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Why Africa should shun hydropower mega projectsAfrica is the least electrified place in the world. An estimated 550 million Africans have no access to electricity. Nearly half of African countries have a power crisis. Solving this huge problem is made more difficult by widespread poverty, and because most Africans live far from the grid, greatly adding to the cost of bringing electricity to them.
Under these challenging conditions, there are no second chances for electrifying Africa: it must be done right the first time. 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.
The World Bank has joined the fray, with its latest World Development Report calling for a major hydropower rollout for the continent.
The failure of this vision lies in the unpredictable nature of Africa’s rivers, a situation that will be made worse by a changing climate. New African dams are being built with no examination of how climate change will impact them. Many existing dams already are suffering from drought-caused power shortages.
Climate change is expected to alter the hydrology of African rivers dramatically, creating both worse droughts and more dangerous floods (the latter causing safety concerns for poorly maintained or operated dams).
At the same time, many African nations face huge water security problems.
In this climate, the proposed frenzy of African dam building could be literally disastrous.
The oft-repeated sound bite that only 5%-8% of the continent’s hydro potential has been tapped is an incomplete message at best. The other side of the coin is that Africa is already dangerously hydro-dependent.
Meanwhile, Africa has not developed even a tiny fraction of a percent of its available solar, wind, geothermal or biomass power.
While large dams have done little to bridge the ‘electricity divide’ that has left so many Africans in the dark, renewable energy projects can be scaled to meet the needs of the average African village (or, for that matter, urban area).
At a time when global warming threatens to make Africa’s rivers even less reliable for large hydro projects, and their waters more precious for other uses, donors and governments should be looking to diversify the energy mix.
Risky rivers
Past hydrological records, upon which dozens of new large dams are being planned, unfortunately have little bearing on future hydrology. The economic impacts of hydro vulnerability will be felt both in the costs of power cuts upon industrial output, and the cost of wasted investments in non-performing dams.
The economic risks of unviable dams will compound the risk already being taken by so many African nations: that of over-dependency on hydropower to supply electricity. Already, the majority of sub-Saharan states get most of their electricity from rivers. (At least two nations have begun to reverse this dependency: Tanzania, which is now developing its gas fields; and Kenya, which has become an African leader in geothermal power.)
The other climate risk is that many large dams seriously harm downstream riverine communities and ecosystems, which is likely to make climate adaptation that much harder for the many millions of Africans who depend directly on rivers and lakes for their livelihoods, food and water supply.
Like the fairy tale that warns of “killing the goose that lays the golden egg”, African dam planners are putting at risk irreplaceable ‘golden egg’ resources such as clean, abundant water supply, agriculturally important sediments that replenish floodplains, riverine forests and fisheries.
Some dam planners agree that African hydroelectric schemes may be plagued by variable rainfall patterns, but believe that they can ‘play the odds’ and simply build more dams, across a wider region, and connect them all with transmission systems that would allow power to be traded to places where drought has crippled the power supply. Yet, it is difficult to sell electricity from empty reservoirs.
Climate scientists predict truly alarming changes to various African waterways. United Kingdom government researcher Sir Nicholas Stern recently predicted that a three- to six-degree Celsius increase in temperature in the next few years will result in a 30% to 50% reduction in water availability in southern Africa.
Scientists have discovered evidence that droughts in West Africa lasted centuries in the past. Their 2009 study suggests global warming could create conditions that favour extreme droughts across much of western Africa, home to Africa’s largest reservoir (Lake Volta Akosombo), among others. East Africa has been drying since the mid-1980s, a trend that is already shaving percentage points off gross domestic product for the region’s states.
A new report, “Large Scale Hydropower, Renewable Energy and Adaptation to Climate Change” by AFREPREN states, “Kenya’s GDP is equivalent to US$29.5 billion; the estimated loss during the aforementioned drought-induced power crisis was about 1.45% of GDP. This translates to US$442 million lost, which could have been used to install 295MW of new renewable power capacity.”
