Hydropower

The potential of small hydropower plants in South Africa

Kendal Power station is one of Eskom’s coal-fired power stations in Mpumalanga. In recent times, ‘cleaner’ energies have stepped into the limelight as alternatives to meet rapidly growing demands for power. Graeme Williams/www.mediaclubsouthafrica.co.za Graeme

Renewable energy in the form of hydropower Plan for the period 2010 to 2030 calls Small hydropower in has been cited as one sustainable way for for the deployment of 17 800 MW of South Africa energy from renewable sources. South Africa to meet its future power needs. For some, SSHP specifically holds ommissioned in 1895, Cape Petro Kotzé reports. certain promise even though its CTown Municipality’s first power contribution to the mentioned White station, and the country’s first hydro- enewable energy is the Paper’s target is estimated to amount electric station was supplied with proverbial Cinderella of to only 10%. Roughly defined as water from the Woodhead Reservoir the energy sector. Over­ systems that generate 10 MW and on Table Mountain. With two shadowedR by coal and other fossil less power, it is often subdivided 150 kW generators commissioned fuels, the possibilities of ‘cleaner’ into pico (generating up to 20 kW), on the banks of the Molteno River, energies have stepped into the micro (between 20 kW to 100 kW) the dynamos of the Graaff Electric limelight as alternatives to meet and mini (100 kw to 1 MW range). Lighting Works at Molteno reservoir rapidly growing demands for power. It is tagged as a possible solution in Oranjezicht could be driven either Locally, South Africa’s ratification to some of the major challenges of by steam or water power. By June of the Kyoto Protocol and govern­ the African energy solution, like 1896, the plant was run by water­ ment’s approval of the White Paper rural electrification and additional power for 2 590 hours and by steam on Renewable energy in November capacity for national and local grids. for 691 hours. 2003 pushed renewable energy to Furthermore, SSHPs produce mini­ Two 6 kW hydroelectric genera­ the forefront. In the latter, a commit­ mal quantities of carbon and other tors were also in use at the Pilgrim’s ment was made to generate 10 000 emissions during construction and Rest gold mines in 1892, upgraded GWh of power from renewable operating life, while it is entirely to 45 kW in 1894. In 1896, a hydro sources such as biomass, wind, solar, non-consumptive of water. In reality, generating station was built at radiation and small-scale hydro­ even though it never reached massive Brown’s Hill using two Escher Wyss power (SSHP) by 2013. Furthermore, dissemination, South Africa already Girrard impulse turbines coupled to South Africa’s Integrated Resource has a long history with SSHPs. Siemens 160 kW alternators. Jubilee

18 The Water Wheel November/December 2011 Hydropower

Power Station was built downstream According to the mentioned More unconventional, mostly and an Escher Wyss Francis turbine baseline study, there is still significant untapped potential includes South and a Siemens 150 kVA alterna­ potential for SSHP development in Africa’s inter-basin transfer schemes, tor were installed. These sets were South Africa, particularly in the East­ where SSHPs can be installed at loca­ among the first three-phase alterna­ ern Cape and KwaZulu-Natal. Barta tions where a gravity water supply tors installed in the country and maintains that South Africa’s lack of scheme component is present. Suita­ were used to power the first electric water resources should not neces­ ble sites identified in Barta’s updated railway (excluding demonstration sarily be seen as detrimental for this 2010 feasibility report include the prototypes on the Witwatersrand purpose. This is because hydropower Breede/Berg, Lesotho Highlands in 1892). The railway transported can be derived not only from con­ Water Project, the Orange/Modder, ore to the reduction works over a ventional sources, like rivers but also Vaal/Crocodile, Thukela/Vaal and, 12 mile length of track using two through more unconventional means; ‘most promising’, the Orange/Fish 19 kW locomotives. including tapping hydropower from Water Transfer Scheme. However, Bo Barta, author of the 2002 existing infrastructures. many systems including irrigation Baseline study on hydropower canals, environmental water releases in South Africa (compiled for the Small hydro potential (from large and medium dams) and Department of Energy) adds that bulk water supply pipelines can also SSHP power generation also played onventional small hydropower be utilised, as the potential to gener­ a significant role in the electrifi­ Cinstallations (run-of-river) often ate power in these systems are cur­ cation of urban settlements situ­ involve the construction of a weir and rently going to waste. ated along the eastern side of the a simple intake structure with water Rand Water, for example, intends Drakens­berg Mountain range. He transferred by a conduit or canal to to install four SSHPs within their says that most of the SSHPs fell into a suitable point. Here it is dropped hydraulic network. According to disrepair after the establishment through a penstock to the turbine or Rand Water Senior Mechanical Engi­ of the Electricity Supply Commis­ generator. Also referred to as ‘green­ neer Iveen Mbhele, the water sup­ sion (now Eskom) in 1923 and field’ hydropower sites, it typically ply to turbines will be tapped from the national grid. “Eskom could needs to be situated on rivers with the existing water supply pipelines produce sustainable, bulk energy relatively constant flow and a suitable and fed back to the pipelines. These for relatively cheap,” says Barta, water drop, and is mostly suitable for are currently at tender stage for “and the small schemes, which were mini and pico hydropower sites. the supply and installation of four relatively seasonal and unsustain­ Barta estimates that there is also hydropower plants, of which com­ able couldn’t compete.” As a result potential to blow life back into some missioning is expected to take place people started to switch from hydro of the existing SSHP installations in 2014/2015. The combined capac­ to coal-based electricity. scattered around the country, most ity of the four plants will not be more Today there are still a number notably at Belvedere (2 MW), Ceres than 16 MW and will be fed into the of SSHPs in operation, like the (0,8 MW), Clanwilliam (1 MW), national power grid, although the 2 MW Friedenheim Hydro sup­ Kouga (5,3 MW), Ncora (2,4 MW) main aim is to offset Rand Water’s plying electricity to Nelspruit since and Pongolapoort (2,7 MW) and “a high energy bill, Mbhele says. He 1988 and the 0,8 MW Baken­kop few other smaller privately-owned adds that the four sites are at Zoek­ Hydro at Piet Retief (still in working installations”. fontein (about 8 km from Vaal order after more than 50 years). In total (excluding mines) there is an estimate 42 MW of power supplied by SSHPs in the country. Notable is Bethlehem Hydro, the first hydro­ power plant to be commissioned in South Africa since 1988. The 7 MW operation entails two plants, a 3 MW operation on the wall of the Sol Plaatje Dam, and a 4 MW run-of-river plant at Merino. It is managed by Independent Power Producer (IPP) NuPlanet and sells its electrical power and capacity under Bethlehem Hydro’s 3 MW operation on a long-term power purchase agree­ the wall of the Sol ment (PPA). NuPlanet Plaatje Dam.

