Offshore Wind Energy
Abstract
This paper provides an overview of the offshore wind energy industry, how effective way is this and as a renewable energy technology that will be needed to make world better place. It provides a new perspective to the people who thinks the wind is not an effective way to generate energy. The paper provides that why the offshore power is important and has a huge potential to become the main resource of the world’s energy. Offshore wind power has been using in the Europe since the beginning of the 1990s and in the USA since the beginning of the 2000s. The industry is driven by the European countries, especially the North of the Europe. This paper covers both technical, economical and natural effects of offshore wind power basically and deals with a brief result of using renewable energies and also the increasing demand of the renewable energy. The paper is also based on the differences between the offshore wind energy and other renewable (mostly onshore wind energy) and non-renewable energies.
Keywords:
- Renewable Energy
- Wind Power
- Offshore Wind Industry
Introduction
The global energy sector is changing towards renewable energy and the countries prefer these renewable resources more than ever nowadays, especially wind power growing exponentially for the last 30 years. The increasing use of renewable energy have a positive impact on the offshore wind energy market. Wind power is one of the best solutions for global warming and environmental pollution. Onshore wind turbines are limited because of being installed near to the places where people live, and it is difficult to produce electricity efficiently. Offshore wind farms have higher capacity and they are more effective way to produce electricity compared to the onshore wind farms, because of several factors like they designed for higher wind speed, no limitation because of constructed in middle of the oceans which means no human lives nearby, as a result of using deeper waters; less land uses, no public, and offshore farms can also reach higher power because of its taller and larger turbines.
All wind turbines operate with the same process. As the wind blows, it flows to the blades of the turbine and causing the blades to spin. That blades are set up the shaft and by way of the drive shaft the electricity is produced.
Market
Wind power is the 18% of the Europe’s total power capacity, and it was 12% in the end of the 2012. Europe installed wind power capacity is also increased up 25% over 2016, bringing its total capacity 168 GW. 16 GW of them is offshore wind power. The EU market is dominated by the two countries, Germany and United Kingdom, with 80% of the Europe’s newly installed capacity.
Turkey is one of the potential countries for wind power, among the top 10 country with a total capacity of 6.9 GW. According to Turkish Wind Energy Association, Turkey added 1,387.75 MW in 2016 for a total of 6,106.05 MW and added 766.05 MW in 2017 for a total of 6,872.1 MW. [1]
According to the National Strategy report in the U.S coastal areas, offshore wind farms could reach an installed capacity of 3GW of power by 2020, an installed capacity of 22GW of power by 2030, and an installed capacity of 86GW of power by 2050. The report also suggests that as much as 12TW could be delivered by offshore wind energy by 2020, 87TW by 2030, and 339TW by 2050.
Asian countries have also major role in the wind power, heading from China. China’s offshore wind power adventure has started in 2017, and they installed 2.8 GW capacity and planned to have 5 GW by the end of 2020. Even Europe is still dominating the wind energy industry with global offshore capacity of 84%, it was 88% in 2016. This downfall is a result of Asia’s exponential growth of the offshore wind industry, under the leadership of China.
Wind Industry
Wind power is the new favorite energy producing way for many reasons. Including new technologies and innovations which includes larger rotor sizes, longer blades and so on, lower costs, lower risks and many other economic and technical reasons. The size of the turbine and the costs are inversely proportional. Larger turbines mean that fewer resources are required for the same output, and that means lower risks, lower operation & maintenance costs, and as a result of them higher profitability. “Therefore, the utilities can save large costs by ordering larger wind turbines because at the same time they need to purchase fewer foundations, pull fewer cables and fly out to fewer turbines for maintenance. In offshore business, big is beautiful and the sky is still the limit.” says Peter Nyegaard Jensen, Head of Sales, The Switch, Denmark.
Even non-wind companies no matter they are public or private corporations are also moving further into the wind industry. Large oil & gas companies Shell, Total, Statoil etc. which are the companies are currently working on oil industry try to be inside of the wind sector, especially offshore.
Technology
There are different types of design and technological methods are using in the offshore wind industry to have greater profitability, minimizing costs, take more advantage from resources etc. The installation is a difficult and complex part of the technology. There are different types of foundations. Basically, foundations can be classified as fixed foundations and floating offshore wind technology. Most of the current offshore wind farms are installed fixed foundations, floating foundations are the new technology.
Fixed Foundations
There are three types of fixed foundations: Monopiles, Gravity Structures, and Tripod Structures.
Monopile is the simplest structure of fixed foundation. Monopiles are used when the depths are 15 meters. There is a single tile which made up of a thick steel directly anchored to the sea ground.
Gravity base structures, concrete or steel with diameter of 15 meters, are using when the depth is around 30 meters and involves using weights up to 1000 tons.
Tripod structures are consisting of three or four anchoring points and they are using in deeper waters, when the depth is greater than 60 meters.
