Power Generation Technology

Remote Renewable Energy Resources
made Possible by
International Electrical Interconnections —
A Priority for All Continents

By Peter Meisen
Executive Director
Global Energy Network Institute
San Diego, CA

Over the past few decades, expanding power grids has 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 of building redundant generation. System interconnections have improved the efficiency of the generation mix, and improved reliability with regards to outages, and stability of frequency and voltage. Yet, approximately 80% of all generation in the world is based on non-renewable fuels, whose emissions have deleterious effect on the environment (the creation of 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 resource sites were connected into existing grids. In addition, the interconnection of existing electrical systems across national borders provide the benefits of a greatly expanded interconnected network.

LONG DISTANCE TRANSMISSION

Current research from CIGRE (*1) (International Conference on Large High Voltage Electric Systems) indicates that long-distance transmission can be made reliable and economically successful for 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 in order to level demand and alleviate power shortages among neighboring systems, exports of excess power from developing nations can provide less expensive peaking 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, foreign power usually displaces only the most expensive peaking generation units. Thus the imported power need only be cheaper than the buyer's marginal cost for peaking power to create an economic win-win situation.

IMPROVED LIVING STANDARDS

From a sociological point of view, the world's environment is rapidly moving out of balance with respect to its ability to support its exploding population. Most projections have world population increasing to 8.5 billion by 2020 (*2), with most all the growth coming from the developing countries. (see Figure 1 - World Population Growth) While population control could relieve many of the environmental problems facing the world, it is unreasonable to expect governmental decrees to accomplish this goal. Population control will occur with two factors. One, 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, refrigeration of food and medicine.

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, as well as to take care of parents when they are old. These insurance births are required because infant mortality is high due to 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)

Common to all social systems with which we are familiar, 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 by wire is a primary measure of modern society.

The 1992 World Energy Conference forecasted energy demand for the next three decades (*4). A doubling of energy demand is projected, again mostly from the exploding growth of the developing world. (see Figure 2 - WEC Energy Scenarios) The ratio of renewable to non-renewable generation varies only slightly, even in the ecologically driven scenario. Clearly the people of the developing nations will be more concerned with survival rather than environmental protection.
The IPCC (Intergovernmental Panel on Climate Change), working for the 1992 Earth Summit, projected a doubling of CO2 emissions over the same time period. (*5) (see Figure 3 - Projected CO2 Emissions) While the effects of this atmospheric experiment are still in dispute, it does appear that a prime solution to this global problem is to effect a transition by tapping many of the potential renewable resources to areas of electrical demand via long distance high voltage transmission lines.

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

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)

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.

THE INTERCONTINENTAL TIES

The concept of intercontinental connections was addressed in detail at recent meetings of the IEEE/PES (Institute of Electronic and Electrical Engineers - Power Engineering Society) (January 1992 New York, NY, and January 93 Columbus, OH) 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, clearly, that inter-regional interconnections were feasible and desirable today. In fact, it was stated that there has never been a known economic failure (save warring disruptions), and every interconnection has proven to be of greater economic benefit that the justification for construction in the first place. (*7)

In many cases these regional links would actually be inter-continental ties. Several schemes were presented, e.g., a connection between South and North America to capitalize on the great hydro resources of South America. This intertie was first proposed in 1971, when the technology of long distance high-voltage transmission was limiting. Today, however, this technology is available and proven. Less polluting power sold to the North will bring economic benefits to Latin America. While the cheaper electricity would aid the economies in North America, the dollars to Latin America could be used for the many developmental needs as well as debt repayment.

Additional ties that are presently in feasibility study include interties between Central Africa to Egypt, with connections to the Middle East countries. (*8) This possible 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 power station are:

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

As proposed by Dr. Luigi Paris and Dr. Nelson DeFranco, (*9) Inga energy can be delivered to Europe at a price that is competitive with domestic coal or nuclear generation in Europe.

