As the wind power industry strives for ever larger turbines on land as well as offshore, Siemens Gamesa is focusing on how to deal with the resulting transportation issues and how to split large components, recently appointed onshore technology head Jorge Magalhães told Recharge.
“Technically, there is no upper limit. That is certainly demonstrated by offshore,” Magalhães said when asked how big onshore turbines could become.
“It really is an economic trade-off decision. How are you going to deal with the logistical challenges for a specific geography?”
While some regions have less of those challenges due to a good access to ports or roads that are fairly wide, in other geographies logistical challenges to size and weight, or issues such as crane availability or crane heights matter more, he said.
Working on split-blade
In markets that are very constrained logistically in regards to space and size, splitting blades and the concept of breaking down turbines in to smaller pieces that can quickly be reassembled on site, could be one solution, according to Magalhães, speaking while the Wind TV digital conference during WindEnergy Hamburg was underway.
“Like all our core industry players, we have been looking at different options of how to transport and how to assemble a split blade. We have quite a bit of experience with a previous [Gamesa] model,” he said.
“We haven’t announced our split blade product yet, but we are working on one.”
Siemens Gamesa can draw from its vast experience in offshore wind technology when dealing with transport limitations, lifting techniques, minimising the use of cranes, especially larger ones, and the implications throughout the value chain, he said.
The OEM at the WindEurope exposition in Bilbao last year unveiled two 5.8MW turbines, its most powerful onshore machines so far. GE yesterday presented a 6MW model of its Cypress platform, also its largest so far, while Western rivals Vestas, Nordex and Enercon have also already broken through the 5MW-plus onshore barrier.
Enercon in the past also had offered a 7.5MW onshore model, which was last installed at the 90MW Zuidwester wind farm in the Netherlands in 2017.
But the German manufacturer discontinued producing the machine that saw few orders, probably due to transport constraints although cost may also have been an issue. The 12 turbines for Zuidwester, a wind farm adjacent to the Dutch Ijsselmeer Lake had been transported by vessels from manufacturing sites in Germany that were relatively close.
While Siemens Gamesa is not announcing any new model at WindEnergy Hamburg, it is looking at additional options for different markets as part of its modular approach to wind turbine development.
“Some of the areas in terms of options in the future relate to noise options, noise restrictions, and other market features we may deem necessary.”
The need for noise mitigation is quite market specific, the onshore technology head said, depending on population densities (which are rather high in Europe, for example) and the exact location of wind projects.
Siemens Gamesa is also eying the increasing repowering market in the context of larger or noise-reduced models.
“If you look at Germany, there are over 30,000 turbines that combined have an output of 50GW. If we were to replace those with our latest 5X machines, we would need a fifth of that, probably some 7,000 turbines,” Magalhães said.
“We could use less space for those, so the distance to the closest neighbourhood would increase. But also - although these turbines are bigger and potentially the noise from the air acoustic might be larger - we have a lot of mitigation possibilities in our new technology.”
Research on optimising output with minimal noise continues, to support already available options such as operating turbines in different modes for night time operations, that enable machines to run at reduced power at night when demand is lower.
Magalhães added that there are also other options that apply when turbines operate in more integrated networks, while hybrid solutions with turbines linked to storage or hydrogen production can also be an option.