Floating Offshore Wind Turbines
The significant advance of the offshore wind sector is the floating turbines. Floating turbines are the turbines that are not riveted to the ground of the sea, and because of that they expand the areas and can be placed where the winds are the strongest. The floating turbines are located where the wind is more useful rather than where the seafloor is suitable.
The economic return of the floating wind turbines were more than the experts expected. According to Beate Myking’s statement after the world’s first floating offshore wind farm has installed in Scotland: “Hywind Scotland’s high availability has ensured that the volume of electricity generated is substantially higher than expected. In addition, it has delivered without any HSE incidents,” says Beate Myking, senior vice president of offshore wind operations in Statoil.
Discussion — Onshore vs Offshore
The market is dominated by onshore wind turbines since the firs wind turbine was constructed in the late 1800’s. However, the countries and the companies are trying to implement offshore wind turbines nowadays.
Why Onshore?
Offshore turbines can produce more electricity, but these turbines can be more expensive than onshore turbines.“Onshore wind is the cheapest form of new build electricity generation available in the UK today, and statistics show that it is supported by over three-quarters of the British public. The Government can benefit from cheap, green and clean energy to deliver the Industrial Strategy and Clean Growth Plan by supporting onshore wind as well.” said Caroline Lucas, Member of Parliament of the United Kingdom.
Here is a list of onshore wind turbine’s key advantages:
- Onshore wind turbines are less expensive than offshore turbines.
- These turbines are also the cheapest way of produce electricity compared to all the other renewable sources such as solar, hydroelectric etc.
- Since the turbines are being placed in the land, no more transportation costs needed.
Why Offshore?
There are many different reasons that the countries are trying to use offshore wind turbines. Policy supports, greater profitability, no risk of visual impact and a maturing supply chain makes offshore wind better option to produce electricity. “The main difference between onshore and offshore wind installations is on their respective environment, which are much more complex in the sea not only for the design but also for the construction and operation works, because of the significant increase of the factors that can condition all of them. The first advantage is the better quality of the wind resource in the sea, where wind speed is usually bigger, even increasing with the distance to the coast, and more uniform (softer), leading to less turbulence effects; therefore, the fatigue is less important and let to increase the lifetime of the offshore wind turbine generator. The second advantage becomes from the bigger suitable free areas in the sea where offshore wind farms can be installed, leading to greater installations. Its placement (far from population areas) lets to reduce the environmental regarding the noise emission, nearly all related with the increase of the blade-spit speed.”[2]
Here are some of the key reasons:
- Offshore wind farms are more efficient than onshore as wind is more useful and consistent in the middle of the oceans.
- Turbines can be built much larger and higher, therefore more electricity can be produced.
- Floating foundation offshore winds can be placed where the wind is more efficient, and these turbines can produce electricity with higher capacity.
- There is no physical restriction in the locations where the turbines constructed.
Environmental Impact
Wind power is one of the best green energy solutions to the future of world and humanity. In contradiction to the traditional sources of energy such as oil, gas and petrochemicals, offshore wind farms as any other renewable energy source, do not emit any greenhouse gasses or any pollutant effluents during when electricity is produced with this wind farms.
The environmental impacts of offshore wind turbines are mostly positive because of its renewable source that can help reduce carbon emissions, but its construction and operating could be a treat for the marine species.
“As the number and size of offshore wind developments increases, there is a growing need to consider the consequences and cumulative impacts of these activities on marine species,” said Helen Bailey, lead author and research assistant professor at the University of Maryland Center for Environmental Science’s Chesapeake Biological Laboratory. “It is essential to identify where whales, dolphins and other species occur to help avoid adverse impacts and to continue to monitor their response to the construction and operation of wind turbines.”
Pile driving is the most commonly used method in the construction phase. The sound during the pile driving could cause a hearing damage and the animals would move out of the area to avoid the noise. Because of producing electricity, there is an electro-magnetic field will be around the farm. The animal also wants to run away from the area where they own.
“A critical element of wind energy planning is developing projects in such a way that we avoid or minimize negative environmental impacts those installations may cause,” said Tom Miller, director of the University of Maryland Center for Environmental Science’s Chesapeake Biological Laboratory.
However, there is a great potential in the offshore wind power against the global warming, carbon emission, greenhouse gas emission, air pollution, and any other pollutions. Despite this, the offshore wind farms could be a treat for the marine species. Since the offshore wind power is using for approximately 20 years, the environmental effects researches of the offshore farms are even still in progress.
Conclusion
As the world is going to the point of no return, the renewable energy sources are the new favorites. The wind power is one of the most useful, sustainable and satisfying one because of several reasons like economic rate of return, environmental impacts, place of construction etc. There are two ways to produce electricity by using the wind, onshore and offshore. As the higher capacity to produce electricity, no land limitations, height of the turbines, offshore is the more effective way to produce compared to the onshore.