Most of the Nile Basin states get more than 70% of their electricity from hydro. The Intergovernmental Panel on Climate Change notes that there already has been “a reduction in runoff of 20% between 1972 and 1987” in the Nile, and “significant interruptions in hydropower generation as a result of severe droughts.”
Even though some parts of Africa are expected to receive more rain, that increase is expected to be overwhelmed by an increase in temperature across the continent, which will lead to higher evaporation rates.
A 2006 study by climate experts at the University of Cape Town revealed that even a small decrease in Africa’s rainfall could drastically reduce river flows, affecting a quarter of the continent. For example, a 10% reduction in rain over the Johannesburg area could lead to a 70% drop in the Orange River’s levels. In parts of northern Africa, river water levels would drop more than 50%. “It’s like erasing large sections of the rivers from the map,’’ said Maarten de Wit, who headed up the study.
Leading by bad example
Ethiopia is fast becoming Africa’s poster child for bad dam development. Not only is the Ethiopian economy on track to become a ‘hydrological hostage’ due to its almost complete reliance on high-risk hydropower (85% now, jumping to 95% with its current slate of dams); its master energy plan calls for $3 billion in new investments, most in new big dams.
It has just completed Africa’s tallest dam, Tekeze, the costs of which have skyrocketed and the output and life expectancy of which is premused to be greatly diminished by the river’s high silt load.
One engineer on the project told us anonymously that he had never in his dam-building career seen so much sediment load in a river.
Ethiopia’s next big project, Gibe 3 on the Omo River, is the most poorly planned major hydropower project being built on the continent today. The government has cut corners in its preparation, increasing its risks of economic and technical failure, and has done next to nothing to reduce the project’s massive ecological and social footprint.
The dam will change forever the Lower Omo River Valley, homeland of half a million farmers, herders and fishermen.
The dam will affect ecosystems and disrupt communities all the way to the world’s largest desert lake, Turkana, downstream in Kenya. An oasis of biodiversity in a harsh desert, Lake Turkana, a World Heritage Site, supports more than a quarter of a million Kenyans and rich animal life.
The Omo River accounts for 80%-90% of the lake’s inflow. That will be curtailed by half as the dam fills, and reduced thereafter by evaporation from the massive reservoir.
Turkana’s salinity – already high – will intensify, making it undrinkable and affecting fisheries.
Such outcomes should have been predicted in project analysis, but Ethiopia began construction before proper studies were done.
Ethiopian government officials told the BBC that proper environmental studies were simply “luxurious preconditions”.
Currently, some four million Kenyans depend on food aid in the current drought. Ethiopia has had five major droughts since 1980.
In 2003, Ethiopia’s power supply was held hostage by severe drought, forcing sudden and severe power cuts that lasted six months, and costing $200m in annual productivity. A drought-crippled Gibe 3 would bring a sea of red ink to Ethiopia and lead to blackouts and economic consequences for regional governments that buy its electricity.
Energy insurance
African nations have many better alternatives to large-scale hydro. A few examples:
• Geothermal: As the United Nations notes, Africa has an abundance of geothermal potential. Says Achim Steiner, UN Under Secretary-General and UNEP executive director, “There are least 4 000MW of electricity ready for harvesting along the Rift. It is time to take this technology off the back burner in order to power livelihoods, fuel development and reduce dependence on polluting and unpredictable fossil fuels. From the place where humankind took its first faltering steps is emerging one of the answers to its continued survival on this planet.” UN figures show that Africa has tapped less than 0.6% of its geothermal. Kenya is the exception, with 10% of its electricity now coming from geothermal.
• Solar: Africa’s potential is nearly limitless. A new study 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. The report also reveals that South Africa, the main client for the bulk of the electricity from the planned Mphanda Nkuwa Dam, could quickly save three to five times the amount of Mozambique’s entire electricity consumption.
• Wind: Wind potential is also high in many parts of Africa, and is finally beginning to be developed (new large projects are under way in Kenya and Egypt).
• Co-generation: The production of electricity from steam, heat or other energy sources as a byproduct of another industrial process is well suited to many African nations. AFREPREN estimates that Africa 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-emphasise 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.
