African leap16 May 2013
A swathe of hydro projects – both large and small – are under development or in construction across the middle of Africa. Report by Patrick Reynolds
From coast to coast, across the broad middle of Africa, a full spectrum of hydro development and construction is underway with the sector appearing to be on the verge of a new era.
The wide range of projects is anchored geographically by the massive schemes of the Renaissance project, under construction in Ethiopia, and what would become the world's biggest plant - Grand Inga, in the Demoractic Republic of Congo (DRC) - for which a huge feasibility study is set to report with recommendations very shortly.
Between those geographical extremes, and well below those gargantuan capacity levels, come a swathe of micro, mini, small and simply conventionally big hydro schemes that are being built, planned or proposed. They lie Burundi, Rwanda, Uganda, Zambia, Cameroon, Ghana and there are more in DRC and Ethiopia too. Beyond the middle, hydro activities in Africa also include notable recent schemes in Egypt, such as Merowe, and the almost complete Ingula pumped storage scheme in South Africa.
Greater interconnections between local and national transmission grids are also being needed and being pursued in Africa as elsewhere. Ethiopia is active in this regard also with links in development to Kenya as well as Sudan.
Hydropower development and construction of grid-links are two of the top issues driving the African energy agenda this year, according to the 2013 World Energy Issues Monitor from the World Energy Council (WEC). Published in February, the report adds that the Sub-Saharan African energy leaders who were consulted also add that energy poverty and the energy-water nexus are the other top issues.
With much need for energy and great hydro potential, many non-African players are increasingly active in the middle of the continent, including China and Norway, while Italy has been assisting projects in Ethiopia.
Energy & water issues for Africa
According to WEC's Survey of Energy Resources (the most recently, publicly-released dated in 2010), Africa has almost 3910 TWh/year of gross theoretical capability in hydropower, measured at the end of 2008. Less than half that amount - 1834TWh/year - is estimated to be technically exploitable capability.
There was no estimate given for the economically exploitable capability for hydropower on the continent as a whole. But estimates of economically exploitable capability for some relatively-rich hydro nations were given, and included, across middle Africa, the following: Cameroon (105 TWh/year); DRC (145); Ethiopia (162); Uganda (13); and, Zambia (20).
Upon the release of the 2013 World Energy Issues Monitor, WEC's vice-chair for Africa, Professor Abubakar Sambo, says the continent's resources are immense and 'opportunities are huge'. However, he cautioned, adding: 'But in order to capitalise on these, there needs to be improved regional interconnection and more concentrated efforts across national borders.'
Expanding on these points, Christoph Frei, WEC secretary general, says there are issues of regional interconnection, trade barrier, energy-water nexus and large-scale hydropower development that need tackled, and adds they 'cannot be addressed by any single country alone.'. The study 'clearly shows the imperative for countries to work together in finding a solution,' he concludes.
The points move forward the thinking on the top issues from last year - the first time WEC had assessed African energy leaders' outlook. Then, the prime concerns included energy prices and instability in the Middle East and North Africa. The long-term concern, however, has been energy poverty. Last year, though, renewables and grid interconnections were noted as important too, though receive greater highlighting this time round.
In the section, "Africa's Critical Agenda," the latest report says: "Large-scale hydro and regional interconnection are the issues that are highly uncertain and have seen significant changes recently.
“Large-scale hydro is considered as the most inexpensive, efficient and affordable form of renewable energy, with a large potential yet to develop in Africa (only 7% potential developed - the lowest rate of the world's regions).
“While unceratin, it seems many policymakers and energy experts have voiced the importance of large-scale hydro development, along with taking a realistic approach to forming and developing projects, to build necessary capacity and infrastructure, and to implement them as timely as possible. Otherwise, it would take such a long time before coming onstream, whilst energy demand is catching up much faster than expected leading to a widening gap between supply and demand for electric energy.
“In addition to large-scale hydro, regional interconnection is gaining ground with the development maturity of the five power pools."
Most awaited project in Africa still, having been so for decades, is Grand Inga on the Congo River, in DRC. Within the next few months the debate over costs, benefits and challenges are set to be taken forward into a new chapter upon the immiment completion of the latest feasibility study on the colossal scheme.
In early 2011, a joint venture of EDF and Aecom (through its then recently acquired consultancy RSW International) began work on the feasibility study. The US$13.4 million study for national power utility Societe Nationale d'Electricite (SNEL) has involved examination of the core scheme as well as the necessary transmission links.
