonstrated, then the financial support will become more likely and OTEC can begin delivering on its promise.
1. Solar Energy Research Institute, 1989; Ocean Thermal Energy Conversion: An Overview; SERI/SP-220-3024; Golden, CO: Solar Energy Research Institute; 36 pp.
2. Nihous, Gérard C., 2005; “An Order-of-Magnitude Estimate of Ocean Thermal Energy Conversion Resources,” Journal of Energy Resources Technology; Vol. 127, December 2005.
3. The first published reference to the concept of using ocean thermal differences to generate electricity is found in Jules Verne’s “Twenty Thousand Leagues Under the Sea,” published in 1870.
4. Net power is the amount of power generated after subtracting power needed to run the system.
5. Owens, W.L. and L.C. Trimble, 1980; “Mini-OTEC Operational Results;” Proceedings: Seventh Ocean Energy Conference, Washington, D.C., p. 14.1:1-9.
6. Avery, William H. and Walter G. Berl, 1997; “Solar Energy from the Tropical Oceans,” Issues in Science and Technology, Winter 1997.
7. World Energy Council, 2007; 2007 Survey of Energy Resources; pp. 557.; www.worldenergy.org.
8. Energy Independence and Security Act of 2007, P.L. 110-140, Subtitle C, Sections 631-636, Dec. 19, 2007, http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=110_cong_bills&docid=f:h6enr.txt.pdf (last accessed March 29, 2009).
9. FY 2008 Consolidated Appropriations Act, P.L. 110-161, Dec. 26, 2007, Joint Explanatory Statement, p. 558; FY 2009 Omnibus Appropriations Act, P.L. 111-8, March 11, 2009, Joint Explanatory Statement, p. 647.
10. U.S. Department of Energy, 2008; Press Release: “DOE Selects Projects for Up to $7.3 Million for R&D Clean Technology Water Power Projects,” Sept. 18, 2008 (last accessed March 29, 2009).
11. Conference report to accompany the Defense Department Appropriations Act for Fiscal Year 2008, Report 110-434, Nov. 6, 2007, p. 479.
12. Laird, Frank, 2009; “A Full Court Press for Renewable Energy,” Issues in Science and Technology, Winter 2009, p. 55.
13. Kammen, Daniel M., 2004; “Renewable Energy Options for the Emerging Economy: Advances, Opportunities, and Obstacles,” Background Paper for “The 10-40 Solution: Technologies and Policies for a Low-Carbon Future,” Pew Center and NCEP Conference, Washington, D.C., March 25-26, 2004.
14. Gizmag.com, 2008; “Energy Island: Unlocking the Potential of the Ocean as a Renewable Power Source.”
15. Baird, M. and D. Hayhoe, 1993; Energy Fact Sheet, The International Council for Local Environmental Initiatives (ICLEI) information.
16. U.S. Department of Energy, 1990; “The Potential of Renewable Energy: An Interlaboratory White Paper;” SERI/TP-260-3674
17. Craven, John P., and Patrick K. Sullivan, 1998; “Utilization of Deep Ocean Water for Seawater Desalination;” International OTEC/DOWA Association (IOA) Newsletter, Vol. 9, No. 4, Winter 1998.
18. Daniel, T.H., 1985; “Aquaculture Using Cold OTEC Water;” Oceans ‘85 Conference Record; Nov. 12-14, San Diego, CA. Sponsored by Marine Technology Society & IEEE Oceanic Engineering Society.
19. It should be noted that the Natural Energy Laboratory of Hawaii Authority (NELHA) has several commercial tenants making use of deep-sea cold water for various mariculture and nutraceutical products (see http://www.nelha.org/tenants/commercial.html for additional details).
20. Van Ryzin, J.R., and T. Leraand, 1992; “Air Conditioning with Deep Seawater: A Cost-Effective Alternative;” Sea Technology Magazine, Sept., 1992, p. 37
21. Cornell University installed a “Lake Cooling” system in 1999 that uses 100 m deep water from Cayuga Lake to cool the campus. This 20,000 ton system saves Cornell over 20 million kw-hrs annually, even though the air conditioning is only needed in the summer time. Cornell University Lake Source Cooling (LSC) project, Humphreys Service Building, Ithaca, NY.
22. Daniel, T.H., 1993; “An Overview of Ocean Thermal Energy Conversion and its Potential By-Products;” Recent Advances in Marine Science and Technology, ‘92, PACON International, p. 263-272.
23. The operations and maintenance (O&M) of facilities covers all that broad spectrum of services required to assure the built environment is available to, and will, perform the functions for which they were designed and constructed. O&M is comprised of the day-to-day activities necessary for the built entities to perform their intended function. Operations and maintenance are combined into the one term O&M because an entity cannot operate without being maintained.
24. NASA, 1994; “What is the Value of Space Exploration? A Symposium Sponsored by the Mission From Planet Earth Study Office, Office of Space Science, NASA Headquarters, and the University of Maryland at College Park, July 18-19, 1994; National Geographic Society, Washington, D.C.; http://cmex.ihmc.us/CMEX/data/vse/session2.html; (accessed Dec. 1, 2008).
25. Of the fourteen top world oil net exporters listed on the U.S. Department of Energy Web site (www.eia.doe.gov/emeu/cabs/topworldtables1_2.html), two are listed as state sponsors of terrorism by the U.S. Department of State (www.state.gov/s/ct/c14151.htm). The State Department lists Iran, Sudan, and Saudi Arabia as areas of concern for breeding terrorists. Further, Venezuela, which is the third largest supplier of oil to the United States, has a regime that is actively hostile to our interests.
26. Kraemer. Thomas D., Commander, U.S. Navy; 2006; Addicted to Oil: Strategic Implications of American Oil Policy; U.S. Army Warfare College.
27. Included among the nations with no existing commercial nuclear power infrastructure that are considering building nuclear power plants are Algeria, Australia, Chile, Estonia, Israel, Kazakhstan, Latvia, Poland, Switzerland, Thailand, Turkey, and the United Arabic Emirates.There are also nations with an existing commercial nuclear power infrastructure that could benefit from additional assistance, including Argentina, Belarus, Brazil, Bulgaria, Lithuania, and Slovenia.