Transmission & Distribution International, December, 1992

Worldwide Interconnections
May Be An Idea Whose Time Has Come

By Peter Meisen, Executive Director, Global Energy Network Institute

xpanding power grids has proven to be both economically and environmentally desirable since the time-zone and seasonal diversity that exists between adjacent power systems can postpone or eliminate the necessity of building redundant generation. Approximately 80% of all generation presently is based on non-renewable fuels, which create greenhouse gases, acid rain and toxic waste. With 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 sites were connected into existing grids. 

Long Distance Transmission

Current research indicates that long-distance transmission can be made reliable and economically successful for up to about 6500 km with HVDC and 4800 km with HVAC, which would permit intercontinental power delivery from remote sites where large renewable energy sources may be found. Just as power is purchased and sold every day to level demand and alleviate power shortages among neighboring systems, exports of excess power from developing nations can provide inexpensive electricity for the industrialized countries and cash for third-world countries.

Fig. 1. Line routes to Europe from Grand Inga

Billions of dollars could be saved by sharing this untapped potential, and to a large extent, future demand will 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. 

Improved Living Standards
From a sociological point of view, the world's environment is rapidly moving out of balance with its ability to support the world's exploding population.

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 if people around the world move toward a rational approach to family planning and provide sufficient electricity for the basic infrastructure needs of clean water, waste disposal, and refrigeration of food and medicines.

In third-world countries, large families ensure that some family members survive to help sustain the family, as well as to take care of parents when they are old. Because of inadequate health care, non-potable water and malnutrition, infant mortality is high and "insurance births" are necessary. Not only are infants at risk, but children as a group. When food and health-care Systems can he sustained, birth rates fall along with infant mortality because fewer children are necessary for each family to function as working and contributing members of the community.

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.

Twenty years ago, 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 pressing problems. While he envisioned creating economical power systems, Fuller also saw power grids as a way to reduce human suffering, preserve the environment and make war obsolete.

The Intercontinental Ties

Intercontinental connections were addressed in detail at the l992 Winter Power Meeting of the IEEE/PES in New York where a panel session was held on the potential of tapping remote renewables using long-distance, high-voltage interconnections. Panelists, who were engineers from the United States, Canada, 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. In many cases these regional links actually would be intercontinental ties. Several schemes were presented.

In 1971, the United Nations Natural Resources Council proposed the connection between South and North America to capitalize on the great hydro resources of South America. Less polluting power sold to the North will bring economic benefits to Latin America. Additional ties being studied include interties between Central Africa and Egypt with connections to Middle-East countries. The possible link between Africa and Europe is based on the vast hydro energy available from the Zaire River.

The Grand Inga power station on the Zaire River represents a typical example of the power supply that can be exported using international transmission lines (Fig. 1.). The characteristics of this potential power station are:

• 30,000 MW of installed capacity.
• 240-billion kWh annual energy production.
• Less than $1000 per kW installed cost.
• Low environmental impact.
• The Inga energy can be delivered to Europe at a price that is competitive with other energy sources in Europe, according to Luigi Paris, energy transmission consultant of the Faculty of Engineering at the University of Pisa.

Fig. 2. Transnational connections

The transnational connections from Zaire have several potential land corridors (Fig. 2). Transmission lines could traverse African countries in the western, central and eastern portion 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 in order to minimize exposure to harsh environments where, for example, tower footings would he unstable in the sand and where excessive depth of the Mediterranean Sea would limit cable installation. Selecting an operating voltage of 600 kV, towerline space could be minimized for the overhead portion and oil-filled cable could be used for the underwater installation. The system is based on proven technology and appears to be feasible with low risk.

Russian and Alaskan power system planners recently met to discuss an east/west intertie between Alaska and Siberia. In this connection, it might he possible to install an 8OO-km HVDC line from the U.S./Canadian grid across Alaska, the Bering Strait, Siberia and into the eastern Soviet grid. Only a short step from that scenario is the possibility of making an interconnection between Russia and its Asian neighbors: Japan, North Korea, South Korea and China.

Similarly Russian and East-European engineers are working to upgrade and strengthen the former Comecon system for future integration into the Western European grid.

Benefits And Opportunities

Quality of life depends on the electrical infrastructure in the developed world. 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 development. Instead, the scheme provides impetus for continued development, and the ability to repay existing debt.

An examination of a few areas in the world where renewable energy sources exist provides some idea of the potential of the 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.

The large number of locations for possible development indicates the possibility for worldwide 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. Rather, their view was that a unified system would be the natural result of systems that demonstrated benefits in terms of economics, ecology and national priorities.

The most encouraging endorsement of the unified system comes on the heels of the Earth Summit this year in Rio. Noel Brown of the United Nations Environmental Program states that tapping remote renewable resources is one of the most important projects to further the cause of environmental protection and sustainable development.

The Author

Peter Meisen received the degree at Applied Mechanics and Engineering Sciences in 1976 from the University of California at San Diego and has been involved in several community activities that focus on food distribution programs in North America. He founded the Global Energy Network Institute in 1986 and established affiliates in the U.S., Canada, Russia, Australia and New Zealand. He has been instrumental in organizing worldwide participation in conferences dealing with intercontinental tie lines for energy interchange.