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Lori Pottinger

Lori Pottinger

Posted: September 26, 2009 05:40 PM

The Wrong Climate for Big Dams in Africa

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Africa is the least electrified place in the world. Some 550 million Africans have no access to electricity.

Not only are they living in the dark; many Africans also have a tenuous water supply. The majority depend directly on rivers and lakes for water. Water stress is growing, creeping across the continent like a swarm of locusts. And climate change (which Africans have had almost no part in creating) is expected to make things dramatically worse. 

Yet many of the continent's energy planners are pinning their hopes for African electrification on something as ephemeral as the rain, by pushing for a grid of large hydro dams across the continent.

Today, the African Union called for a massive system of continental “power pooling” (linking grids across borders), ostensibly to help Africa’s poor.

Elham Ibrahim, the energy chief for the African Union, told Reuters that hydropower is key to power pooling.

But the hydro-pooling plan could leave Africa high and dry. Many existing dams are already suffering from drought-caused power shortages, forcing governments to turn to expensive fossil-fuel emergency plants. New dams are being built with no examination of how climate change will impact them. Past hydrological records, being used as the basis for planning dozens of new large dams, have little bearing on future river flows. The economic impacts of hydro-vulnerability will be felt both in the costs of power cuts on industrial output, and the cost of wasted investments in dry dams. Africa’s poor could become hydropower hostages.

Climate scientists predict truly alarming changes to many African waterways. In his 2006 report, Sir Nicholas Stern predicted that a 3-6 degree Celsius increase in temperature in coming years will result in a 30-50% reduction in water availability in Southern Africa. Scientists recently discovered evidence that droughts in West Africa lasted centuries in the past. Their study suggests global warming could create conditions that favor extreme droughts across much of Western Africa, home to Africa’s biggest reservoir (Akosombo’s Lake Volta), among others. The Nile, Zambezi and other major rivers are also expected to see worse droughts and lower flows.

Africa’s dam promoters insist that by building more dams across a wider region, and connecting them all with transmission systems, odds are it will all work out, and power can be traded to places where drought has crippled the power supply. Yet it’s hard to sell electricity from empty reservoirs.

The World Bank, which is also calling for a resurgence in hydro development in Africa, states that the continent has tapped just 8% of its hydro potential. This is an incomplete message at best. The other side of the coin is that Africa is already dangerously hydro-dependent, with many countries getting most of their electricity (and sometimes all of it) from dams. Meanwhile, Africa has not developed even a tiny fraction of a percent of its available solar, wind, geothermal, or biomass power.

While Africa’s large dams have failed to bring Africans out the dark, decentralized renewable energy projects are well-suited to meeting the needs of far-flung villages and urban areas alike. Diversifying the energy mix is a better bet than gambling on the rain. The palette includes:

Geothermal:  The UN says that Africa has at least 4,000MW of geothermal ready to develop in the East African Rift. but has tapped less than half of a percent of this naturally produced steam-driven power.

Solar: Africa’s potential is nearly limitless. A new study co-sponsored by my organization shows that Mozambique’s huge and virtually unexploited solar potential is about 1.49 million GWh -- thousands of times more than the country’s current annual energy demand. And this power is distributed evenly across the country. Exploiting this energy would benefit the more than 80% of Mozambique’s population that is now off-grid. 

Wind:  Wind potential is also high in many parts of Africa, and is finally beginning to be developed (new large projects are underway in Kenya and Egypt, for example).

Co-gen: The production of electricity from steam, heat, or other energy sources as a by-product of another industrial process is well-suited to many African nations. A new report on Africa's hydropower vulnerability by African researchers estimates that the continent could get 20% of its electricity from co-gen. Mauritius now gets almost half of its electricity from co-gen plants using mostly sugar cane waste.

Diversifying Africa's energy sector would help its climate-adaptation efforts in key ways: it would de-emphasize reliance on erratic rainfall for electricity, reduce conflict over water resources, and protect river-based ecosystems and the many benefits they bring. And it would share the wealth with the half a billion Africans now living in the dark.

 

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