Status: this preprint is currently under review for the journal WES.
Economic Viability of Floating Offshore Wind in Portugal with Varying Market Conditions and Financial Support Mechanisms
Craig White,José Cândido,and Ciaran Frost
Abstract. This studyassessesthe economic viability of commercial scale floating offshore wind farms in Portugal, under a range of CfD mechanisms. A techno-economic model was created to create synthetic range of time series wind and spot price data that creates financial revenue under varying CfD types, water depths, and distances to shore. Results are split into levelized cost of energy, net present value, and internal rate of return and are influenced by a range of sensitivity analyses that help define the financial setting for successful floating offshore wind projects, including CfD mechanisms varying in type, value and duration. Results show promise for the development of floating offshore wind but only under strong financial support and are heavily influenced by site, wind regime and economic conditions.
Received: 09 Nov 2025 – Discussion started: 10 Dec 2025
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This paper describes the techno-economic potential of floating offshore wind in Portugal under various financial scenarios. Overall, the authors do a great job of describing the variables that were measured, the inputs, assumptions, and sensitivities for the model, and the three distinct Contracts for Difference (CfD) scenarios. The authors also clearly describe the results and the interpretation of the individual results (although many of the figures could be updated for readability). However, the conclusion/discussion is underdeveloped and can benefit from re-iterating the broader significance of the findings as well as the study’s limitations.
Specific Comments
The paper does a great job of what is being modeled and where, but I am curious of how the modeling was performed. How scalable is the model? Is it reproducible? What are the uncertainties and limitations? Has something like this ever been modeled before for this technology and location, or is this a novel analysis?
Also, the authors should make sure that every data source is listed, especially for the cost data. What are the assumptions for the base case (for CAPEX, OPEX, etc.)?
Lastly, the conclusion needs to be enhanced to include the broader significance of the findings, or at least the broader significance of the technology. Who benefits from this technology over others? Are there comparable studies for other technologies such as fixed offshore wind, and if so, how do the results compare? How can the results inform specific decisions (regarding siting or leasing, for example) moving forward?
Specific areas that need clarification:
Lines 39-41: “Notwithstanding the lower costs of onshore wind and solar, (Silva & Sareen, 2021) argue that public attitudes vary, with community opinions and engagement often overlooked or bypassed, which presents an opportunity for floating wind development.” I’m not sure what this means; how does it present an opportunity for floating wind development?
Lines 161-162: “This method was applied to twelve locations, each at three distances to shore, to provide a comprehensive feasibility study for the whole of Portugal.” This was a bit confusing; I would clarify that the method was applied to twelve regions, each at three distances to shore, for a total of thirty-six distinct locations.
Lines 298-299: “Geographical features including Sintra peninsular off Lisbon and also in the Southwest, Sagres zones also benefit from improved but local windspeeds.” Confusing text.
Figure 4: Why is the LCoE so much higher in the further sites in Sagres West compared to Sagres South? It seems like they are following the same windspeed/depth patterns, but there could be some variation in the data that I'm not seeing in this figure.
Lines 353-354: Name the “selected few sites” viable under current economic conditions.
Line 375: Was a sensitivity analysis shown for IRR?
Technical Corrections
Line 88: “The main function of LCoE is as an evaluation metric…” Simplify text to something like "LCoE is an evaluation metric...”
Line 190: Define FID.
Lines 229 -230: “The model also contains a timeseries generator, which creates random timeseries for both windspeed and spot price data, and respects the statistical properties of the original.” Reword sentence to fix grammar.
Figure 2: Reference figure in the text and identify the unit of measurement for "time step" on the x-axes.
Line 242: Typing error (“nes”).
Figure 3 and Figure 4: Increase resolution of images.
Figure 6: It would be helpful to have this figure next to Figure 5 since they are showing the same information just in a different format. Maybe also order the Sites from North to South as opposed to alphabetically so they are easy to compare side-by-side.
Figure 8: Although the overall trend is clear, it's hard to decipher the individual lines.
Figure 10: Move PAER Zones layer so that it's underneath the sites and labels in the maps for better readability.
This paper presents a realistic assessment of the economic case for floating offshore wind development in Portugal. The site of one of the first demonstrator projects but as yet still to develop into commercialisation. Updated costs and CfD revenue mechanisms assess the current economic performance and are presented with a range of maps that aim to clearly show which areas show promise and which may bring more challenges.
This paper presents a realistic assessment of the economic case for floating offshore wind...
General Comments
This paper describes the techno-economic potential of floating offshore wind in Portugal under various financial scenarios. Overall, the authors do a great job of describing the variables that were measured, the inputs, assumptions, and sensitivities for the model, and the three distinct Contracts for Difference (CfD) scenarios. The authors also clearly describe the results and the interpretation of the individual results (although many of the figures could be updated for readability). However, the conclusion/discussion is underdeveloped and can benefit from re-iterating the broader significance of the findings as well as the study’s limitations.
Specific Comments
The paper does a great job of what is being modeled and where, but I am curious of how the modeling was performed. How scalable is the model? Is it reproducible? What are the uncertainties and limitations? Has something like this ever been modeled before for this technology and location, or is this a novel analysis?
Also, the authors should make sure that every data source is listed, especially for the cost data. What are the assumptions for the base case (for CAPEX, OPEX, etc.)?
Lastly, the conclusion needs to be enhanced to include the broader significance of the findings, or at least the broader significance of the technology. Who benefits from this technology over others? Are there comparable studies for other technologies such as fixed offshore wind, and if so, how do the results compare? How can the results inform specific decisions (regarding siting or leasing, for example) moving forward?
Specific areas that need clarification:
Lines 39-41: “Notwithstanding the lower costs of onshore wind and solar, (Silva & Sareen, 2021) argue that public attitudes vary, with community opinions and engagement often overlooked or bypassed, which presents an opportunity for floating wind development.” I’m not sure what this means; how does it present an opportunity for floating wind development?
Lines 161-162: “This method was applied to twelve locations, each at three distances to shore, to provide a comprehensive feasibility study for the whole of Portugal.” This was a bit confusing; I would clarify that the method was applied to twelve regions, each at three distances to shore, for a total of thirty-six distinct locations.
Lines 298-299: “Geographical features including Sintra peninsular off Lisbon and also in the Southwest, Sagres zones also benefit from improved but local windspeeds.” Confusing text.
Figure 4: Why is the LCoE so much higher in the further sites in Sagres West compared to Sagres South? It seems like they are following the same windspeed/depth patterns, but there could be some variation in the data that I'm not seeing in this figure.
Lines 353-354: Name the “selected few sites” viable under current economic conditions.
Line 375: Was a sensitivity analysis shown for IRR?
Technical Corrections
Line 88: “The main function of LCoE is as an evaluation metric…” Simplify text to something like "LCoE is an evaluation metric...”
Line 190: Define FID.
Lines 229 -230: “The model also contains a timeseries generator, which creates random timeseries for both windspeed and spot price data, and respects the statistical properties of the original.” Reword sentence to fix grammar.
Figure 2: Reference figure in the text and identify the unit of measurement for "time step" on the x-axes.
Line 242: Typing error (“nes”).
Figure 3 and Figure 4: Increase resolution of images.
Figure 6: It would be helpful to have this figure next to Figure 5 since they are showing the same information just in a different format. Maybe also order the Sites from North to South as opposed to alphabetically so they are easy to compare side-by-side.
Figure 8: Although the overall trend is clear, it's hard to decipher the individual lines.
Figure 10: Move PAER Zones layer so that it's underneath the sites and labels in the maps for better readability.
Line 377: Typing error (“o”).