8 July 1995    No 1985     Weekly £1.70

New Scientist:
GLOBAL POWER — The electric hypergrid

THE INTERNATIONAL GRID

WHEN Arab energy ministers met in Cairo in April, there was one thing at the top of their agenda-plans for a regional electricity grid that would stretch more than 5000 kilometres from Morocco in the west to the Gulf states in the east. And for Maher Abaza, Egypt's energy minister and the meeting's host, that would only be the start. Abaza foresees a network, with Egypt at its heart, that would give the energy-hungry countries of Europe access to the hydropower of Africa's mightiest rivers. Ultimately, he envisages a worldwide power system that would cut the cost of electricity everywhere. This, says Abaza, represents "the hope for the peoples of the developing world". Abaza is following in the footsteps of Richard Buckminster Fuller, the maverick American architect and futurologist who was born 100 years ago next week. Buckminster Fuller is remembered chiefly for his geodesic domes, but he also dreamt of continents linked by high-voltage pylons and undersea cables. In the mid-1970s he predicted that the world would one day have a global electricity grid. Now engineers are planning the links that could eventually grow into an international network, distributing power from the rainforests of Borneo and the geothermal rocks of Iceland, the Zaire river and France's nuclear power plants.

Dreams of a global electricity grid are close to reality. Fred Pearce looks ahead to a world in which electrical power is traded worldwide

In Anchorage, Alaska, the talk is of a project to bring hydroelectricity from Siberia to North America through a submarine power line. The Bering Strait, which separates Russia and Alaska is only 85 kilometres wide and 50 metres deep, but the cable could cost some $2 billion to lay. "We've put eight years' work into engineering, geological and environmental studies," says George Koumal, chairman of the Interhemispheric Bering Strait Tunnel Group, which wants to combine the power link with a railway tunnel. Now he is looking for finance and, in September, comes to London for a fund-raising conference. Last November, plans were revived to harness up to 37 000 megawatts of generating capacity on the Mekong river, which runs for more than 4000 kilometres from China, through Burma, Laos, Thailand, Cambodia and Vietnam. Power lines already straddle the river, linking the site of the Nam Ngum dam, near Vientiane, to the Thai border, and construction began this year on another, much larger "export dam" in Laos on the Nam Theun river, a tributary of the Mekong. "It is our hope to build a power grid in the region that will allow the six countries to utilise power most efficiently," says Noritada Morita, director of the Asian Development Bank, which is contributing funds. The Mekong links may lead to a larger southeast Asian grid. Malaysia and Thailand, two of the world's fastest-growing economies, are planning cross-border power connections. And, next year, Malaysia is due to begin building a giant hydroelectric plant at Bakun on the Balui river in the rainforest of Sarawak on the island of Borneo. The power station, capable of generating 2400 megawatts, will supply electricity to the mainland through a 650-kilometre cable on the bottom of the South China Sea. Any power that Malaysia does not need will go to Brunei or the Indonesian state of Kalimantan, which between them occupy the rest of Borneo, or to Singapore, says the Malaysian government.

The Himalayan kingdom of Nepal is another remote region with a large hydroelectric potential. It currently has the lowest per-capita energy consumption of any nation on Earth the capacity of the national system is just 278 megawatts but, according to its Water and Energy Commission, could generate more than 40 000 megawatts of hydroelectricity in its steep valleys. The Arun III hydroelectric project, the first of three dams on the Arun river, which will generate 1500 megawatts, is about to receive funding from the World Bank. This is likely to be followed by another, generating 11 000 megawatts and costing $6 billion, in the Chisapani Gorge just 45 kilometres from the Indian border. And Nepal has plans for more than ten other schemes.

Himalayan potential

Nepal is about to build the long distance power lines to transport the electricity these schemes will generate. Its first customers will be the great industrial cities of northern India, a region of 300 million people where rapid industrial development has led to frequent power cuts. Indian planners are also eyeing Nepal s Himalayan neighbour, Bhutan, which has an estimated potential for generating 20000 megawatts of hydroelectric power.

But at present, the world's largest exporter of electricity is Paraguay. The Itaipu dam on the River Parana is the world's biggest power complex with a capacity of 12 600 megawatts from where power is fed to Rio de Janeiro and Sao Paulo in Brazil.

Such vast projects appall many environmentalists, who point to the ecological damage they can cause. But not all US Vice-President Al Gore, who is noted for his environmental concerns, says: "A global energy network makes enormous sense it we are to meet global energy needs with a minimal impact on the world's environment."

