Authors

• T. J. Hammons, IEEE Chairman International Practices for Energy Development and Power Generation, Glasgow Univ., Scotland, UK
  
  
• J. A. Falcon, President, American Society of Mechanical Engineers, New York, NY, USA
  
  
• P. Meisen, Executive Director, Global Energy Network Institute, San Diego, CA, USA.

Overview

Over the past few decades, international electrical interconnections have become increasing widespread as technology has improved and the benefits of integrated systems are realized. System interconnection facilitate reduced requirements for spinning reserve, improved efficiency, load leveling between time zones and seasonal variations, less fossil fuel emissions and the harnessing of remote renewable energy sources.

Expanding power grids have proven to be both economically and environmentally desirable. The utilization of the time zone and seasonal diversity that may exist between adjacent power systems can postpone or eliminate the necessity for commissioning new generating plants. System interconnections have improved the efficiency of the generation mix, reliability with respect to outages, and power system stability, frequency and voltage. Yet approximately 80% of all generation in the world is based on non-renewable fuels, whose emissions harm the environment, creating greenhouse gases, acid rain and toxic waste.

With numerous sites around the world that boast of energy sources like hydro, tidal, solar, wind and geothermal, it is reasonable to project the benefits for the future if these renewable energy resource sites were connected into existing grids. In addition, the interconnection of existing electrical systems across national borders provides the benefits of a greatly expanded interconnected network.

Long Distance Transmission

Studies performed by CIGRE (International Conference on Large High Voltage Electric Systems) [1] indicates that long-distance transmission can be made reliable and economically successful for distances of up to about 6500 kilometers with HVDC (High Voltage Direct Current) and 4800 kilometers with HVAC (High Voltage Alternating Current). This would permit inter-regional and even intercontinental power delivery from remote sites where large renewable energy sources may be found. An inventory of some of the best renewable resources shows them to be located throughout much of the developing world -- Latin America, Africa and Asia, as well as the northern latitudes of Canada, Alaska and Russia. Just as power is presently being purchased and sold every day to even out demand and alleviate power shortages among neighboring systems, so exports of excess power from developing nations can provide less expensive electricity for the industrialized countries, and financial resources for third-world countries.

Billions of dollars could be saved by sharing this untapped potential, and to a large extent, much future demand could be satisfied by wheeling rather than by building new plants. Savings from wheeled power are well established, and are reflected in reduced customer costs for the buyer and reduced unit costs for the seller. Since many countries are still unwilling to rely on too large a percentage of imported power for national security reasons, imported power usually displaces only the most expensive peaking generation units. Today, political enemies of old are quickly becoming trading partners. Just two months after the Berlin Wall was torn down, East and West Germany initiated the process of grid interconnection. Reported within days of the Israeli/PLO peace accords was the proposal to link the Israeli and Arab networks for mutual economic benefit.

The imported power need only be cheaper than the buyer's marginal cost for peaking power to create an economic win-win situation.

Total dependence of energy supply on a neighboring nation is unrealistic, yet emergency and reserve margin sharing quickly turns into economy energy exchanges as trust builds between parties. In any case, power transmission per circuit is usually limited to the amount of power the receiving system can afford to lose so to not cause instability in their system.

An additional challenge for utilities today with regard to power transmission are Electro-Magnetic Fields (EMFs). It has become almost impossible to site transmission in some areas due to this cancer scare among the general public. Millions of dollars are presently spent researching the issue, with credible people coming down on each side. Epidemiologists state a perceived increase in childhood leukemia from 1 case in 10,000 to 2 cases in 10,000. Extensive studies on lineman and telephone workers have shown no increase in risk. The authors view the EMF issue as a debate of the privileged in the developed world. Having the highest standard of living in the world, much of it supported via electricity, we live to an average age of 70 - 80 years old. For people in the first world, an EMF policy of "prudent avoidance" is a sound one for the time being. In most developing countries, having limited electricity, their living standard is dismal and supports an average life expectancy of 50 - 60 years. Their desire is for more electricity to improve their quality of life, and EMF is not an issue.

