PO094

Offshore wind cost of energy: what are the implications of very large turbines?

Simon Cox, Ben Chilvers, Fred Davison
DNV GL, Bristol, UK

Abstract

Recent offshore wind farm auctions in the Netherlands and Denmark have left many asking the question, how can a project be built at these significantly reduced strike prices? DNV GL explores how the next generation of 10+ MW wind turbines could contribute to a reduction in LCoE, enabling more competitive projects with reduced strike prices and potentially subsidy free projects in the future.

This work explores the potential size and performance of next generation turbines based on detailed modelling using the Bladed wind turbine simulation software. Then how the loads from the turbine impact the turbine support structure design and costs using Turbine.Architect advance modelling. Finally, the impact of the next generation turbine on installation and O&M is assessed using Construction planning (O2C) & Operations planning (O2M) software. Enable a detailed analysis of the impact of the next generation turbine on project CapEx & OpEx.

An offshore wind farm is modelled using the next generation wind turbine in the WindFarmer wind farm design software to enable the impact of 10+ MW turbines on layout design and wind farm energy yield to be analysed.  The yield is then combined with the costs to calculate the impact on Levelized Cost of Energy.

The results of the work highlight the technical challenges that arise from increasing turbine size, the potential impact this has on turbine support structures and wind farm design. Posing an answer to the question, is bigger always better for offshore wind turbines?

Method

Detailed modelling of wind turbine loads and power curve based on the Bladed wind turbine simulation software will be used to estimate the size of the next generation of wind turbines, based on analysis of key compliments, including; blades, drivetrain, generator and control system.

Integrated design based on turbine loads is used to optimise tower and support structure to understand how large turbines impact costs of turbine support structures.

Turbine.Architect tool, Construction planning (O2C) & Operations planning (O2M) software are used to estimate the impact of on wind farm CapEx & OpEx.

WindFarmer wind farm design tool is used to enable the wind farm layout and energy yield to be estimated and combined with CapEx & OpEx to calculate the impact on Levelized Cost of Energy.

Results

10+ MW turbines are achievable using current technology and the cost per MW is expected to rise significantly for these turbines compared to 6-8 MW turbines.

Turbine support structures are achievable for next generation turbines with a reduction in the cost per MW.  Additional reductions in the cost per MW of Balance of Plant, construction and O&M have been modelled.

The resulting impact on wind farm energy yeild and LCoE is still work in progress, with results expected soon.

Conclusions

Offshore wind farm developers are working hard on their strategies to win the next auction, this paper gives them an insight into what the next generation turbine will look like, how they will performance, how turbine support structures need to change and the impact on the whole project.

At this stage Turbine OEMs have not announced detailed and this paper will give certainty to, developers, vessel operators and the supply chain as to what is coming next. Enabling the offshore wind industry to realise cost reductions.

Objectives

Do larger offshore wind turbines results in lower LCoE?

What are the risks in larger wind turbines?

How do larger turbines impact turbine support structures?

Will installation methods and O&M need to change to account for large wind turbines?

How will wind farm layouts change with larger wind turbines?