Wind turbines are growing in popularity in South Africa
A wind turbine works by harnessing the power of the wind to create wind energy. The wind turns large blades around a rotor. This, in turn, powers a generator, which creates electricity.
A wind turbine can be on land or offshore. Land-based turbines can create between 100 kilowatts (KW) to many megawatts (MW). They are typically placed together to form wind plants.
Wind turbine capacity
Generally speaking, a wind turbine’s capacity depends on a number of factors, for example, its size, the wind’s speed and where the turbine is placed. Typically, offshore wind turbines produce more electricity than onshore ones due to higher wind speeds at sea.
Wind turbines can be up to 200 metres tall with rotor blades up to 60 metres long. A single turbine has a capacity of 2.5 MW to 3 MW and can produce over six million kilowatt hours (kWh) per year. On average, a wind turbine lasts between 20 and 25 years.
South Africa’s wind turbine energy generation
As of October 2019, almost 3.35 gigawatts (GW) of wind energy was connected to the South African grid. By 2030, the government plans to bring an additional 14.4 GW onto the grid, increasing the total amount of installed wind capacity to over 17.7 GW. This will be equal to 17.8 per cent of the total grid. Approximately R209.7 billion worth of wind projects are currently under construction.
Why wind energy is so popular in South Africa
Reaching net zero
Wind energy has enormous potential to transition South Africa’s energy sector away from being heavily reliant on fossil fuels and towards renewables. President Cyril Ramaphosa, the leadership of state-owned energy company Eskom and other political leaders all support renewable energy.
South Africa needs to transition away from fossil fuels to meet its goal of being net zero by 2050. Its economy is heavily reliant on coal, with nearly 80 per cent of the country’s electricity generated from this fossil fuel. South Africa plans to decommission about 10.5 GW of coal power by 2030 and 35 GW by 2050. Nearly 30 per cent of new renewable energy that will replace this coal energy will come from onshore wind, solar and other technologies.
This combination of factors, the need to ween the country off coal and the ever-declining cost of wind energy are driving the popularity of wind. As of late 2021, there were 12 onshore wind farm projects under construction in South Africa, in addition to the 27 wind farms already operating.
South Africa also has significant offshore wind resources off its coast. Used to its full potential, South Africa’s offshore wind energy resources could power anything between 15 to 800 per cent of South Africa’s electricity demand. This is according to new research from the University of Stellenbosch.
New wind farms being built in South Africa
As of early 2021, there were 27 wind farms operational in the country. These farms power about four million households, according to the South African Wind Energy Association.
The largest renewable projects in South Africa are all wind farms. In January 2020, wind contributed 52 per cent of all renewable energy to the South African grid. Among the biggest wind farms is the Longyuan Mulilo’s Number 2 North Wind Farm in De Aar, in the Northern Cape province. This wind farm is 139 MW. There is also the Loeriesfontein Wind Farm with a generation capacity of 140 MW and the Khobab Wind Farm next door with a capacity of 140 MW.
Cost of wind energy
Wind energy is much cheaper than energy generated by burning coal. The price of new wind energy has dropped by nearly 80 per cent since 2011. The tariff in October 2021 was about R0.50 per kWh. Meanwhile, the cost of electricity from new coal is R1 per kWh.
Wind energy can also deliver more return on investment than new coal, according to expert analysis. For example, Eskom’s two new coal power plants – Medupi and Kusile – are years behind schedule and billions over budget. At a cost of over R450 billion, each station is supposed to deliver 4,800 MW of electricity.
But, for the same price, South Africa could build over 17,000 MWs of wind energy capacity. However, experts caution that wind energy plants do not always deliver all their energy capacity. Therefore, while these hypothetical wind farms are unlikely to produce the full 17,000 MW of energy, Medupi and Kusile are unlikely to produce their full capacity either. Bungled contracts, corruption and design defects mean that both stations will produce little more than building wind farms would. Although, it is not uncommon for mega construction projects, like new coal plants, to be prone to corruption and cost-overruns.
This cost analysis favours wind energy before even taking into account the costs of Medupi and Kusile’s pollution and greenhouse gas emissions. More broadly, renewable energy, like wind and solar, is cheaper than coal. The cost of any renewable energy plant is at least 30 per cent cheaper than building the cheapest new coal plant. This is according to the cost per unit of electricity produced by either technology. By 2030, it will be cheaper to run renewable plants than existing coal stations.
Wind turbines provide clean household energy
According to Eskom, an average South African household uses 30 kWh hours per day or 10,950 kWh per year. Taking into account variables like location and wind speed, a 15 KW turbine would be enough to provide electricity to a household.
Like all forms of energy, there are some downsides to wind energy. But, compared to the enormous environmental and human cost of fossil fuels, these are minuscule.
For example, wind sites on land are often remote. This means transmission lines must be erected to make sure electricity reaches cities where it is needed. There have also been concerns about small numbers of bat and bird deaths, but research is ongoing to minimise this risk to wildlife.
So, while fossil fuel sources of energy cause global warming and pollute the air, for example through carbon dioxide and sulphur emissions, renewables like wind are clean, sustainable and cost-effective.