By: Lesego Malete
With that in mind, there have to be alternatives. While some may say it is too late to be thinking about alternatives, this is something we should have thought about years back. The saying goes: “It’s better late than never”.
One of these alternatives is wind energy but the question we’re asking is: “Is South Africa utilising this option and what do we know about wind energy?”
We sit down with a knowledgeable man on this topic, Andre Otto, a consultant and former employee at the Department of Energy (DoE) who has been part of the extensive research on wind energy. But that’s not all. We also speak to wind turbine manufacturers about their products and their views about this interesting topic.
Let’s take a step back
The question on everyone’s mind right now should be how this technology works and how its going to affect me in future. “Wind energy is one of the oldest applications of the environment; if one looks back, it was and is still being used for sailing boats and ships. In South Africa we tend to forget that there are thousands of windmills out there pumping water for many years now. It is only now with our capacity, water constraints and climate change concerns that wind energy technology is increasingly being used for electricity generation in South Africa,” says Otto.
According to historians the first electricity wind turbine was installed by a Scottish man, James Blyth in 1887 for his home. Thereafter, American inventor Charles F. Brush built the first automatically operated wind turbine for electricity production in Cleveland, Ohio. However, it was in the 1890s, that Poul la Cour, a Danish scientist and inventor, built wind turbines to generate electricity, which was then used to produce hydrogen. The Smith-Putnam wind turbine was the first megawatt-class wind turbine which was synchronized to a utility grid in Vermont in 1941.
How does it work?
Wind turbines convert wind energy into electrical energy using wind flowing over turbine blades to turn an electricity generator.
What we currently know about wind technology
According to one of South Africa’s big wind turbine manufacturers, Kestrel, an important factor to know about this technology is that it has improved exponentially in the last decade. “The fact that the product is incentivised internationally is not well known in South Africa and a push from this side could increase its use and advantages in South Africa,” says the company.
Otto says, in order for South Africa to start using wind energy technology on a higher scale, the country needs to do thorough research on what works and what doesn’t. He lets us know that extensive research is being carried out in collaboration with government, power utility Eskom and investors.
South Africa started to seriously look into wind technology and connecting to the grid in 2000 after liaising with Global Environment Facility (GEF) and the Danish government on the ‘Darling Wind Farm project’. Eskom has a test site with three vertical axis units supplied by different manufacturers in the Cape. This is a test site for the power utility to assess the technology and when the time comes, how they will connect it to the grid. At the same time, government also started working on a ‘demonstration programme’, which is a fully independent commercial project that’s been running since 2008 in the west coast, Saldanha Bay. The total power output is 5.2 megawatts (MW). “South Africa has not yet used independent power producers to any extent. The whole idea with the project is to learn by doing, showing that it is possible for the private sector to generate and sell bulk renewable energy, development of generic Power Wheeling and Power Purchase Agreements, bankable financial models, grid connection and more.
There are three grid-connected installations at present namely:
||Size (MW installed)||Comment|
||Eskom research station|
|Darling Wind farm||5.2||IPP built with assistance of Danish grant funding|
||1.8||IPP - part of larger initiative that has not made progress as yet|
Research from this project has proved that there is potential in terms of the wind resource and scaling up wind development in South Africa. Now the real question is how will it be set up in this country? “With all renewable alternatives, the cost is expensive relative to subsidised fossil fuels prices,” says Otto. However, he believes that although setting up will be expensive, its return costs will be beneficial in future.
“With assistance from GEF and the Danish government, who have extensive knowledge on this subject, the South African Wind Energy Programme (SAWEP) has been developed” Otto says, “The whole idea was to figure out what the general issues are for commercialisation of wind energy that we need to look into such as government policies, legal and regulatory frameworks and how do you fund these things?
The idea behind SAWEP is to research and conduct fact finding on important issues i.e. how much wind is there? This is important because everyone has their own opinion and views about how much wind there is. Therefore, it was important to develop the programme to come up with an objective and transparent assessment of a practical potential in South Africa about wind technology. Only then can all stakeholders engage in a conversation of what works and what doesn’t. “Capacity building is also important in terms of getting stakeholders involved in wind energy development and we need to know how to get capacity developed especially for operation and maintenance,” says Otto.
