Metrowind Van Staden's first turbine come's online
01 Feb 2016 | Admin Author
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The first of nine wind turbines that will make up Metrowind Van Stadens wind farm, near Port Elizabeth, went online on Friday.
And according to the company, the remaining eight will be assembled over the next two months.
The Metrowind Van Stadens wind farm also boasts some firsts for both South Africa and the engineering and construction firms associated with the project.
Evan Jones, engineering manager for energy at lead contractor, Basil Read Matomo, says they're making use of the largest crane to ever used in South Africa to assemble the wind turbines.
"For us the use of the largest crane ever used in South Africa has simply been incredible; we have never before seen a crane of this capacity," said Jones.
"The Terex TC 2800 has a lifting capacity of 800 tons, and is the only crane able to simultaneously reach the height of the wind towers and carry the weight of the nacelles, hubs and blades," he added.
He says the crane was imported from Poland has a lifting capacity of 800 tons.
The crane was imported from Poland earlier this year to facilitate the lifting of the 120 ton nacelle. It took 56 trucks to transport the crane to site, where a normal 650 ton crane requires only 20 trucks. Moving it from one turbine site to another also takes days, said Jones.
A wind turbine comprises four main parts: the tower, nacelle, hub and blades. The nacelle is a weather cover housing all of the generating components in a wind turbine, including the generator, gearbox, drive train, and brake assembly.
Jones said while the assembly of the wind tower is not that complicated the logistics, planning, engineering and timing required to put the "giant puzzle pieces together" was the challenge.
"All tower lifts are a tandem lift and require two cranes. We use special grease and health and safety standards are followed to the tee. Basically we lower the one section on to the other, and this process is followed by bolt torqueing - done with specialised calibrated equipment at high pressure."
Following the tower construction is the assembly of the more complicated nacelle and hub section. The hub and blades are collectively known as the rotor.
"The planning and execution of the rotor lift has to be precise to ensure the 70 ton rotor, which is also 113 meters in diameter, is lifted properly. The higher you go, the windier it gets so this is really a critical exercise.
"The first nacelle lift had everyone on their toes - and the focus and complexity increases with each lift as you go up," said Jones of the first completed turbine on the Metrowind project.
According to Basil Read Matomo, South Africa is in a unique position to leap frog technologically with the national wind farm projects and construct 3MW wind turbines, rather than the older 1.5MW turbines.
"Not only are we able to use the most advanced wind turbine technology, but we are also engaging the experts worldwide, with consultants from Spain, Italy and China working with us here at Van Stadens to ensure the installation is efficient and safe."
Four consultants from Spain and Italy are present on site and bring with them the significant experience of establishing a number of wind farms in Europe. The four Chinese representatives are from Sinovel, the turbine manufacturing company.
The 27 megawatt (MW) Metrowind Van Stadens wind farm will comprise of nine Sinovel SL3000 3MW turbines and is expected to produce 80 000MWh per year, with installation to be complete by October followed by commissioning. Basil Read Matomo was awarded the R475-million contract late last year.