Yet while envisioned as potentially having installed capacity approaching 40GW - the biggest hydro power plant ever constructed - the Grand Inga scheme would not be only hydro scheme in the downstream stretch of the Congo, which has immense resources. Two existing plants, built in 1970s-80s, have been undergoing refurbishment and a third is proposed - Inga III, a huge scheme in its own right, at approximately 4.3GW.
Almost 11,800km of transmission lines have been antiicpated as required for the scheme, provided through four connections - two to South Africa and one to each of Nigeria and Egypt, respectively.
The last major presentation and discussion around the hydro potential of Grand Inga was conducted under the auspices of WEC, in 2008. How and what may change following the latest study, from Aecom and EDF (which previously was involved in studies, in 1970s), will be closely watched by all in the global hydro sector for the scale and approach to the realising the potential scheme, but also how the findings and recommendations can take forward a major energy project for Africa.
With eight plants boasting capacities in hundreds of megawatts, most recently the 420MW Gilgel Gibe II and 460MW Beles schemes, Ethiopia is stepping up realisation of its hydropower resources with construction and plans at still larger scale - in gigawatts.
Italian contractor Salini with compatriot consultant Studio Pietrangeli are involved in delivering the 1.87GW (10 x 187MW) Gibe III project for the Ethiopian Electric Power Corp (EEPCO) as well as the huge Renaissance scheme. The client's representative on Gibe III, which involves construction of a 240 m high RCC dam on the Omo River as well as significant underground works, is a joint venture of Electroconsult and Coyne et Bellier. Gibe III is expected to generate 6,500GWh of electricity annually.
The giant scheme in the portfolio, however, is Renaissance. To generate about 15,130GWh of electricity per year, the total capacitiy is 6GW (initially 5.25GW) over two powerhouses. The project was previously named the Millenium scheme, was launched two years ago and will feature Africa's largest dam - a 1.8km long RCC structure under construction on the Blue Nile, and other key features include a gated spillway, and a 5km long by 50m high saddle dam.
Separately, and still in the study stage, are the 2GW Mandaya and 2.1GW Beko Abo schemes on the Blue Nile, and which are to generate 12,100GWh/year and 12,600GWh/year, respectively.
With only micro and small hydro plants domestically, the largest being Rwegura (18MW, 55GWh/year) and Mugere (8MW, 40 GWh/year), Burundi is looking to further development of the tri-national Ruzizi casacade scheme to increase its energy asset base.
Already taking 3MW from the Ruzizi I plant and 13.3MW from Ruzizi II, both under refurbishment, a major increase would come from its share of the Ruzizi III & IV proposed schemes, planned to have total installed capacities of 145MW and 287MW, respectively. The casacade is on the Ruzizi river in the border area with DRC and Rwanda, and Ruzizi III is expected to start construction in the near future, including a 105m long dam and 2.8km headrace tunnel.
The domestic story is not over, though, for while some of Burundi's other hydro plants are very small in capacity the make notable contributions to the country's energy needs. For example, 24.4GWh/year of electricity is generated by the approximately 2.9MW Nyemanga plant - or, a sixth the size of Rwegura giving almost half as much output. The relative ratios for the Ruvyironza plant are similar to Nyemanga, in that only 1.5MW generates 11GWh/year.
Depending on the needs of the mining sector, Burundi estimates its total need for electricity capacity to 2020 lies between 280MW and 1GW, and generated electricity needs to approach 2500GWh/year.
Rwanda's Electricity Development Strategy, 2011-17, calls for hydropower to add 333MW, or a third of the 1GW in total installed capacity the country wants added to its generation base over the period. By this year, small hydro plants will bring almost 21MW of the total into operation.
The country's largest domestic hydro plant will be the 28MW Nyabarongo I project, which the Energy, Water and Sanitation Authority (EWSA) is to commission in 2014. Earlier this year, EWSA issued a call to consultants to undertake a feasibility study for Nyabarongo II which has an estimated capacity in the 12MW-17MW range, a powerhouse with a pair of Kaplan units, and early studies envisaged a 48m high by 228m long concrete gravity dam.
Forthcoming projects include the tri-national Ruziz III & IV schemes from which Rwanda would receive shares of 48MW and 96MW, respectively. Site work on Ruzizi IV )4 x 72MW) is expected to start around 2016-17. Another regional schme in planning is the tri-national 90MW Rusomo Falls project, under development with Burundi and Tanzania for completion by 2017, and from which Rwanda would receive 30MW.
At the mini end of the range, development opportunities also include 9MW comprising 20 projects in four bundles for construction over 2014-15, and 10MW in three bundles to be constructed over 2015-17.
Less than half a year ago the 250MW (5 x 50MW) Bujagali project was officially inugurated and has almost doubled Uganda's effective generation capacity. The project is located on the River Nile, 10km from the outflow of Lake Victoria and downstream of the Nalabaale and Kiira dams.