Improved Living Standards

From a sociological point of view, the world's environment is rapidly moving out of balance in respect of its ability to support an exploding population. Most projections have world population increasing from 5.3 billion in 1990 to about 8 billion in 2020 [2], with almost all the growth coming from the developing countries. Predictions vary to the year 2050, but most population experts project about 10 billion people by mid-century. While population control could relieve many of the environmental problems facing the world, it is unreasonable to expect governmental decrees to accomplish such a goal. Population control will occur through two factors. Firstly, people around the world must move towards a rational approach to family planning. Secondly, energy in sufficient quantities must be available for basic infrastructure needs such as development of clean water resources, sanitation facilities, and refrigeration of food and medicine. Projected world population growth is illustrated in Figure 1.

In third-world countries, large families are deemed necessary to ensure that some of the survivors will be around to help with the work of sustaining the family, and to take care of parents when they are old. These "insurance births" are required because infant mortality is high as a result of inadequate health care, non-potable water and malnutrition. Thus, not only are infants at risk, but children as a group. When food and health-care systems can be sustained, fewer children are necessary for each family to function as working and contributing members of the community, and birth rates fall along with infant mortality [3].

In all social systems of the developed world, energy in the form of electricity provides for the efficient utilization of resources to supply food, shelter, health care, sewage disposal, transportation, communication and education. Clearly, power via transmission lines is a primary requirement of modern society, yet people in developing nations are more concerned with survival than with environmental protection.

World Energy Demand

The 1992 World Energy Conference has provided a comprehensive long-term global and regional energy perspective to the year 2020 [4]. A doubling of energy demand is projected, again mostly from the exploding population growth and the subsequent energy needs of the developing world. Three global energy cases representing different assumptions in terms of economic development, energy efficiencies, and environmental impact have been considered.

• The Reference (REF) Case, in essence the same developed by the World Energy Conference for the Montreal (1989) Congress, which forecasts that future energy demand will rise from 8.7 Gigotonnes of oil equivalent (Gtoe) in 1990 to 13.3 Gtoe in 2020, the other two cases are variants included to illustrate sensitivities to changes in the basic assumptions.
  
  
• The Enhanced Economic Development (EED) Case, which assumes a somewhat higher economic growth in developing countries (4% GNP growth over 3%), and suggests that global energy demand will rise to 17.2 Gtoe.
  
  
• The Ecologically Driven (ED) Case, which assumes the same economic growth as for the REF Case but with a sharper improvement in energy efficiency, shows that energy demand will rise to only 11.2 Gtoe by the year 2020.

Global energy mix in the year 2020 for these three assumptions is depicted in Table 1 and in Figure 2. It is seen that the WEC estimates commercial fossil fuels will continue to dominate the energy mix to the year 2020, and are likely to continue to do so far into the next century. From a total fossil fuel ratio (that is, the ratio between commercial fossil fuel consumption and total fuel use) at 78% in 1990, it becomes 73% in the REF Case, 75% in the EED Case, and 63% in the ED Case in the year 2020.

New renewable energy sources will be seen to play an increasing role in the energy mix as we move into the next century. They should increase by 2.5 to 7.5 times current production, while hydro generation is expected to double by the year 2020. The contribution from nuclear power is also expected to double, but this will require resolution of some of the issues of public concern, such as technical safety in operation, management skills, effective international inspection, and safe long-term disposal of radioactive waste. Cost effective development and implementation of new renewable energy resources over the coming decades will be necessary to maximize the contribution they can make to the diversification of energy sources and the long term security of supply. Up until today, their lack of commercial viability limited large scale implementation of new renewables in the world energy system because of heavy weighting of initial capital cost.

CO₂ Emissions and Environment

The Inter-Governmental Panel on Climate Change (IPCC) working for the 1992 Earth Summit projected a doubling of CO2 emissions over the period to 2020 [5]. Although the consequences of these emissions are still in dispute, it does appear that a prime solution to the global problem is to effect a transition by tapping many of the potential renewable resources and transmitting the energy electrically to areas of high demand by high voltage transmission. Industrial CO2 emissions predicted by the IPCC on Climate Change are illustrated in Figure 3. A 60% reduction in CO2 from 1990 levels is recommended to stabilize CO2 concentrations in the atmosphere in respect of climate change.

