Wind Turbines (Offshore)

Wind Turbines (Offshore)

Project Drawdown defines wind turbines (offshore) as: offshore utility-scale wind power technologies. This solution replaces conventional electricity-generating technologies such as coal, oil, and natural gas power plants.

Offshore wind solutions are increasingly being adopted where wind is less intermittent and the turbines can harvest more energy. The offshore placement increases construction and grid connection costs due to the more remote location, and requires increased investment to protect equipment from the ocean environment, but the capacity factors of offshore turbines are often higher than onshore turbines. Modifications include: upgrades to the support structure so it can withstand added loading from waves; pressurized nacelles; and environmental controls to prevent corrosive sea air from degrading electrical components.

Since the amount of power generated by a wind turbine is primarily determined by its size and the intensity of the wind resources, offshore locations are a growing opportunity. By the end of 2015, there were an estimated 3.4 gigawatts of installed offshore wind systems connected to the grid, mainly in Europe and China.

Methodology

This analysis models offshore utility-scale wind power technologies.

Total Addressable Market [1]

The total addressable market for wind turbines (offshore) is based on projected global electricity generation in terawatt-hours from 2020-2050, with current adoption [2] estimated at 0.11 percent (i.e. 25 terawatt-hours) of generation (IRENA, 2016b).

Adoption Scenarios [3]

Impacts of increased adoption of wind turbines (offshore) from 2020-2050 were generated based on three growth scenarios, which were assessed in comparison to a Reference Scenario where the solution’s market share was fixed at the current levels.

• Plausible Scenario: Based on the evaluation of six global energy systems models, [4] this scenario follows a high growth trajectory, capturing 4 percent of the electricity generation market share in 2050.
• Drawdown Scenario: This scenario follows a more aggressive adoption pathway aligned with the growth rate proposed by the Greenpeace [R]evolution Scenario, resulting in a 5.83 percent share of the market in 2050.
• Optimum Scenario: This scenario follows the Greenpeace Advanced Energy [R]evolution Scenario, [5] resulting in a 6.08 percent shares of the market in 2050.

Financial Model

The financial inputs used in the model consider an average installation cost of US$3,940 per kilowatt, [6] with a learning rate of 15.9 percent, resulting in first costs of US$2,018 per kilowatt in 2030 and US$1,441 per kilowatt in 2050 (Hayward and Graham, 2013). An average capacity factor of 34 percent is used for offshore wind turbines, compared to 55 percent for conventional technologies such as coal, natural gas, and oil power plants. Variable operation and maintenance costs of US$0.073 per kilowatt-hour are considered for offshore wind, compared to US$0.005 per kilowatt-hour for the conventional technologies.

Integration [7]

Through the process of integrating wind turbines (offshore) with other solutions, the total addressable market for electricity generation technologies was adjusted to account for reduced demand resulting from the growth of more energy-efficient technologies, [8] as well as increased electrification from other solutions like electric vehicles and high-speed rail. Grid emissions factors were calculated based on the annual mix of different electricity generating technologies over time. Emissions factors for each technology were determined through a meta-analysis of multiple sources, accounting for direct and indirect emissions.

Results

The results for the Plausible Scenario show that the net cost compared to the Reference Scenario would be US$572.4 billion from 2020-50, and around US$274.57 billion in savings over the same period. Increasing the use of offshore wind from about 0.11 percent in 2014 to 4 percent of world electricity generation by 2050 would require an estimated US$1,359.8 billon in cumulative first costs. Under the Plausible Scenario, offshore wind turbines could reduce 14.1 gigatons of carbon dioxide-equivalent greenhouse gas emissions from 2020-2050.

Both the Drawdown and Optimum Scenarios are more ambitious in the growth of offshore wind technologies, with impacts on greenhouse gas emission reductions over 2020-2050 of 16 gigatons carbon dioxide-equivalent and 19.7 gigatons carbon dioxide-equivalent, respectively. Our projections consider that much of the growth in offshore wind will take place in China, where costs will likely be lower.

Discussion

Benchmarks

The results of the Plausible Scenario are more ambitious than those of the 2°C Scenario of IEA ETP (2016), which estimates the growth of offshore wind to reach 3.1 percent of the market in 2050. Compared to the Greenpeace Energy [R]evolution Scenario, however, our results for adoption are nearly half, with electricity generated from offshore wind turbines representing up to 8 percent of the market in 2050 (Greenpeace, 2015).

Conclusions

Wind power plays a large and essential role in any long-term projections toward a low-carbon future: wind has large megawatt capability, is globally available, and the output of wind and solar is complementary in many regions of the world. As a renewable resource, wind does not require mining or drilling for fuel, and its costs are therefore not susceptible to fluctuations in fossil fuel prices.

The growth of offshore wind could be aided by renewable energy and portfolio standards that mandate a certain level of renewable use. Wind developers could also benefit from regulatory stability, such as feed-in-tariffs that guarantee a certain rate of return on wind energy, and tax incentives that encourage investment in low-carbon projects like wind by helping offset development costs. Public research and development, particularly for this immature technology, can also help decrease costs. Technology knowledge transfer could help spread wind power across borders.