The US$900 million scheme is one of the largest privately-funded power projects in Sub-Saharan Africa, having been developed Industrial Promotion Services and Sithe Global Power which are, respectively, a unit of the Aga Khan Fund for Economic Development and a majority-owned business of Blackstone Capital Partners.
The partners established Bujagali Energy Ltd to operate and manage the plant. The first of the plant's units became operational just over a year ago and the powerhouse was fully operational by June 2012, less than five years after World Bank approval helps leverage a raft of debt funding to support the developers' equity investments. The project is registered for carbon credits with an avaerage of 900,000 expected to be received annually for sale to boost revenues.
Among the projects in development in Zambia are 750MW Kafue Gorge Lower and 120MW Itezhi-Tezhi schemes. Further projects will include Musonda Falls, Lusiwasi and Chishimba Falls for which site investigation studies are to commence shortly for State-owned Zambia Electricity Supply Corp (Zesco).
A deadline of mid-March has been set for consultants and financial advisers to register interest to work on the Kafue Gorge Lower (5 x 150MW)scheme, which will include construction of a 140m high CFRD dam.
Itezhi-Tezhi (2 x 60MW) is being developed by Itezhi-Tezhi Power Corp, which is a joint veture of Tata and Zesco, and built on a turnkey basis by Chinese group SinoHydro for completion in 2015. Alstom is supplying a pair of Kaplan and generator units. Funding was agreed last year for the scheme, which will constuct a surface powerhouse to exploit an existing dam and reservoir.
Existing key hydro facilities in the country include Victoria Falls, Kariba South and Kafue Gorge in the 1960s and 1970s, respectively - though capacity has been added across the latter two under the Kariba North scheme. In total, Zambia has more than 1.8GW of total generation capacity.
Among the most recent developments in the Malawi/Tanzania area is a development programme launched by their respective governments for the shared Songwe catchment. Lahmeyer is leading a joint venture with ACE Moharram-Bakhoum to undertake the two-year study, which is to develop plans up to tender design stage of an initial phase of the scheme.
The Songwe river basin development scheme has been envisaged to require three dams for multi-purpose benefits, such as flood control, irrigation, water supply and hydro electic generation. The initial phase to be addressed in the study will focus on one dam plus a tunnel, underground powerhouse, irrigation and river stabilisation measures. A joint river basin authority is also to be established.
For Tanzania, Studio Pietrangeli has the 525MW Rumakali scheme in design.
Lahmeyer is also working in Cameroon, on the 450MW Kpep hydro project on the Katsina Ala River which could boost the country's generation capacity by more than 40%. The consultant is undertaking a feasibility study for the scheme following completion of the pre-feasibility study a year ago.
Kpep is being developed by Joule Africa, which has signed a framework agreement with the Ministry for Water and Energy to have the project implemented by 2018. Seperately Lahmeyer has been working with Joule Africa in Sierra Leone, on the Bumbuna scheme which is being expanded.
Hydro-rich Cameroon has only approximately 720MW of installed hydropower capacity, equating to about three-quarters of the total generation portfolio of the country. It plans to triple the total asset base to 3GW by 2020, but even then its hydro resources have been estimated at 12GW - half of which is in the Sanaga basin, where the possibility of cascade development is being examined. A year ago the World Bank approved a loan to help fund the 30MW Lom Panger scheme, which would also help to boost year-round production at the Edea and Song Loulou plants.
Approaching completion in Ghana is the 400MW (3 x 133MW) Bui project, which is being developed by Bui Power Authority. Impoundment of the reservoir at Bui Gorge on the Black Volta River commenced in 2011. The plant's Francis units are set to come online in stages this year, and the station is estimated to generate net average output of almost 970GWh/year in the long-term.
Key features of the project include: a 108m high by 492.5m long RCC dam; a five-gated spillway designed to pass a 10,000-year return period flood of 10,450m3/s; two saddle dams; a powerhouse for three Francis turbines; and, four transmission lines totalling 244km in length.
Preparatory works and river diversion took place over 2007-8, and dam construction got underway in late 2009. SinoHydro, which is also working on the Itezhi-Tezhi scheme in Zambia, has executed the turnkey contract. Engineering consultant is Coyne et Bellier.
Africa's colossal anchor schemes will deliver a new, heightened presence in the global hydro energy sector following the completion of Renaisance and as more steps are taken to tap the vast potential of the Congo River.
But the burning spotlights on these monumental undertakings should not put into shade the many other smaller projects being constructed or to come, spread wide and far across the middle of Africa.