Many in the environmental community are promoting demand side management as one answer to our environmental problems. While demand side efficiency is important for advanced economies, this will not solve the energy needs of the growing economies in the developing world.

Nuclear advocates rightfully state that fission produces no CO2 pollution, and is therefore an good solution to the greenhouse problem. Yet, nuclear power is politically impossible to build in many countries around the world, and except for Japan and France, has failed economically when compared to other generation options. Another Chernobyl-style accident could cause a political shift and curtail nuclear development even further.

Engineers have the means and the mandate to generate benefits beyond system reliability and efficiency, which have been hallmarks of the profession. In 1971, The United Nations Natural Resources Committee proposed the interconnection of central Africa to Europe and Latin America to North America as a means of displacing polluting generation in the North with renewable energy resources from the South [6]. At that time the technology of long-distance high-voltage transmission was in its infancy. Today this technology is available and proven.

Twenty years ago, architect and inventor Dr. R. Buckminster Fuller proposed interconnecting regional power systems into a single, continuous worldwide electric energy grid as the number one solution to solve many of the world's most pressing problems. While this vision is still years away, Fuller foresaw power grids as a means of improving the standard of living for the impoverished, preserving the environment and enhancing international trade and cooperation.

Intercontinental Ties

The concept of intercontinental connections was addressed in detail at meetings of the IEEE/PES (Institute of Electrical and Electronic Engineers - Power Engineering Society) (January 1992, New York, NY [7], and February 1993, Columbus, OH [8]) where specialists from utilities, the United Nations, and the World Bank discussed the potential of tapping remote renewables using long-distance, high-voltage interconnections.

Panelists, who were engineers from the United States, Canada, Egypt, Brazil, India, Italy, the United Kingdom and Saudi Arabia, were experts in the field of system planning, design, construction and operation of high-voltage systems in all parts of the world. The consensus was that inter-regional interconnections were feasible and desirable today. It was stated that there had never been a known economic failure (save disruption through war), and every interconnection had proved to be of greater economic benefit than was the justification for its construction in the first place [7].

In many cases these regional links would be inter-continental ties. Several technically feasible concepts were presented - for example, a connection between the two American continents to capitalize on the great hydro resources of South America. Power sold to the North would bring economic benefits to Latin America. While cheaper electricity would aid the economies in North America, reimbursement to Latin America could be used for developmental needs as well as for debt repayment.

Additional ties under feasibility study include interties between Central Africa and Egypt, with connections to the Middle East countries [7,8], and from Iceland to the UK [9]. A major link between Africa and Europe has its basis in the vast hydro energy available from the Zaire River. The Grand Inga power station on the Zaire River represents a typical example of power supply that can be exported using international transmission lines. The characteristics of this potential development are:

• 30,000MW of installed capacity
  
  
• 240 billion KWh annual energy production
  
  
• Less than $1,000 per KW installed cost
  
  
• Low environmental impact.

In 1984, Dr Luigi Paris, Energy and Transmission consultant of Rome, Italy and Nelson de Franco of the World Bank's Energy Infrastructure Department, have suggested Inga electricity could be delivered to Europe at a price competitive with fossil generation it would supplement or replace [1]. Recently, Yehia Abu-Alam of the Science, Technology, Energy, Environment, and Natural Resources Division of the United Nations further calculated that the energy cost of Inga hydropower to Europe would be 25% cheaper than domestic European nuclear power, and half the cost of European coal generation [8]. See Table 2 and Figure 4.

Transnational connections from Zaire have several potential land corridors. Transmission lines could traverse African Countries in the western, central and eastern portions of that continent, terminating in Spain, Italy, Greece or Turkey. Because of the long distance, HVDC would be mandatory for transmission, requiring six to ten bipolar lines. These lines, traversing desert and sea, would require careful siting to minimize exposure to harsh environments where, for example, tower footings would be unstable in the sand, and where excessive depth of the Mediterranean Sea would limit installation of the cables. Selecting an operating voltage of +600 kV, tower line space could be minimized for the overhead portion and paper-insulated submarine cable could be used for the underwater installation.