The transnational connections from Zaire could 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. (see Figure 4, Africa to Europe map) 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 in order 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 cable installation. Selecting an operating voltage of +600 kV, tower line space could be minimized for the overhead portion and oil-filled cable could be used for the under water installation. All of the system is based on proven technology and appears to be feasible with low risk. The underwater cabling between Spain and Morocco at the Strait of Gibraltar is now under proposal.

With the end of the Cold War, Russian and East European engineers are working to upgrade and strengthen the former Comecon system for future integration into the Western European grid. Another opportunity lies with the regional concern over the Chernobyl style nuclear plants in Eastern Europe. Shutdown of these plants is difficult because the power is needed in the East, and the West is investing heavily in safeguarding against further accidents. Imported power may be an alternative.

Russian and Alaskan power system planners have 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, Siberia and into the eastern Soviet grid. It is only a short step from that scenario to one that will include an interconnection between Russia with its Asian neighbors: Japan, North and South Korea and China.

The six nation Gulf Cooperation Council (Kuwait, Saudi Arabia, Bahrain, Qatar, United Arab Emirates, and Oman) have commissioned a HVAC and DC system along the Persian Gulf(*11). All states run on 60 Hertz except Saudi Arabia at 50 Hertz, requiring a AC/DC converter linkage of the asynchronous systems.

Clearly, the most critical world region for future energy demand will be India, China and Southeast Asia. Over 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. (*12) 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.

BENEFITS AND OPPORTUNITIES

Our quality of life in the developed world is totally related and a function of our 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 power needs. As one 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 the income from energy sales would provide needed revenue for governmental programs intended to alleviate poverty in the region. The export of a renewable resource does not reduce the potential richness of the producing country and therefore does not compromise its future development. Instead the scheme provides impetus for continued development, plus the ability to repay existing debt.

An examination of just a few areas in the world where renewable energy source exist will provide 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, Middle East, Russia, India, China and Australia.
• Geothermal potential exists around the Pacific Ocean's ring of fire, and in the rift valley of Africa

The large number of locations where development is possible shows the possibility for world-wide cooperation in a technology that can serve as a common point of interest for all countries. 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. (*13) 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 comes on the heels of the Earth Summit last year in Rio. Noel Brown, North American Director of the United Nations Environmental Program states that tapping of remote renewable resources is one of the most important projects to further the cause of environmental protection and sustainable development. (*14)

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 do we provide sustainable development and environmental protection for the long term must be high on the list of critical issues of all nations.

Bibliographic References (*1) - (*14)

*1. Present Limits of Very Long Distance Transmission Systems, Committee 37, CIGRE 1984 paper, L. Paris, G. Zini, M. Valtorta, G. Manzoni, A Invernizzi, N. DeFranco, A. Vian

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

*3. A Model for the Quality of Life as a Function of Electrical Energy Consumption, Bangladesh Institute of Technology and University of Engineering and Technology, Vol. 16, No. 4 Energy, 1991, M.S. Alam, B.K. Bala, A.M.Z. Huo, M.A. Matin

*4. Energy for Tomorrow's World, World Energy Council, WEC Commission's Global Report, September 1992

*5. Climate Change: the IPCC Scientific Assessment, J. Houghton, G. Jenkins, J. Ephraums, Cambridge University Press, Cambridge, 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. International Workshop on the Limits of Long-Distance High-Voltage Power Transmission and the Corresponding Economic, Environmental, and Sociopolitical Implications, Winnipeg, Canada, July 1991

*8. Grand Inga Case, Luigi Paris, IEEE Power Engineering Review, Vol. 12, No. 6, June 1992

*9. op. cit., CIGRE

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

*11. Planning of the Gulf States Interconnection, J. Al-Alawi, S. Sud, D. McGillis, for the Gulf States Cooperation Council, 1991

*12. op. cit. WEC regional reports, Pacific and South Asia

*13. Is it Possible and Expedient to Create a Global Energy Network?, Y. Rudenko, V. Yershevich, International Journal of Global Energy Issues, Vol. 3, No. 3, 1991

*14. United Nations Environmental Program, North American Director Noel Brown, March 1992, in a letter to Ros Kelly, Australian Minister of Environment