- Category: Water Management Features
- Published on 19 January 2017
- Hits: 82
By Martin Czernowalow
As few suitable sites remain for the construction of new hydropower plants, government is thinking about retrofitting existing water infrastructure.
South Africa’s government is mulling over the generation of hydropower by retrofitting existing infrastructure — including big dams, water schemes and canals — as it seeks to bolster the renewable energy portion of the country’s energy mix.
This is according to a Department of Water and Sanitation draft sustainable hydropower generation policy, which was gazetted last year and forms part of the country’s efforts to cut its reliance on fossil fuels for electricity generation.
In the draft policy, the Department of Water and Sanitation maintains that the country has the potential to develop hydropower at existing water infrastructure. “Instead of dams being constructed … existing reservoirs that are used for other purposes can be fitted with hydropower plants in order to augment electricity supply towards meeting peak electricity demands,” it states.
Due to the shift towards renewable energy, hydropower projects — such as those that would see technology retrofitted to existing dams — are environmentally and financially attractive as a result of pre-existing suitable water infrastructure.
According to the ministry, it would collaborate with the Department of Energy, which is running the Independent Power Producer (IPP) Procurement Programme, through which government procures electricity generated from solar, wind, biomass, small hydro and landfill gas power plants. Private sector investment in the IPP Procurement Programme, which was launched in 2011, currently exceeds R194-billion.
The Department of Water and Sanitation owns 316 large dams, which are located across South Africa. To date, 30 dams have been rehabilitated and a further six are currently undergoing rehabilitation, with another 32 projects at various stages of design and tendering.
South Africa’s National Development Plan sets a target of 20 000MW of renewable energy capacity, while the updated Integrated Resource Plan for electricity (released for public comment in November) calls for 55GW of renewable energy capacity to be installed between 2020 and 2050.
However, market commentators believe that despite investor appetite for projects in the water sector, the number of solar and wind projects in South Africa outstrips water projects. And while hydropower in South Africa has not been exploited to its full potential, it is expected that the majority of hydropower projects in South Africa will be carried out on a smaller scale due to the country’s available water resources.
Few sites remain
This largely concurs with a report in the Hydropower & Dams World Atlas 2016, which notes that, in recent years, dam construction has slowed down in South Africa, with emphasis changing to optimising the use of existing resources.
“Few suitable sites remain. However, several water resources development projects could still proceed, including the Mzimvubu Water Project in the Eastern Cape, which would involve the construction of the Ntabelanga Dam, on the Itsitsa River,” says report.
“Another scheme in the planning phase is Mkomazi, in KwaZulu-Natal, which includes the construction of the Smithfield Dam. Other possible schemes would be the Vioolsdrift Dam (within Namibia), on the Lower Orange River, in the Northern Cape, and the Nwamitwa Dam, on the Groot Letaba River, in the north of the country, both for water supply.”
According to the latest figures quoted by the Hydropower & Dams World Atlas 2016, the gross theoretical hydro capacity of South Africa is 73 000GWh per year, while the technically feasible capacity is 14 000GWh per year. The country’s economically feasible hydro capacity is 47 000GWh per year.
“Of the technically feasible potential, about 90% has been developed so far (including pumped storage). There is an installed pure hydro capacity of 660MW. Eskom owns four large hydro plants, the two most significant being Gariep (360MW) and Vanderkloof (240MW). Hydro produces, on average, 3 000GWh per year,” says the report.
Two other large hydro schemes are also currently in the pipeline, with the first being Eskom’s Ingula Pumped Storage Scheme, which is expected to be commercially operational in mid-2017. This scheme is expected to add 1 332MW to the national power grid, but is about four years overdue and about R27-billion over budget, said to cost a total of R35-billion.
“Instead of dams being constructed … existing reservoirs that are used for other purposes can be fitted with hydropower plants in order to augment electricity supply towards meeting peak electricity demands.”
The second is the R25-billion binational Lesotho Highlands Water Project, which is currently in its second phase of development. However, completion has been delayed by about a year, as the project became mired down in allegations of corruption and impropriety that reach all the way up to South Africa’s Department of Water and Sanitation. Upon completion, the Lesotho Highlands Water Project is expected to provide about 1 000MW of power to Lesotho, and water to South Africa’s Gauteng province.
Smaller hydropower projects currently being developed include the 3MW Sol Plaatje scheme, the 4MW Merino project and the 400MW Palmiet project.
Nonetheless, research shows that all feasible large-scale hydro potential has now been tapped, and that pure hydro contributes about 1.5% of national electricity supply in an average year in South Africa.
“There is also 1 400MW of pumped storage capacity in operation, with 1 332MW under construction (Ingula). Earlier this year (2016), the first two units at Ingula were synchronised to the grid. All four units should be in operation by next year (2017),” says the Hydropower & Dams World Atlas 2016.
“Meanwhile, feasibility studies have been undertaken for two more pumped storage schemes in either the Western or Eastern Cape (1 000MW), and another 120MW of pure hydro is being studied on the Orange River, just below the Vanderkloof Dam.”
In terms of smaller hydropower projects, studies carried out in 2010 indicate that up to 47MW could be developed at small schemes in the future. Currently, 61MW of small hydro capacity is in operation at four plants, producing 350GWh per year.
“The 10MW Neusberg plant, on the Orange River, went ahead in March last year (2015); it is the first run-of-river hydro scheme to be developed under South Africa’s Renewable Energy Power Producers’ Programme. Output will be sold to Eskom under a 20-year PPA [power purchase agreement]. The plant is owned by Kakamas Hydro Electric Power,” the Hydropower & Dams World Atlas 2016 states.
“Meanwhile, NuPlanet, another private small hydro developer, has the 4.5MW Stortemelk plant under construction on the Ash River, in the Free State province. The plant is expected to begin operation later this year (2016).”
The report also notes that marine energy has been studied and that there is potential for wave power on the south and south-western coastlines, and for ocean current instream devices along the eastern coast.