Netherlands-based renewable-energy company Aeolus Associated plans to have the first phase of its R15,5-billion electricity generation project at the proposed Saldanha industrial development zone (IDZ), in the Western Cape, up and running by 2013.
The overall project will entail the generation of up to 1 060 MW of electricity for the IDZ through combined-cycle gas turbine (CCGT) power plants and renewable-energy sources, by 2019.
Of the 1 060 MW, 340 MW of electricity will be generated from renewable-energy sources, such as solar, wind and biomass, says Aeolus Associated CEO Dr Leo Van Gastel.
These alternative power sources will predominantly comprise solar power, with 200 MW being generated from photo- voltaic (PV) panels. Wind energy is expected to produce about 100 MW of electricity and wind turbines will be erected in between rows of PV panels.
The power will be generated through an independent grid and at lower tariffs than State-owned power utility Eskom’s grid, says Van Gastel.
Cape Chamber of Commerce West Coast chapter chairperson Luna Vermeulen explains: “Eskom tariffs average 43c/kWh. However, further electricity price increases have been approved by the National Energy Regulator of South Africa, which will see Eskom’s tariffs increase to 67c/kWh by 2013.”
The first of the two 360 MW CCGT power plants is expected to start producing elec- tricity by 2013. The developer estimates that the baseload power from this unit will be sold to offtakers at about 60c/kWh.
Initially, Aeolus Associated will use compressed coal gas to be delivered to Saldanha by rail to power the CCGT plants. The company will later switch to imported liquid natural gas once it becomes available.
Several sources of gas are being considered. These include imported natural gas, gas from South Africa’s offshore fields, coal-bed methane and, in future, shale gas. At present, however, the old fashioned ‘town gas’ made from coal is preferred.
Meanwhile, Vermeulen says that a number of investors are poised to invest billions of rands in developing green projects and other industries at the IDZ.
Titanium and Zirconium Refinery
The largest project proposed to be implemented at the IDZ is the construction of a titanium and zirconium refinery by investor consortium Rare Metal Industries (RMI), at a cost of between $1,2-billion and $1,5- billion.
Mining Weekly reported last year that the proposed plant would be the world’s first integrated metals plant producing titanium, zirconium, magnesium and silicon.
It is envisaged that, at full operational capacity, the plant would produce 50 000 t/y of magnesium, 15 000 t/y of titanium, 8 000 t/y of silicon and 2 000 t/y of zirconium, coupled with some derivative products.
The titanium and zirconium will come from diversified mining group Exxaro’s Namakwa Sands heavy minerals mining and beneficiation plant, north of Saldanha.
South Africa has the world’s second-largest reserves of zirconium and titanium. However, these metals are currently being exported in raw form, beneficiated and imported back into South Africa. Beneficiating 3% of the country’s titanium would create a multi- billion-dollar-a-year industry, says RMI.
Quality alloys, produced by RMI, are in great demand within high-technology industries, such as the manufacturing of turbines for jet engines.
To process ore, temperatures of about 600 ˚C must be maintained. To do this, a jacket of molten salt is used to insulate parts of the machinery and RMI will, therefore, become a customer for a proposed desali- nation plant and the large quantities of brine produced.
Multidisciplinary Dutch firm Norit business development assistant Alexander Horvathreports that the company is investigat- ing the desalination of seawater at the proposed Saldanha IDZ through an osmosis plant.
He believes that water can be produced at lower tariffs than the current water supply tariffs. The retail price of water in Cape Town ranges from R4,55/kℓ to R23,42/kℓ, which government is going to increase in a ‘stepped tariff’ scale. The desalination plant will produce desalinated water at a cost of R4/kℓ. This could be further reduced to R1,90/kℓ if a more complex plant, which recycles used water, is built.
Horvath says that, currently, 9% of the water consumed in the world is desalinated. There are added benefits to building a desali- nation plant as the waste brine would be processed to extract rare minerals, such as lithium and magnesium, before the remainder is discharged into the open ocean.
Water will be returned to the sea, which would be cleaner than the water taken from the ocean as the water would be stripped of heavy metals. Although there would be a concentration of salt at the discharge points, this would rapidly dissipate in the open sea.
Norit plans to dilute the seawater with treated recycled water, which will reduce the cost of the desalination process. The desalination plant is also more efficient when salt concentrations are lower. This results in fresh water from the reverse- osmosis plant being superior to present municipal water.
The company is considering the possi- bility of using only wind or solar power to run the plant. This is possible as water can be desalinated when wind or solar power is available and the water can be stored in reservoirs for use as required.
One of the challenges in using wind turbines for other applicationss is that power is generated at night, when the demand for electricity is low; however, this ‘night power’ would be suitable for desalination.
Vermeulen notes that these projects will create many jobs in the construction phase and more jobs when the industries are operational.
- IDZ in South African renewable-energy push (saaea.blogspot.com)