Denmark’s Vestas has unveiled a 3MW version of its next-generation EnVentus concept, a design that nestles neatly between the OEM’s highly regarded 2MW and 4MW onshore platforms, but also marks a symbolic departure for the company as it transitions from being a pure-play wind turbine manufacturer toward a future as an energy solutions provider

The V138-3.0 – a modular machine that will churn out up to a 34% higher annual energy production (AEP) than its smaller cousin – will fly 67-metre-long single-web, structural-shell blades powering a medium-speed drive-train with permanent magnet generator and full-power converter.

Yet it is its inner componentry – which shares “all major functional and physical designs” with that of the giant 5.6MW model launched to great fanfare earlier this year – that points to where Vestas sees turbine architecture going.

Bigger may be better in pure nameplate terms, but modularity increases the “flexilbility [of the concept] while maintaining benefits of scale”, chief technology officer Anders Vedel tells Recharge. Vedel says that along with allowing for “more customised solutions” for developers and the potential to expand the number of models while lowering the waybill of components, the design will also streamline supply chain deliveries.

“The modular architecture plays through the total value chain and complete life-cycle,” he states. “It starts with the design and testing process. Rather than focusing on the turbine platform variant as such, we go down and focus on the modular level.

“We take into consideration the requirements of the market and the customers, and the potential to improve the performance of our product within a certain envelope with a certain volume, and then we look at which modules will help us achieve the necessary enhancements,” says Vedel, who notes that Vestas has now merged its engineering and platform management functions into one, as “Modular Product Development”.

By breaking down the “linearity” of turbine platform technology development to the module-level, he argues, individual components can effectively be tested once and then assembled at different scales, a shift in approach that “carries through logistics of manufacturing and warehousing, for instance, and transportation and so on”.

“And then when it comes to servicing [of these turbines on an operational wind farm], modularity has its advantages too for our technicians, who will be working on what are 80-90% the same turbines as far as their functionality goes, irrespective of their size,” Vedel adds.

The Danish OEM sees the design philosophy embodied by the EnVentus concept as key to arming it to confront unrelenting customer demand for cost reduction in a post-subsidy, auction-driven energy market – benchmarked against solar power's ever-lower levelised cost of energy (LCOE) – while upping its own commercial performance.

“The change that we are undertaking [from being a supplier of wind turbines] to being a supplier of sustainable energy solutions – it is a natural step,” says Vedel. “And the modularity similarly is a necessity if we in wind power want to continue to drive efficiencies that will make us competitive in [terms of] the energy price.

One of the main drivers of lowering LCOE is adapting a turbine to the needs of a site or a market.

“And let’s not forget: one of the main drivers of lowering LCOE is being able to adapt a turbine to the specific requirements of a site – or indeed a market. ‘Right sizing’ is very important.”

Post-PTC US market

Nowhere is this more the case than in the US, where developers – and so OEMs – are facing a market that will lose the underpinning of production tax credits (PTC) after 2021. It is also a market with limiting tip-height requirements, making it impossible to sell turbines with wingspans the size of the 5.6MW’s 162-metre-diameter rotor.

The V138-3.0 blades will sweep an industry-leading 14,957 square metres, while squeaking under the 500ft tip-height restrictions imposed in the US when set atop an 83-metre tower. But more importantly, it will do so while delivering a “very high” capacity factor in low wind speeds of 6.5-8.5 metres per second, notes Vestas Americas president Chris Brown, in a “super LCOE-focused market”.

“This turbine is a key piece in how we are looking to further drive down the LCOE,” he tells Recharge. “When we are thinking about what the PTC has done to incentivise renewables – and will soon no longer do – we need a ‘bridge’. And that ‘bridge’ needs to be under the 500ft tip-height restriction.” He called the new machine a “perfect match” for the changing US market.

“The V138-3.0 has the largest rotor-to-generator ratio that fits spatially in the US,” states Brown, adding that the 3MW EnVentus’ “particularly large gear-box” gives it a very low rotational speed – below 11 revolutions per minute – that translates into less rotor fatigue and lighter loads and more torque at a lower cost.

Brown points to the step-up in size of wind farm in the US as it approaches the end of the PTC era, “from where 200MW was standard to where 500MW is”, as strengthening the case for a 3MW turbine over a 2MW model.

“Developers are still asking themselves ‘can I swallow 500MW at a time [due to the financial exposure]?’ – but this product sits right in the sweet spot because you can use fewer turbines and still get the big installed capacity at lower risk.”

Vedel adds: “While it is difficult to accurately predict what the post-PTC era's market dynamics will be, to deliver a turbine that produces at this much higher AEP than the 2MW and one that can also fit in under the current tip-height restrictions, means we believe [the V138-3.0] will have a strong market position.”

Brown continues: “And we are looking beyond 2021 – where many [other companies] are focused just on the next few years. We want the industry to raise it sights and think about the sustainability of the [wind power] market beyond that.

“Thinking about it as a ‘cliff’ as we were doing years ago is old hat. This is a ‘transition’ to not a commodity market, but certainly [to] a more competitive market in the broader sense [including competing with solar]. The product could fit well with hybrid [wind-solar-storage] projects too.”

Though launched this week with the US market in its cross-hairs, Vedel underlines that the 3MW EnVentus will be a “global” turbine suitable to “anywhere in the world where there are megawatt constraints”.

A prototype of the V138-3.0 is slated to be up and running in the second half of 2020 at the Danish national test centre at Høvsøre, with serial production starting at the OEM’s factory in Pueblo, Colorado in Q2 2021 and first orders to follow.

Wind

Vestas launches 3MW EnVentus as post ‘pure-wind’ future beckons