Comparison of Operation and Maintenance of Floating 14 MW Turbines and Twin 10 MW Turbines

Abstract

Turbine ratings in the past decade have grown unexpectedly fast. In 2021, Siemens Gamesa and GE revealed their new 14 MW turbine models, and it is predicted that this is not yet the rating limit that turbines can reach. Increased turbine ratings can also be achieved by putting two turbines on a single foundation. This study analyzes how operation and maintenance (O&M) would differ if a floating wind farm had twin 10 MW turbines installed on each substructure, instead of a single 14 MW turbine. This study demonstrates how the strategic O&M simulation tool compass can be used to perform this comparison. Assumptions regarding the O&M of twin turbines were estimated with the major floating twin turbine developer Hexicon AB. This study analyzed four cases—a case with 35 twin 10 MW turbines, and three cases with 50 single 14 MW turbines—to understand the potential effect of increased consumable costs, spare part lead times, and maintenance durations. All cases had the same wind farm capacity of 700 MW. The results show that O&M for cases with single turbines is at least 4.5% more expensive than the case with twin turbines. The case with twin turbines also resulted in a higher availability than any other case. Additionally, results showed that operational expenditure (OPEX) for the cases with single turbines is at least 6.0% higher in scenarios with single turbines than in the twin turbine scenario. The biggest cost contributors to the difference between scenarios were craft costs, particularly cable laying vessels and tugs. Due to the higher number of cables required for the scenario with single turbines, there is more frequent mobilization of cable vessels for cable repairs.

Life Cycle Assessment of Four Floating Wind Farms around Scotland Using a Site-Specific Operation and Maintenance Model with SOVs

“…This study was completed in response to these opportunities, as an LCA of a 15 MW reference wind turbine, developed by the National Renewable Energy Laboratory (NREL) and the International Energy Agency (IEA). Here, these turbines have been considered as forming four very large floating wind farms, located in the ScotWind leasing round, using a mix of HVAC and HVDC transmission systems, using data from a dedicated O&M model, COMPASS [29]. The O&M modelling and other foreground data have been prepared with expert input from the Offshore Renewable Energy (ORE) Catapult in Glasgow, Scotland.…”

“…COMPASS is a strategic O&M simulation tool which can model the full lifetime of a wind farm and estimate key performance indicators associated with its operation [29]. The energy production used in the environmental impact calculation is taken from the availability modelling from COMPASS.…”

Towing Analysis and Validation of a Fully Assembled Floating Offshore Wind Turbine Based on an Experimental Study

“…The Windfloat Atlantic, Hywind Scotland, Kincardine and Hywind Tampen projects utilised towing vessels and operations during their construction [3,4]. Tow-to-port and tow-to-shallow operations are planned for major maintenance activities for Kincardine and Hywind Scotland wind farms, respectively [5]. During a heavy maintenance campaign at the Kincardine wind farm, one of the platforms was detached from the mooring system and towed to a maintenance port and subsequently towed back to the wind farm location after necessary repairs [6].…”