Working with what we have
Government’s wind Atlas project plays a major role in determining the way forward for wind energy. “Making use of state of the art wind resource assessment methods, national, regional and local wind resource planning can be done and viable wind ‘hot spots’ can be identified and developed. Application of the numerical wind atlas saves time and money in calculating local wind climates that can be used to predict, without physical wind measurements, key parameters such as wind speed, frequency, direction, estimated power output and wind farm layout at any site covered by the numerical wind atlas. Integrating (GIS) the numerical wind atlas and data from electricity networks, roads, towns, and environmentally sensitive areas, for example, enables decision-makers, developers and financiers to identify upfront potential viable wind ‘hot spots’ in reasonable time and before lengthy and costly wind measurements need to be done,” states DoE.
Another of the outcomes expected from SAWEP’s implementation is the wind resource assessment, for government to assist interested public and private sector entities with the generation of reliable wind energy data and other necessary information for wind energy development;
Wind Energy Capacity Credit
The techniques which have been applied to measure wind in the past have produced inconsistent results. According to Otto, the methodology that was used was not incorrect; however the source of wind data is suspect. He gives us an example: “weather measurement stations are 5,10 to 15 metres (m) high, today wind turbines are 60 up to 90 m and higher. ” The wind needs to be measured at the height of the wind blades. The reason for this is wind turbine power output for this is proportional to the cubed of the wind speed. This means a small variation in the wind speed has a large effect on power generated. This impacts a lot on energy security and on finances as well. It’s important to measure or predict the wind speed as accurately as possible because of the cubed variation. For example if we’re now using data from a 10 m high wind turbine to try and extract what it is going to be at 90 m it creates huge errors.” So from this, a decision was made to make use of state of the art modelling combined with a proper wind measurement programme to validate the models.
While speaking to Otto about this topic, he said they were going to launch the first verified Numerical Wind Atlas models in March (Deputy Minister launched it in March 2012). With these results, verified with proper wind measurements, they can verify how the system works and show government, Eskom and other stakeholders the wind maps for certain areas and predict the wind resource from the data produced. The information is available to public to prove its credibility and ensure accuracy levels.
Wind: on and off
One of the big concerns on wind energy for government and Eskom is the issue of intermittence – meaning it goes on and off. However, Otto says this is an incorrect term for wind energy. DoE agrees and states: Even in extreme conditions, such as storms, it takes several hours for wind turbines in a system area to shut down. Moreover, periods with zero wind power production can be predicted and the transition to zero power is gradual. The term intermittent’ is therefore inappropriate for system-wide wind power and the term ‘variable- output’ should be used instead. Because the wind resource is variable, this is sometimes used to argue that wind energy is not reliable per se. No power station or supply type is completely reliable; all system assets fail at some point. In fact, large power stations that go offline do so instantaneously, whether by accident, by nature or by planned shutdowns, causing loss of power and an immediate requirement to restore power. When a fossil or nuclear power plant trips off the system unexpectedly, it happens instantly. That is true intermittency. Power systems have always had to deal with these sudden output variations of large power plants as well as the variable demand. By contrast, wind energy does not suddenly trip off the system. Variations in wind energy are smoother when there are hundreds or thousands of units rather than a few large power stations, making it easier for the system operator to predict and manage changes in supply as they appear within the overall system. The system will not notice the shut-down of a 2 MW wind turbine. It will have to respond to the shut-down of a 500 MW coal fired plant or a 1,000 MW nuclear plant instantly.”
Now that South Africa has the data available, it can be put to good use and applied to models for realistic predictions for variations on the grid. “Previously this could not be done because of discrepancies but now we have the data that can verify it.
There are three key issues that needed to be addressed to get the ball rolling:
How much wind is there (using a traceable verified wind atlas)
Is there availability (if there’s no wind, what do we do?)
The difference between vertical and horizontal
There are primarily three types of wind turbines, the Horizontal Axis Wind Turbine (HAWT), the Vertical Axis Wind Turbine (VAWT), and other variations.
Benefits of wind energy
At the top of the list of the advantages of the technology is that wind energy does not require water to work. Moreover, Kestrel says, “Wind energy is non-polluting, and reduces the demand for higher-impact electricity from thermal stations (e.g. oil, natural gas, coal ), hydroelectric dams and nuclear generators.”
The company also names the following as important:
Energy Independence - Wind turbine systems can assist you in gaining more independence from your local utility. They can also make you less susceptible to power interruptions from the grid.
Cost - Wind energy systems are one of the most cost-effective home-based renewable energy systems. Depending on your wind resource, a small wind energy system can lower your electricity bill by up to 100 percent. They can also help you avoid rising and volatile electricity prices.