Intercontinental electricity grids are the only way to harness the planets great sources of renewable energy and link them to centres of population according to Peter Meisen of Global Energy Network Institute in San Diego this nonprofit-making organisation is dedicated to promoting Buckminster Fuller's vision of a global grid. "Modern transmission lines can efficiently span up to 6000 kilometres, says Meisen. This is enough to bring power to large industrial centres from hydroelectric sites on the great Arctic rivers, such as the Ob and Yukon, Mackenzie and Lena and tidal power sites in Argentina, China, Australia and India. A global grid could also tap solar power right round the tropics and the geothermal potential of the "ring of fire" round the Pacific Ocean, in Iceland and in the Rift Valley of Africa.

Modern society is founded on electricity, in 1990, the world's power stations pumped out enough power for every person on the planet to run four 60-watt bulbs permanently. And production is growing fast. Output was up 134 per cent from 1970 to 1990, while the global population rose by just 40 per cent. That puts electricity well ahead of cars (up 124 per cent in the same time), cigarettes (75 per cent) or oil (41 per cent).

More investment now goes into distributing electricity than generating it, and lines of pylons are extending round the world faster than roads. Four billion people, or around two-thirds of the world's population, are connected to distribution networks, Many began as local enterprises, but more and more have become international, so that today more than 50 nations have electrical interconnections with their neighbours.

Such links can be complex. All grids run on alternating current, but the frequencies and other specifications often differ from country to country, so giant transformers have to be installed at borders, These usually convert AC power from one country into direct current and then back into AC to meet its neighbour's specification. This is expensive. A link from Germany to the Czech Republic, completed in 1993, cost $180 million.

International links allow countries to share their generating capacity, and smooth out surges in demand. These can occur at various times of day: during the morning switch-on of factories, or the evening rush for the kettle at the end of a popular TV programme, for example. A link can reduce the number of power stations both partners need to build to cope with these peaks. Take the submarine cable linking Britain and France, which came into service in 1986. In England and Wales, average winter demand is 38 000 megawatts, but at peak times the load rises to 47 500 megawatts. France can help out because it has spare generating capacity and its peak load comes at different times from Britain's.

Mix and match

Different types of power station have different capabilities, and international links can help here too. Nuclear power stations can take several days to switch on or off, so they are best at providing continuous, "base-load" electricity, A hydropower generator can be started in seconds, making it ideal for meeting surges. Switzerland imports base-load electricity from French nuclear power plants, but exports power from its Alpine dams in short bursts to meet France's peak-load needs.

Long-distance power lines may also allow several countries to benefit from a remote source of cheap power. The world's ten largest power stations are all hydroelectric plants, and most of them are far from their markets. Four are in Siberia three in remote regions of South America and two in northern Canada.

The Achilles heel of pylon links is their vulnerability in wartime. The classic example is Mozambique's hydroelectric dam on the River Zambezi at Cabora Bassa, which was completed in 1976. Built to fuel the gold mines of South Africa 1300 kilometres away, it is capable of delivering 4000 megawatts of electricity more than ten times Mozambique's domestic demand. During two decades of civil war in Mozambique, the pylon link was regularly cut by antigovernment guerrillas. Only now, two decades on, can the dam do the job it was designed for.

But power links can be a force for Peace. Following the Israel-Jordan peace pact last October, the two states plan to join their grids. A World Bank study last year spelt out the advantages. "As Israel and Jordan have sharply different daily and weekly load peaking patterns, interconnection of their national grids would permit mutually profitable trading between power utilities, and reduce the need for costly back-up capacity for each country, the report concluded.

The Bank also proposed connecting Israel to the Jordan-Egypt link now being built under the Red Sea, and a large hydroelectric project for the rift valley between the Red Sea and Dead Sea, the lowest-lying lake in the world. The scheme would exploit the 400-metre level difference between the two seas by building a canal between them and a hydroelectric power plant on the shores of the Dead Sea. The power station would spur industrial development in the region, and power a desalination works that would supply water to farms and resorts.

During the l950s, the colonial powers in Africa created several international dams. Besides Mozambique's Cabora Bassa dam, built by the Portuguese, the Kariba dam on the Zambezi has, since its construction in the 1950s, been the mainstay of the interconnected Zambian and Zimbabwean electricity grids. And Ghana's Akosombo dam, conceived by the British and executed shortly after independence, exports power to neighbouring Togo and Benin.

