About 365 giant wind turbines are to be installed in the desert around Lake Turkana in northern Kenya -- used as a backdrop for the film The Constant Gardener -- creating the biggest wind farm on the continent. When complete in 2012, the £533-million (R6,9-billion) project will have a capacity of 300MW, a quarter of Kenya's current installed power and one of the highest proportions of wind energy to be fed into a national grid anywhere in the world.
Until now only North African countries such as Morocco and Egypt have harnessed wind power for commercial purposes on any real scale on the continent. But projects are beginning to bloom south of the Sahara as governments realise that harnessing wind potential can meet a surging demand for electricity and end blackouts.
Ethiopia has commissioned a £190-million, 120MW farm in the Tigray region, representing 15% of its current electricity capacity, and intends to build several more. Tanzania has announced plans to generate at least 100MW of power from two projects in the Singida region, more than 10% of the country's current supply.
In March South Africa, whose heavy reliance on coal makes its electricity the second most greenhouse-gas intensive in the world, became the first African country to announce a feed-in tariff for wind power, whereby customers generating electricity receive a cash payment for selling power to the grid.
Kenya is trying to lead the way. Besides the Turkana project, which is being backed by the African Development Bank, private investors have proposed establishing a second wind farm near Naivasha. In the Ngong hills near Nairobi-Masai herders and elite long-distance athletes used to braving the frigid winds along the escarpment already have towering company: six 50m turbines from the Danish company Vestas were installed last month and will add 5.1MW to the national grid from August. Another dozen turbines will be added at the site in the next few years.
Christopher Maende, an engineer from the Kenyan state power company, KenGen, which is running the Ngong farm and testing 14 other wind sites across the country, said local residents and herders were worried that noise from the turbines would scare their animals. "Now they are coming to admire the beauty of these machines," he said.
Kenya's electricity is already very green by global standards. Nearly 75% of KenGen's installed capacity comes from hydropower and a further 11% from geothermal plants, which tap into hot rocks beneath the Rift Valley.
But fewer than one in five Kenyans has access to electricity although demand is rising quickly, particularly in rural areas and from businesses. At the same time, increasingly erratic rainfall patterns and the destruction of water catchment areas have affected hydroelectricity output. Low water levels caused the country's largest hydropower dam to be shut down last month.
As a short-term measure, KenGen is relying on imported fossil fuels, such as coal and diesel. But within five years the government wants to reduce drastically the reliance on hydropower by adding 500MW of geothermal power and 800MW of wind energy to the grid.
Not only are they far greener options than coal or diesel, but the country's favourable geology and meteorology also make them cheaper alternatives over time.
The possibility of selling carbon credits to companies in the industrialised world is an added financial advantage.
"Kenya's natural fuel should come from the wind, hot underground rock and the sun, whose potential has barely even been considered," said Nick Nuttall, a spokesperson for the United Nations Environment Programme. "After the initial capital costs, this energy is free."
The Dutch consortium behind the Lake Turkana Wind Power (LTWP) project has leased 66000ha of land on the eastern edge of the world's largest permanent desert lake. The volcanic soil is scoured by hot winds that blow consistently year-round through the channel between the Kenyan and Ethiopian highlands.
According to LTWP, which has an agreement to sell its electricity to the Kenya Power & Lighting Company, the average wind speed is 11m per second, akin to "proven reserves" in the oil sector, said Carlo van Wageningen, the chairperson of the company. "We believe that this site is one of the best in the world for wind," he said.
If the project succeeds, the company estimates that there is the potential for the farm to generate a further 2700MW of power, some of which could be exported.
But there are major logistical obstacles to overcome.
The remote site of Loiyangalani is nearly 480km north of Nairobi. Transporting the turbines will require several thousand truck journeys, as well as the improvement of bridges and roads along the way. Security is also an issue, as the region is bandit country and many locals are armed with AK-47 rifles.
LTWP also has to construct a transmission line and substations to connect the wind farm power to the national grid.
It has promised to provide electricity to the closest local towns, now powered by generators.
Green power for Africa
At the end of 2008 Africa's installed wind power capacity was only 593MW. But that is set to change fast.
Egypt has declared plans to have 7200MW of wind electricity by 2020, meeting 12% of its energy needs. Morocco has a 15% target over the same period. South Africa and Kenya have not announced such long-term goals, but with power shortages and wind potential of up to 60 000MW and 30 000MW respectively, local projects are expected to boom.
With the carbon-credit market proving strong incentives for investment, other types of renewable energy are also set to take off. Kenya is planning to expand its geothermal capacity and neighbouring Rift Valley countries are examining their own potential.
As technology improves and costs fall, solar power will also enter the mix. Germany has already publicised plans to develop a R23.6-trillion solar park in the Sahara. "Ultimately for Africa solar is the answer," said Herman Oelsner, the president of the African Wind Energy Association. --©Guardian News & Media 2009
ABB building a model for energy efficiency
South Africa's new green building in Johannesburg showcases energy-efficiency technologies that mitigate environmental effects yet ensure lower operating costs.
The company's headquarters, factory and logistics centre are located on a 96 000m2 site at Longmeadow, near Modderfontein.
Built at a cost of R400-million by ABB and the developer, Improvon, the building incorporates the latest environmental concepts and technology.
It will be the venue for the group's global customer event, ABB Automation and Power World 2009, which will be held for the first time in South Africa from November 11 to 12.
The Longmeadow building features many green-building elements.
The cost-effective, energy-efficient technologies, many of which have been developed by ABB, include a building automation system, power factor correction, drives and high-efficiency motors for the heating, ventilation and cooling systems.
Every work station is fitted with a photosensitive switch that turns on low-energy lights whenever people arrive and turns them off whenever they leave their desks.
Insulation in the walls, roof and floor will help reduce cooling costs up to 8% in summer and heating costs up to 30% in winter.
Composite pipes reduce energy consumption as they have low conductance, reducing heat loss and gain.
By insulating the building and through the various energy-efficiency measures used, the electricity consumption of the building has been reduced from 120Wm2 on average for commercial buildings to about 60Wm2, says Joe Kilian, consulting electrical engineer.
The collection system on the roof of the building automatically diverts rainwater into two ponds and then into tanks from where it can be used to water gardens and top up water features.
A grey-water recycling system reduces water consumption, as do the landscaped gardens, which feature indigenous plants and trees.
The solar heating system on the roof heats water delivered to the showers. This natural free-energy source replaces electrical heating and does not produce carbon emissions.
Energy consumption for the building's heating system is also reduced with a heat-reclaim pump system that captures hot air from the air-conditioning system and diverts it to supplement the building's boilers.
The building's H-shaped architectural structure lowers energy consumption as all office work stations are on the edges of the building where there is an ample supply of natural light.
ABB has also adopted a green IT approach with the focus on infrastructure to drive flexibility and efficiency.
Source : Mail & Guardian, 08/09
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