As engineering solutions provider Zest WEG’s holding company, Brazil-based WEG, is already well-established in the wind energy sector in South America, Zest WEG is developing its own momentum in this segment locally.
According to Zest WEG integrated solutions executive Alastair Gerrard, the role of WEG in wind energy has grown well beyond supplying generators to other original-equipment manufacturers (OEMs). Having developed its own direct drive, gearless wind turbine with a technology partner, and then acquiring that business in 2016, WEG is now a “turbine OEM with ambition”.
“Having its own turbine technology allowed WEG to enter the market with a 2.1 MW wind turbine solution with no gearbox, bringing various benefits that are in line with market expectations. In recent years, WEG has also developed a 4.2 MW turbine, as the sector has sought larger capacity solutions,” Gerrard notes.
This has placed the company in a good position to serve a market that is looking for increased energy output and relatively lower balance-of-plant costs. The higher hub heights of these larger units also mean better energy capture and energy yield, making them more popular among wind farm developers.
“Among the advantages of having no gearbox in the wind turbine is increased efficiency, less noise, less weight and more reliability,” he says.
“Successful wind energy projects are all about their turbines’ energy yield, reliability of supply and minimum downtime for maintenance over their lifespans. “Wind farms are designed to maximise the availability of energy in the most efficient way.”
Another of WEG’s wind turbine features is to install the turbine’s transformer in the nacelle, rather than at the foot of the turbine. With the alternator generating electricity at a low voltage of 925 V, the transformer can then step this up to 33 kV before it is transmitted the 120 m to 125 m distance down the tower. This medium voltage transmission leads to lower losses in energy.
It also means considerable savings in balance-of-plant infrastructure, as no transformer is required at the tower base, or additional civils work on which to position this item.
“This transformer has also proved its reliability in the field, and makes a valuable contribution to the overall efficiency focus in the turbine’s design,” he says.
WEG’s track record as an OEM in wind energy is well demonstrated by the 647 MW of wind turbine capacity already installed in the market – mainly in South America. The success of its turbine offering extends into the future, with over 180 MW currently in the project pipeline. Unsurprisingly, it was not long before Zest WEG started looking at local opportunities.
“With the growth of wind farms in South Africa, Zest WEG took a strategic decision a couple of years ago to bring WEG’s technology into the country,” Gerrard says. “Our extensive local footprint and market knowledge means that we are well placed to do this, and to expand into Africa.”
He highlights the importance of wind turbine OEMs being involved in wind farm projects from an early stage, as the wind turbine itself is ultimately what determines the architecture of the plant.
“Everything from micrositing to electrical and civil balance-of-plant requirements hinges on the selection of the wind turbine technology,” he says. “The fifth round of government’s Renewable Energy Independent Power Producer Procurement Programme will hold potential for us.”
He notes that Zest WEG, through the preparation of micrositing studies using the WEG wind turbine technology, is advanced in working with wind farm developers to optimise their projects for higher energy yields, and “the feedback is positive”.
Underpinning Zest WEG’s offering is the grid code compliance of its wide range of products and solutions. As an established supplier to the national utility, the product range meets all the necessary regulations and standards. Zest WEG is also well versed in local content requirements.
“We are fully on board with skills development and skills transfer as part of our empowerment mandate in the wind energy space,” Gerrard says. “At the same time, we’ve prepared the ground for our supply chain development to ensure local participation in aspects like tower manufacturing and construction, and the installation of the turbines.”
Operations and maintenance are typically conducted on a long-term contract basis, which will also provide opportunities to involve South African companies as part of the local content equation. With Zest WEG’s 40 years as a local supplier and manufacturer, with all the required skills and official qualification criteria, it can also provide much of the electrical balance of plant. These aspects would range from electrical construction services to Zest WEG’s locally built power transformers.
“While we can leverage off the tried- and-tested turbine technology from Brazil, we have the experience and capacity to adapt this to a local model, suitable to the market here and local content requirements,” he says. “Vital to our contribution is our well-established manufacturing base, our services network and market understanding.”
Within South Africa, Zest WEG’s branch network puts skills and resources close to wind farms for prompt support. There is also specialised expertise available from the main technical team based in Johannesburg, and a high-level engineering team in Brazil.
The company also has other African opportunities in its sights, and the future will see more attention on wind energy prospects throughout sub-Saharan Africa. Its extensive population of products in the field around the continent is supported by a large network of value-added resellers in various African countries.