Repowering projects and the wind power value chain

In short

In a July blog post, we outlined a simplified overview of the wind power value chain. However, it’s essential to distinguish between greenfield and repowering projects. In repowering initiatives, the decommissioning of existing wind turbine generators (WTGs) at their end-of-life (EoL) is often overlooked, despite it being a vital step in facilitating the addition of new wind power capacity. In this article, we explore the key role that WTG decommissioning plays in the growth of wind energy through repowering projects.

The role of repowering within the wind power value chain

In Germany alone, over 10,000 WTGs are approaching the end of their expected life cycles. Repowering involves replacing these aging turbines with newer models that provide cutting-edge performance. Technological advancements in wind power over the past few decades have significantly increased both nameplate capacity and cost efficiency, making it increasingly economical to replace outdated equipment – sometimes even before it has fully exhausted its service life. For instance, modern turbines with power ratings exceeding  5 MW are now replacing older models that typically had power ratings below 1.0-1.5 MW. 

Unlike greenfield developments, existing wind farm sites are often well-suited for upgrades because they benefit from public acceptance, streamlined permitting processes, and established grid infrastructure. Decommissioning older WTG systems opens up high-yield sites for the installation of newer, more powerful systems with higher nameplate capacities, facilitating deployment that might not be feasible otherwise. This process transforms wind farm repowering into a circular model, where the costs associated with decommissioning old WTG systems are integrated into the installation of new ones, therefore creating a sustainable value chain (see below). 

The net impact of decommissioning & repowering

Replacing still-operational WTG systems may raise concerns about potential material waste and the loss of output from these turbines, which could negatively affect the climate impact performance of the repowered WTG fleet. However, the validity of such concerns is limited. 

To begin with, the “carbon debt,” or cradle-to-gate carbon footprint, of new WTG systems is typically repaid within a relatively short time frame. For instance, Vestas estimates that its V117 4.2 MW turbine will achieve “energy neutrality” in approximately 4.8 months. Additionally, the average lifespan of decommissioned WTG systems in Germany is about 21 years. Even if newer wind turbines are capable of longer operation, the energy output of repowered fleets during this period usually far exceeds that of the older turbines. Crucially, this increased energy production occurs sooner than it otherwise would have with the older models. 

Finally, a significant portion of materials and components from decommissioned WTG systems can be reused, refurbished, or recycled – currently about 96% of a wind turbine is made of recyclable materials. This potential  is even more effective when supported by well-designed regulatory incentives and mandatory standards. Refurbishing or reusing components, or even entire WTG systems, particularly in emerging economies, also plays a crucial role in accelerating the decarbonization of the local electricity mix. 

Now what?

Repowering offers significant benefits from both an environmental and economic standpoint. Decommissioning outdated WTG systems transcends mere waste management; it paves the way for replacing aging equipment with newer, technologically advanced models. Companies like neowa, which specialize in providing the necessary resources and expertise for safe and efficient WTG decommissioning, play an important role in the EU’s energy transition. By increasing the rates of reuse, recycling, and refurbishment, they contribute to minimizing the ecological footprint of decommissioning while amplifying its positive impact.