Underwater cabling is commonplace, with DC links between England and France, and across the Cook Strait in New Zealand for just two examples. The plan for a submarine cable between Spain and Morocco at the Strait of Gibraltar is being studied. The whole African system is based on proven technology and appears feasible with low risk. The proposed Zaire/Europe development is illustrated in Figure 5.

Possibilities of a submarine power link between Iceland and the UK have been investigated for several years [9]. The National Power Company of Iceland, Landsvirkjun, which could provide un-utilized surplus of potential hydro-power amounting to 25,000 -30,000 GWh/year and geothermal power useful for electricity generation of at least 20,000 GWh/year, have recently stepped up its investigation of the link. Conclusions were released early 1993 in the form of a pre-feasibility study on the proposed development. The study was conducted with the assistance of Pirelli Cables (Italy and UK), Vattenfall Engineering (Sweden) and local consultants.

Results affirm the technical viability of the link. Particulars of the proposed 2400 MW development, including its economic prospects, are summarized in Table 3.

Pirelli's review includes technical particulars of a "state of the art" design as well as a "near future" design (3-5 years). The cost of power delivered by the link is based on an economic analysis of suitable generation from contemplated East Iceland hydro electric plants.

The Commonwealth of Independent States (CIS) and Alaskan power system planners recently met to discuss an East/West intertie between Alaska and Siberia [10]. While this interconnection may be years away, enormous hydro and tidal potential exists in these northern latitudes. However, the load is thousands of kilometers away - in Asia and the United States. In this connection, a promising possibility would be to install an 8000 kilometer HVDC line from the US/Canadian grid, across Alaska, the Bering Strait and Siberia and into the eastern Russian grid. It is only a short step from that scenario to one that includes an interconnection between Russia and its Asian neighbors: Japan, North and South Korea and China. See Figure 6.

With long distance HVDC transmission, one of the world's premier tidal sites could be developed at Penzhinskaya in Russia's Okhotsk Sea. This power could be fed into this multi-terminal system to Asian markets, or used for hydrogen production and shipped to these same customers. Potential tidal power sites considered for development worldwide are summarized in Table 4. See references [11,12] for Tidal Power Generation prospects.

The six nation Gulf Cooperation Council (Kuwait, Saudi Arabia, Bahrain, Qatar, United Arab Emirates, and Oman) have commissioned a HVAC and HVDC system along the Persian Gulf [13]. All states operate at 50Hz except Saudi-Arabia which operates at 60Hz. AC/DC/AC couplers link Saudi Arabia to neighboring systems.

Clearly, the most critical world region for future energy demand will be India, China and Southeast Asia. More than half the world's population lives in this region, and energy demand is projected to surpass that of the first world by the turn of the century [14]. The enormous hydro, solar, and tidal resources of the region offer great opportunity for long term sustainable development. In each of these cases, the state of the art in network integration transcends national boundaries. The hurdles to tapping these immense renewable reserves are political in nature, not technical.

East-West European Interconnections

With the end of the Cold War, the Commonwealth of Independent States and East European engineers are working to upgrade and strengthen the former Comecon Electricity Grid system [15,16]. Synchronous coupling of the power grids on either side of the former Iron Curtain makes economic sense as reported by a meeting sponsored by UNESCO and the International Union of Producers and Distributors of Electrical Energy (UNIPEDE). At a few points along the former Iron Curtain, AC/DC/AC interconnections with or without DC lines already interconnect the two systems asynchronously at first.

The DC technique can be used in two ways: without or with DC lines. The first is the way it is done today, using back-to-back stations along the old border between East and West Europe. These stations would be strung along the border between the synchronized systems. The other approach is to build several DC lines, penetrating some distance into both synchronized systems to form so called "staples". The conversion stations are then at either end of the line and also, if necessary, at intermediate points forming a multi-terminal configuration.