Offshore wind industry grows dramatically. According to a market research firm Global Insight’s new market report, the offshore wind energy market size will exceed USD $60 billion by 2024[3]. Europe is the leader of the offshore wind power with 84% of the world’s in operation capacity as October 2018 with approximately 17.5 GW of the 20.9 GW [4]
Wind is on the target for most of the companies and countries. Even non-wind companies want to be inside of the offshore sector. There are lots of reasons that the countries and the companies want to be have these turbines includes both technologically and innovative developments such as bigger rotor sizes, higher turbines, larger blades etc. There are different types of design and technological methods are using in the offshore wind industry to minimize the costs and maximize the revenues. Floating offshore wind turbines are one of the design innovations. These turbines are moving in the oceans and they have better potential to produce electricity. Floating turbines can be placed where the wind is more effective to use, and consequently they can be more productive have greater profitability.
Even the market is dominated by the onshore turbines since the first one was constructed in the 1800’s, the countries and the companies are now on the way for offshore because of its potential to be more effective and productive.
Finally, since the oils, gasses, nuclear power and other non-renewables are caused to green power and carbon emission, global warming, air pollution etc. renewable energy sources are more preferred nowadays because of its environmental impacts. Wind is one of the cleanest and environmentally friendly option to be used. Wind power as any other renewable energy sources, do not any pollutant effluents during when electricity is produced.
References
[1] from Turkish Wind Energy Association, Türkiye Rüzgar Enerjisi Istatistik Özet Raporu (Ankara: January 2018), p. 4, http://www.tureb.com.tr/ files/tureb_sayfa/duyurular/2018/02_subat/turkiye_ruzgar_ enerjisi_istatistik_ozet_raporu.pdf; added 766 MW in 2017 for a total of 6,857 MW, from WindEurope, op. cit. note 11, p. 9; added 766 MW for a total of 6,871 MW, from FTI Consulting, op. cit. note 1, p. 50; added 900 MW for a total of 6,981 MW, from WWEA, op. cit. note 1.
[2]Esteban M. D., Diez J. J., Lopez S. J.,“Why Offshore Wind Energy”February 2011, retrieved from: https://www.sciencedirect.com/science/article/pii/S0960148110003332#bib13
[3] from Global Insights Inc., Offshore Wind Energy Market Report 2018–2024, retrieved from: https://www.gminsights.com/industry-analysis/offshore-wind-energy-market
[4] from Statista, Offshore wind power plants — capacity by country 2018, “Capacity of offshore and near shore wind turbines in operation and under construction as of October 2018, by country (in megawatts)”, Retrieved from: https://www.statista.com/statistics/264264/capacity-of-offshore-wind-power-plants-worldwide-2010/
BSH, 2011. Offshore wind farms Measuring instruction for underwater sound monitoring, Current approach with annotations Application instructions,
http://www.bsh.de/en/Products/Books/Standard/7003eng.pdf
ESRL, 2013, The Wind Forecast System Improvement Project: Final Technical Report (2013), U.S. National Ocean and Atmospheric Administration (NOAA) Earth Systems Research Laboratory (ESRL).
Freedman, J.M., Filippelli, M.V.; Bailey, B.H., 2010, “Comparison of Environmental Conditions Between Offshore Sites in Europe and the United States.” AWEA Offshore Wind Power Conference. Atlantic City, NJ. 5–7 October 2010.
Sirnivas, S., Musial, W., Bailey, B., and Filippelli, M., 2014. Technical Report: Assessment of Offshore Wind System Design, Safety, and Operation Standards. January 2014.
Peter Nyegaard Jensen, “Offshore wind: big is beautiful”, The Switch, 28 February 2018, http://theswitch. com/2018/02/28/offshore-wind-big-beautiful/
https://theswitch.com/2018/02/28/offshore-wind-big-beautiful/
World Class Performance by World’s First Floating Wind Farm, February 2018. Retrieved from: https://www.equinor.com/en/news/15feb2018-world-class-performance.html
Richardson, E., February 2018. “The Benefits of Offshore Wind Energy”, Retrieved from: https://www.renewableenergyhub.co.uk/blog/the-benefits-of-offshore-wind-energy/
Bailey H., Brookes L. K., Thompson M. P., 2014., “Assessing environmental impacts of offshore wind farms: lessons learned and recommendations for the future” Retrieved from: https://aquaticbiosystems.biomedcentral.com/articles/10.1186/2046-9063-10-8
International Energy Agency, “Offshore Energy Outlook”, May 2018, retrieved from: https://www.iea.org/weo/offshore/
Figure 1: thumb.php
Figure 2: Offshore Wind Power Capacity by Country
Figure 3: Different-types-of-wind-turbines-1.png
Figure 4: Offshore Wind Foundation Types from windpowerengineering.com
Figure 5: Offshore Wind Energy Market from Global Market Insights