But some more recent schemes have collapsed because of lack of funds. The Manantali dam on the upper reaches of the Senegal river in the West African state of Mali was completed in 1987. It was intended partly to generate power for Dakar, the capital of Senegal more than 1000 kilometres away on the Atlantic coast. Rut the money ran out and, almost a decade on, the gaps left in the dam for the turbines remain empty and the pylon route to Dakar is no more than a line on the map.

The densest network of links is in Europe. The countries of mainland Western Europe own 14 per cent of the world's electricity generating capacity and, for around 50 years, they have been joined by a system of AC links known as the Union for the Cooperation of Production and Transmission of Electricity. The system is connected by DC links to a Scandinavian grid via Denmark, and to Britain by the Channel link.

Czech mate

There is a similar network in Eastern Europe, and a growing number of links between the two. They were being built even before the Berlin Wall fell In thc 1980s, Czechoslovak dams began supplying power to Germany and Austria which also established pylon links with Hungary and the former Yugoslavia. In mid-1993, the capacity of the direct connections between West and East Europe was doubled with the completion by the German and Czech governments of a DC link near Weiden in Bavaria.

The East European and Scandinavian grids are both connected to the United Power System, which cove s the former Soviet Union and taps Siberia S giant hydroelectric plants. Until 1989 the UPS was a major exporter of power to Eastern Europe. Since then industrial decline has reduced the trade.

But within Europe, international trade in electrical power is rising fast. During the 198Os, when the amount of power generated increased by half, the trade in electricity doubled, Austria, France and Switzerland export more than 10 per cent of their production, while Finland, Italy and Portugal import more than 10 per cent of their requirements. Germany exports power during off-peak hours, but is 1an importer during peak periods, especially in summer.

Sea links

The sea is only a minor obstacle to European grid-builders. The cross-Channel link is 50-kilometres long, and Norway and Denmark are joined by a 125-kilometre submarine cable across the Skagerrak. The world's longest submarine link stretches for 200 kilometres along the bottom of the Gulf of Bothnia, linking Finland and Sweden. Two years ago, Icelandic engineers proposed laying a 1000-kilometre cable beneath the North Atlantic to Scotland, to allow the island to exploit its hydroelectric and geothermal potential by selling electricity to Britain and continental Europe.

In North America, there are two prime grids, both cross-border, covering the east and west of the US and Canada. Power from Quebec's hydroelectric plants around James Bay, with a combined capacity of 15 000 megawatts, is brought south on five high energy power lines into the northeastern US. The link provides a tenth of New York City's power. Opposition from Cree Indians, whose land was to be flooded, recently halted Hydro-Quebec's plans to double the capacity of the James Bay complex. "We regard this as a temporary setback," the giant state enterprise says.

Such regional networks could be the potential building blocks of a global grid. Besides the Alaska link, Russian engineers want to export power from their Siberian dams to the industrial centres of China, Japan and Korea, the top priority being a Russia-China link. The two countries plan a cascade of clams on the Amur river in Manchuria, where it forms the border between them, before cutting across Russian territory and into the Pacific Ocean.

While the superpowers shape up for electrical union, the developing world is looking to transnational electricity grids to promote economic development. In 1993, the African Development Bank agreed to pay for a feasibility study into erecting a 4000-kilometre power line from Zaire to Egypt, passing through the Central African Republic, Chad and Sudan. The idea is to turn the Zaire, the second largest river in the world, into a power source for much of northern Africa.

Black power

The river could provide up to 20 000 megawatts of electricity from one site, the Inga Falls, between Kinshasa and the Atlantic Ocean. There is already a hydro power station at the falls which sends electricity south to copper mines in southern Zaire and Zambia. Twenty years ago, South Africa proposed expanding its capacity to create more power for southern Africa, where power lines already link South Africa, Zimbabwe, Botswana, Namibia, Lesotho, Swaziland and Mozambique. Northern Africa need not worry, though. The Inga Falls could, in theory, supply more than twice the current electricity demand of the whole continent.

The idea of a single site powering the whole of Africa may be absurd, But as electricity demand across the planet grows, the case for ever larger regional electricity grids becomes stronger. "In future," says Meisen, "it will be possible to meet Buckminster Fuller's vision of interconnecting continents A global electricity grid is too large a project to be built as a single endeavour. But, like the emerging worldwide grid of transcontinental highways it could happen nonetheless.

---