An advantage of back-to-back converter stations is their total control over electric power flowing through the two electric systems they join, while in the event of serious incident, they prevent cascading collapse. Stapled systems using DC lines gives good control of power flow between the systems. DC lines are themselves cheaper than AC lines because their insulation voltage is reduced by a factor of root two. DC lines allow for simple separation in the event of faults at either end of the system. Since DC interconnections decouple the requirement of common frequency, no stability problems are anticipated.

In general, existing AC transmission lines are preferred for the interconnections, as this method allows a better coordination between systems on both sides of the border at optimized cost and in a far more flexible manner than DC systems would allow. International collaboration on this technical issue is essential if fully synchronized interconnections are to go ahead. Within an interconnected electricity system, frequency must be cooperatively managed and collectively stabilized among all members of the power pool.

Synchronization may have to follow three stages. First would come the Czech Republic, Slovakia, Poland and Hungary; next, countries like Bulgaria, Romania, and Turkey. Finally, extensions would be possible into other countries. Additionally, system planners in Europe have designs to interconnect with North Africa via underwater cable to Gibraltar, Italy and through the Middle East. UNIPEDE reports that large transfers of energy across Europe will be possible in the long term.

Another opportunity lies with the regional concern over Chernobyl style nuclear plants in Eastern Europe [16]. Decommissioning of such plants is difficult at this time because the power is needed in Eastern Europe. Western Europe is investing heavily in safeguarding against further nuclear accidents. Imported power may be an alternative.

Benefits and Opportunities

Quality of life in the developed world is directly related to and a function of the electrical infrastructure. In a similar manner, the striving for improved living standards in the developing nations is a direct function of the supply of their electricity requirements.

As an example, the social benefits of the Grand Inga project would be significant for developing countries in Africa, since the energy produced comes from a renewable source, and income from energy sales would provide needed revenue for governmental programs intended to alleviate poverty. The export of a renewable resource does not reduce the potential richness of the producing country, and therefore does not compromise its future development. The scheme provides impetus for continued development, and enhances the ability to repay existing debt.

An examination of just a few areas in the world where renewable energy sources exist provides some idea of the potential of the grand plan for intercontinental exchange of energy:

• Large untapped hydro sites can be found in Latin America, Canada, Alaska, Siberia, Southeast Asia, and Africa.
  
  
• Tidal sites are found in Argentina, Canada, Siberia, China, Australia, and India.
  
  
• Solar potential rings the earth in Mexico, the United States, Africa, the Middle East, Russia, India, China and Australia.
  
  
• Geothermal potential exists around the Pacific Ocean's "ring of fire", in the rift valley of Africa, Australia and an Iceland.
  
  
• Wind potential exists on all continents, with geography providing some ideal sites in mountains and along coastlines.

The potential capacity of these resources is massive. To state but a few examples -- Asea Brown Boveri reports that the world presently uses 14% of the exploitable hydro, and that a doubling would reduce CO2 emission on the planet by one-third. [17] Variable speed wind turbines have reduced costs to about $.05/KWh, and the Union of Concerned Scientists projects that much of the U.S. Midwest States new capacity demand of 2005 can be wind generated with no loss of reliability or increase in cost. [18] The tidal power of the Kimberly region in northwest Australia has the potential of eight times the present energy demand of the entire continent [19]. Given the remote nature of this and other similar sites, in addition to electrical generation, hydrogen production would also be a logical development scheme for use in the transportation sector. This would again provide a fuel that is essentially combustion-clean, and extend the life of petroleum reserves on the planet.

Today, over 400MW of solar thermal power provides utility-scale electricity to Southern California at competitive peak rates, $.08 - $.12/KWh. For the next century, Sanyo Electric of Japan has proposed a grid-connected, worldwide photovoltaic energy system, using solar cells with 10% conversion efficiency and an area of 800km x 800km (about 4% of the world's deserts). Sanyo's Kuwano projects the scheme would generate the equivalent of the world's petroleum use in 2000 (1.4 x 10,000,000,000 kiloliters per year -- 10 to power of 10). [20]

Clearly, renewable resources are abundant, yet site specific, and often in remote locations across political boundaries. At present, the only renewable resource that adds a significant portion to the global generation mix is hydro. Less than 100MW per year of new capacity comes from the other renewables. The energy demands of 250,000 new people per day cannot be met at this rate. While many development experts emphasize small, localized generation as the priority to meet the immediate survival needs in rural developing countries, this micro generation cannot meet the demands of 100 million new people every year. A combination of both small and large scale development of renewable energy resources seems essential.