Remote Electricity Generation - If you are at a distance from existing grid lines, generating your own electricity helps you avoid the high costs of having utility power line extensions.
“Renewables work when you integrate them together. The mix makes it much more viable, giving a much more predictable resource at a much higher value. The big opportunity would be to start integrating all these different things and fossil fuels. Wind energy is a key partner in the renewable mix, at the moment, if I look at SA regarding renewables, I would say our best resources are wind and solar. Yes, we have biomass and hydro, but biomass is dependent on sugarcane and sugarcane is dependent on sugar price which in turn is dependent on farming. Wind and solar are independent and we have plenty of it, that’s where the integration can begin” explains Otto.
South Africa has good coastal wind resources. However the Wind Atlas research shows that the inland areas also have good wind resources that could even be better than the coastal area which is something experts were not aware of in the past. “On the lower ground, the friction with the ground takes out energy from the wind. That’s why wind turbines need to go higher,” says Otto.
It will not work if…
The technology does not work everywhere therefore feasibility studies are imperative to find out where it will work and where it will not work. Otto adds to that, “The problem sometimes is people put in a wind turbine and do not have the right measurements. When it doesn’t work, they say wind energy does not work. Kestrel says another disadvantage with this is, “In current grid connected areas, unsubsidised wind turbine systems can be costly.”
The South African Wind Energy Association (SAWEA) says the usual objections is that it is not dependable. However dispersion of wind farms over the country ensures that a minimum dependable generation from wind is possible, particulary given South Africa’s vast landmass.
Countries such as China have surpassed us by far; Otto believes we’re catching up by doing this systematically and learning at the same time. “We have an opportunity to integrate all these technologies (solar, heat pumps, biomass, wind…) in packages that nobody else is doing that are economical viable and producing reliable power. In the developed world, they do not have the logistic problems that we have. In Africa, in some places large wind turbines will not be suitable but if a smaller turbine can be combined with another technology, this could work. Moreover, Kestrel says we are missing out on opportunities because we currently do not have a rebate in place, this means people are investing less in wind turbines and putting more pressure on the national grid
Standards do apply
“Cheap and uncertified wind turbines have given wind technology a bad name and consumers should be very cautious when investing in wind technology not to fall into this trap,” says the wind turbine manufacturer. The turbines need to be approved by the South African Bureau of Standards (SABS). The country adopted the international standard for turbines from the International Electrotechnical Commission (IEC). The SABS test verifies these standards according to the South Africa National Standards (SANS) 61400. In regards to installations, they need to have certification, Otto says the country needs to regulate this, “We need to look into operator training, like the national qualification framework and the SETAs, the qualification must be standardised.”
The SABS is a permanent member of the IEC Technical Committee 88, which is responsible for standards relating to wind turbines.
Work is being done
It is obvious from what’s been said, work is being done to implement wind energy as an alternative for electrical energy production. Extensive research by various stakeholders is on-going to ensure we get the numbers and facts right before getting the full go-ahead.
In December last year, government together with Denmark announced the launch of the’ South African Wind Energy Awareness Campaign: Powered by Wind. This is the country’s first campaign focused on creating all-important awareness around wind energy and its benefits on a local environmental and economic level.
The campaign will be rolled out in phases and focus on targeted groups - civil servants; Business; local communities in Western, Northern and Eastern Cape; and primary school children from grades four to six in the three provinces and Non Government Organisations. “The objective of the campaign is to create awareness around wind as a resource of renewable energy within the country; it has positive economic and job creation implications as well as dispelling myths and common misperceptions.
At the helm of the campaign will be two uniquely created characters: Mr Windy and Mrs Coal who will demonstrate to South Africans how wind and coal can work together to create energy for current and future generations.
In order to maximise awareness in each group, specific materials and elements have been developed. For example, for primary school children, comprehensive workbooks have been created by a team of experts. It will also be available in electronic format and will coincide with children-friendly cartoons,” states the Minister of Energy, Dipuo Peters.
Business will receive fact folders which will contain short, concise facts on how wind energy will benefit business and the South African economy. An animation, adult-focused clip - starring Mr Windy and Mrs Coal - has also been developed and is available for viewing on a dedicated Youtube channel. All the target group campaigns will be supported by public relations and marketing efforts and will, through electronic, print, and social media communicate the message of the SA Wind Awareness Campaign: Powered by Wind.
Andre Otto – consultant
Kestrel Wind Turbines
The South African Wind Energy Association