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Dam), Klipfontein (Kempton Park with these, along with sugarcane opportunities, and be a huge finan­ area), Brakfontein (Midrand area) bagasse (the fibre that comes from cial injection into the sector. and Hartebeeshoek (Roslyn area), crushing the sugar cane) for cogen­ The DoE has put out a tender for but there are more sites that will be eration, landfill gas extraction and the procurement of the first 3 725 explored in future. commercial and domestic solar MW of renewable capacity by 2016, For power giant Eskom, which water heaters. The DoE also estab­ which is likely to attract local and has a total net capacity of almost lished the Renewable Energy Finance international investment of between 41 000 MW, but still needs to provide and Subsidy Office (REFSO), whose US$10 billion and US$12 billion. for South Africa’s demand for power mandate includes the management Potential bidders for the supply – expected to double by 2030 from of renewable energy subsidies, offer­ of the first 3 725 MW of renew­ present levels of around 37 000 MW, ing advice to developers and other able power, including onshore, SSHPs might not be the answer. The stakeholders. concentrated solar, biomass and potential can, however, be untapped Regardless of government initia­ small hydro, had until 4 November by IPPs. According to Doug Kuni, tives, few small hydropower develop­ to submit their bids for considera­ Independent Power Producers’ MD, ments are taking place. Kuni says tion. The preferred bidders were to IPPs are designed to be quick and that the challenges that IPPs face are be announced at the UN climate nimble, and can be viable solution “extreme” and largely structural and summit in Durban in November. for power supply in a power-short regulatory as they are highly depend­ Another positive development is country. Government has initiated ent on government programmes. a collaborative effort between the a number of programmes aimed to Obtaining the right permission and Department of Water Affairs (DWA), support IPPS. licensing agreements is a long and National Treasury, Eskom and the intricate process, often involving NWRI under coordination with the Regulatory the Departments of Public Enter­ DoE. It entails the implementation environment prise, Energy, Water Affairs, Eskom of a pilot project for small hydro­ and the National Energy Regula­ power generation at the Vaal Dam ollowing Cabinet’s approval of tor of South Africa (NERSA) and as well as the compilation of a list Fthe White Paper on Renewable more. Furthermore, IPPs are largely of 20 other possible sites earmarked Energy, the Department of Energy dependent on Eskom, which controls for feasibility studies for small-scale (DoE) proceeded with the develop­ who can access the grid. Anton- hydropower plants. These sites are ment of its renewable energy strat­ Louis Olivier, NuPlanet MD agrees located within government infra­ People started to egy. The implementation plan of the that rules and regulations that IPPs structure, but IPPs could be allowed switch from hydro- to various technologies was identified have to adhere to are big factors. access for hydropower development coal-based electricity He adds that start-up funds are also should the process be completed after the establishment in a macroeconomic study under­ of Eskom. Today, taken in 2003. This study highlighted often substantial, and there is thus successfully. remnants of the Graaff the technologies to be implemented huge risk involved. Henriëtte Anderson, DWA Chief Electric Lighting Works first, based on the level of commer­ Nevertheless, he is positive that Director of Engineering Services, says are reminders of South cialisation of the technology and the country’s Integrated Resource that an initial screening process has Africa’s history with Plan for 2010 to 2030 could be a commenced and will be completed in small hydro power natural resource availability. Mini- plants. hydroelectric schemes were included massive injection for the renewable the near future. During the process, a sector. The plan envisages renewa­ hydropower engineer investigates all bles contributing 42%, or 17 800 the sites for possible fatal flaws that MW of the country’s new generation IPPs may encounter should the sites capacity by 2030. The DoE also allo­ be developed. These could include cated capacity across various renew­ issues such as sustainability, afford­ able technologies, with 1 850 MW ability and technical, operational and set aside for onshore wind, 200 MW financial risks. It is foreseen that the for concentrating solar thermal, initiative will help create an enabling 1 450 MW for solar photovoltaic environment for IPPs to gener­ solutions, 12,5 MW for both biomass ate hydropower after a competitive and biogas, 25 MW for landfill gas tendering process has been followed. capacity, 75 MW for small hydro, and Anderson adds that it seems “very a further 100 MW for other small- likely” that they will proceed with scale IPP projects of less than 5 MW. some of the sites. The way forward Speaking on small hydro specifically, after the screening of these sites has Olivier says that the generation of been concluded will be determined by