Using the business-as-usual scenarios of the World Energy Conference portends a future of further environmental pollution. With the costs of variable speed wind turbines and solar thermal generation now becoming cost competitive with base-load coal and gas-fired peaking rates, vast renewable sites in remote locations can now be available to meet this exploding demand with less impact on the environment. As stated in the new volume, "Renewable Energy: Sources for Fuels and Electricity", most of the electricity produced from these sources would be fed into large electrical grids and marketed by electric utilities [21].

In contrast to the WEC scenarios, Johannsen, Kelly, et al propose that at least 60% of the world's generation could be met from renewable resources by 2025, and that higher levels could be realized if nations should desire greater CO2 reductions. Of importance is the conclusion that the renewable energy development indicated in their Renewables Intensive Global Energy Scenario represents a tiny fraction of the technical potential of renewable energy. See Figure 7.

Of concern for all is China's coal-fired development, adding a new thermal power plant every month. Continuing down this path will negate the efforts of the rest of the world to reduce CO2 emissions to levels recommended by the IPCC for the Earth Summit. Yet China is geographically surrounded by renewable resource options: hydro in the Himalayas and the Lena, Yenisey and Ob Rivers of Siberia; the Tibetan plateau and Mongolian deserts offer tremendous solar radiation; and several tidal sites exist along the Yellow, East and South China Seas No one can deny Asia's desire for improved living standards, yet everyone on the planet is ultimately affected by their energy decisions in the next few years.

The large number of locations where development is possible shows the scope for world-wide cooperation in a technology that can serve as a common point of interest for all countries. As noted by Yuri Rudenko and Victor Yershevich of the Russian Academy of Sciences, the creation of a unified electrical power system would not be an end in itself [22]. Rather, it was their view that a unified system would be the natural result of systems that demonstrated benefits in terms of economics, ecology and national priorities.

Possibly the most encouraging endorsement for the linking of renewable resources is a result of the Earth Summit in June 1992 in Rio de Janeiro. Noel Brown, North American Director of the United Nations Environmental Program, stated that tapping of remote renewable resources is one of the most important projects to further the cause of environmental protection and sustainable development.

Engineers have the responsibility of designing systems for the long term sustainability of our planet. We have seen the consequences of past errors, and that of short term thinking. The question of how we can provide sustainable development and environmental protection for the long term must be high on the list of critical issues of all nations.

Figure Captions

(in order of appearance in paper)

Figure 1. Projected Global Population

Table 1. Global Fuel Use, Past and Future Energy Mix (Gigatonnes of Oil Equivalent)

Figure 2. Alternative Energy Futures

Figure 3. Industrial CO2 Emissions

Table 2. Cumulative present worth of revenue requirements in 2002 and levelized cost per megawatthour

Figure 4. Inga hydro generation project: Hydro vs. European nuclear or coal

Figure 5. Line Routes to Europe from Grand Inga (use Abu-Alam map from IEEE Review of July 1993)

Figure 6. Multi-terminal interconnection between Russia and North America

Table 3. Proposed Iceland/ UK Cable Connection

Table 4. Tidal Power Sites Considered for Development Worldwide.

Figure 7. Renewables Intensive Global Energy Scenario

References

[1] Paris, L. and Zini. G. "Present Limits of Very Long Distance Transmission Systems." CIGRE Committee 37 Report, Paris, France, 1984.

[2] World Population Prospects, United Nations, Department of International, Economic and Social Affairs, 1988.

[3] Alam, M.S., Bala, B.K., Huo, A.M.Z. and Matin, M.A." A Model for the Quality of Life as a Function of Electrical Energy Consumption." Bangladesh Institute of Technology and University of Engineering and Technology, 1991, Vol. 16, (4).

[4] Ager-Hanssen, H.J. "Energy for Tomorrow's World - The Realities, the Real Options and the Agenda for Achievement." Keynote Address, 15th World Energy Council Congress, Madrid, Spain, 20-25 September 1992, pp.1-7.

[5] Houghton, J., Jenkins, G. and Ephraums, J. "Climate Change: The IPCC Scientific Assessment." Cambridge University Press, UK, 1990.

[6] "Environmental Problems of Energy Production and Utilization." United Nations Committee on Natural Resources report to the Economic and Social Council, January 1971.

[7] Hammons, T.J., Falcon, J.A., Bateman, L.A., Lemay, J., Kern, E.C., Paris, L., Wolfe, M. H., Al-Shehri, A.M., El-Amin, I. M., Opoku, G. and Meisen, P. "Remote Renewable Energy Resources: Long-Distance High Voltage Interconnections. "IEEE Power Engineering Review, Vol. 12, (6), 1992, pp.3-25.

[8] Hammons, T.J,. Vedavalli, R., Abu-Alam, Y., de Franco, N., Drolet, T. and McConnach, J .,"International Electric Network History and Future Perspectives on the United Nations and World Bank." IEEE Power Engineering Review, Vol. 13, (6), 1993, pp 12-24.

[9] Hammons, T.J., Olsen, A., Kacejko, P. and Leung, C.L., "Proposed Iceland/United Kingdom Power Link - An Indepth Analysis of Issues and Returns." IEEE Transactions on Energy Conversion, Vol. 8, ( ), 1993, pp - .

[10] "The Potential of an Electrical Interconnection between Russia and North America." International Workshop, Anchorage, Alaska, USA, January 1992.

[11] Hammons, T.J . "Advanced Power Generation Technologies - Tidal Power." Proceedings IEEE, 1993, Vol. 80, (3), 1993, pp.

[12] Hammons, T.J., Aisiks, E.G., Baker, G.C., Craig, J.W., Frau, J.P. and Thompson, I.,"Tidal Power." IEEE Power Engineering Review, Vol. 13, (3), 1993, pp - .

[13] Al-Alani, J ., Sud, S. and McGilles, D. "Planning of the Gulf States Interconnection". Report prepared for the Gulf States Cooperative Council, 1991.

[14] WEC Regional Reports CRS1 and CSR2 (South Asia and Pacific including China), 15th World Energy Council Congress, Madrid, Spain, 20-25 September 1992.

[15] Hammons, T.J., Covino, M., de Vasconcelos, A.V., Guieze, J.L., van Reeuwijk, P., Esser, C., Grossman, R.G., and Burton, N., "EC Community Policy on Electricity Infrastructure, Interconnections, and Electricity Exchanges." IEEE Power Engineering Review, Vol. 13, (5), 1993, pp

[16] Persoz, H., and Remondeuloz, J. "Cooperation in the Field of Electric Systems between Eastern and Western Europe," Proceedings of the World Energy Council Congress, Madrid, Spain, 20-25 September 1992, paper 4.2-09, pp. 149-165.

[17] Bohlin, S., Eriksson, K., Flisberg, G., ABB Power Systems, Ludvika, Sweden, "Electrical Transmission", World Energy Coalition Conference, 1991.

[18] Brower, M.C., Tennis, M.W., Denzler, E.W., Kaplan, M.M., "Powering the Midwest: Renewable Electricity for the Economy and the Environment", Union of Concerned Scientists Report, 1993.

[19] Charles, B., "Australian Tidal Power", Engineering Times, Institute of Engineers Australia, June 1993.

[20] Kuwano, Y., "GENESIS Project", Sanyo Electric Company, International Solar Energy Society, 1991

[21] Johanssen, T., Kelly, H., Reddy, A., Williams, R., "Renewable Energy - Sources for Fuels and Electricity", Island Press, 1993, pp 1 - 7.

[22] Rudenko, Y. and Yershevich, V. "Is it Possible and Expedient to Create a Global Energy Network?" International Journal of Global Energy Issues, Vol. 3, (3), 1991.