Bruce Sutherland, City of Cape Town City of Cape Sutherland, Bruce 75 MW would create hundreds of job the National Treasury. 

20 The Water Wheel November/December 2011 Breaking news

World agri award – SA does it again

outh Africa has confirmed its and different irrigation methods. amount of water for a specific com­ Below: Newly-elected status as a world leader in the In addition, the effect of soil water mand area. The department has also Chair of the African Working Group, Dr drive towards irrigation water management options, such as deficit endorsed SAPWAT3 as a tool to Andrew Sanewe, new useS efficiency following another irrigation, can be evaluated. issue water use licenses for irrigation ICID Vice President Dr international award. Irrigation strategies can be varied purposes. Gerhard Backeberg This is after the International to demonstrate the effect of different Apart from the WatSave award, and Chair of the South Committee on Irrigation and Drain­ strategies on irrigation requirement. the South African delegation walked African National Committee on Irrigation age (ICID) awarded the country its This allows the user to devise irriga­ away with several additional acco­ and Drainage (SANCID), fourth WatSave Award in the last five tion strategies aimed at maximis­ lades from the ICID congress. Felix Reinders, at the years during the 21st International ing rainfall use efficiency and thus WRC Director: Water Utilisation in ICID Congress in Iran. Congress on Irrigation and Drain­ reducing irrigation water require­ Agriculture Dr Gerhard Backe­berg age held in Iran earlier this year. The ment. In addition, salinity stress was appointed Vice President while Bottom: : SANCID Chair, Felix Reinders, receiving accolade in the ‘Innovative Manage­ and water stress situations can be WRC Research Manager in the same the WatSave Award ment’ category was awarded to the imitated. All irrigation requirement department, Dr Andrew Sanewe, was from ICID President, Prof SAPWAT3 irrigation planning and estimates can be stored and revisited appointed chair of the African Work­ Chandra Madramootoo, management tool project manag­ to determine what effect changes in ing Group. In addition, South Africa on behalf of SAPWAT ers Pieter van Heerden and Charles irrigation water management, irriga­ won the award for ‘Best National project leaders Pieter van Heerden and Crosby. tion system and changes in planting Committee’ for a third year in a row. Charles Crosby. The original SAPWAT program dates could possibly have. This is a considerable achievement was released in 1999. Since then the Since its introduction, SAPWAT considering that ICID is represented irrigation requirement and scheduling has been applied by more than 300 by 110 member countries.  tool has gained general acceptance in users in 13 countries, including South Africa. SAPWAT is not a crop Angola, Mali, Mozambique, Swazi­ growth model, but rather a planning land, Niger, Namibia and Uzbeki­ and management tool relying heavily stan. Through the years the program on an extensive South African climate has been continuously upgraded and and crop database. It is general in improved, mainly with funding from applicability in that the same proce­ the Water Research Commission. dure is used for vegetables and field The latest version, SAPWAT3, was crops, annual and perennial crops, as released in 2008. Today, SAPWAT3 well as pasture and tree crops. With is used by all irrigation designers in this program it is possible to simulate South Africa to optimise water use wide-bed planting, inter-cropping to its fullest extent. The latest version is designed for maximum user interaction, an approach which contributes to the user’s understanding of issues affecting good irrigation plan­ ning and management. This approach has the added benefit that SAPWAT3 serves as a good training and demon­stration aid. Water savings have been achieved in a number of water man­ agement areas and, as a result, officials of the Department of Water Affairs are using the tool to quantify the optimum

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