The Investment Case for Floating Offshore Wind Turbines
The generation of electricity that is clean and also renewable on a large scale is one of the challenges the human race faces in this 21st century. However, the good news is the fact that technology is playing a very important role towards dealing with this challenge. This is seen in the innovative ways implemented by the human race through science and technology in an attempt to address challenges. The use of wind to generate renewable and clean energy has taken an upward growth trend at a faster rate with the focus on both offshore and onshore wind firms. Its current global installed capacity is over 80 gigawatts (Sclavonous, 2011).
Sclavonous observes that the focus is now shifting to offshore wind energy generation. This is a relatively new way of generating energy from wind in which floating wind turbines are used in the process of power generation. Inspired by the advancement in the oil industry, it has become possible to design the 5MW floating wind turbines ballasted (Sclavonous, 2011). This would enable them to float stably without the support of a mooring system. In turn, this enables the full assembly of the floater and the wind turbine that is equipped with among other things; cranes, manufacturing facility and stores (Sclavonous, 2011). He adds that large wind turbine blades are not difficult to transport using ships to the manufacturing facility situated at the coast. After completely assembling them on the water, the wind turbines are towered to the offshore wind farm site.
Floating Wind Technologies
Sclavonous (2011) identifies three types of wind turbine floaters. They include: the Tension Leg Platform (TLP), Spar Buoy Floating Wind Turbine, and the Hybrid TLP-Spar Bouy Floating Wind Turbine. He explains that the TLP is joined with the floor using steel tethers under high tension as a result of the connection to the turbine floaters. This way the system does not tilt because of the wind and waves effect. According to Sclavonous (2011), the TLP concept only allows the horizontal forward and backward oscillation that is similar to low wave-quake stirred by the gentle waves. He further adds that, at the floor of the sea, the tethers are either joined to a concrete block that has been packed with steel scraps or a sufficiently heavy mineral which can endure the pretension of tether as well as the fluctuation in a heavy storm. The cost of this concrete is a main thing that drives the economics of the concept of TLP.
The second concept of the wind turbine floater illustrated by Sclavonous (2011) is the Spar Buoy. In this type of turbine floater, the connection is done to the seafloor strong catenary mooring lines made using steel. Here, the catenary moored Spar Buoy at times tends to tilt as a result of the wind and wave action. However, the tilting can be reduced significantly by using a catenary configuration which moor lines together with the points of connection as well as those of pretension to the marker/buoy chosen in order to reduce as much as possible the turbine’s response (Sclavonous, 2011). Just like the TLP, Sclavonous (2011) says that Spar Buoy meant for a wind turbine floats while more stable before it is attached to the catenary. This concept is advantageous because the static together with the dynamic strength of catenary anchors can be less compared to the TLP tether strength making its cost to be lower.
The third concept of the hybrid floating wind turbines is a system that brings together both TLP and Spar Buoy concepts (Sclavonous, 2011). In this concept, it becomes important to choose carefully the initial strength of the catenaries, the composition and the angle in relation to the floor of the sea. Another aspect that requires the careful selection according to Sclavonous (2011) is the rim radius at the point that the fairleads and the buoy are connected. Taking a keen note of the measures is important in ensuring both the static and dynamic tensions of catenaries are minimized. This assists greatly in reducing the cost for laying the foundation. Furthermore, the tilting of the dynamic tower is also reduced greatly to meet the threshold set by the manufacturers of the wind turbines. Sclavonous (2011) attests that this concept combines the advantages of TLP and Spar Buoy. One of the things that set the cost for the hybrid wind turbines is the required maximum strength of mooring lines which is important in the uplift capacity of anchors (Sclavonous, 2011).
Transmission of Offshore Wind Power
According to Sclavonous (2011), the electricity transmission from floating offshore wind can be done by first channeling power generated to a centrally placed sub-station through electricity lines laid on the floor of the sea. This is then followed by the transmission of high voltage power using a central line set under the floor of the sea. The economics of offshore wind power generation is mainly determined by the anchor cost, the cost of maintenance and operation and the wind turbine cost among other things. Sclavonous adds that maintenance and operations cost is of great importance to wind farms and should always be kept as low as possible. The hybrid turbine concept has an advantage in that it can be dismantled and moved to the shore for the serious maintenance and a part replacement.
Reasons for Floating Wind Turbine
According to Sclavonous (2011), a main driver to floating offshore wind turbines is the increasing need for electricity and the campaign on the need to focus on a cleaner and renewable source of energy. With the current debate on global warming, there has been a widespread call for the replacement of non-renewable sources of the power like oil, coal, and gas. Among some cleaner sources of energy, which are recommended in this debate, there is wind energy, with offshore wind power currently gaining much support over the onshore sourced power. This is evident in the way the energy source is embraced even in the developed nations. For instance, in the U.K., the Carbon Trust has a belief that the mass deployment of offshore wind is very important in bridging the energy requirement gap. This increasing need for a cleaner source of energy also saw Japan utilizing its advanced energy technology to put up the Fukushima offshore wind farm. Watanabe (2013) notes that this was an ambitious development aimed at harnessing wind power.
One very important feature of offshore wind turbines is that they do not require the physical foundations like the onshore wind power. This is because they have floating platforms which are normally attached to the seabed by mooring lines. Thus, this implies that they can be effectively launched in the much deeper water. Consequently, this is the good news for countries with deepwater coastlines like Norway, Portugal, and Japan (Warren, 2011).
According to Warren (2011), using floating wind platforms is advantageous because it also allows developers to access waters where there is the stronger but less turbulent wind, which, in turn, helps reduce the overall cost of wind energy. Additionally, floating platforms can be assembled at the quayside without the need for dynamic positioning vessels. This is important since it reduces further the cost and risk of deployment activities.
Warren (2011) further argues that with the wind float’s base it is possible for the water level to be adjusted in three columns to keep a turbine level. Currently, the engineers have been able to design a tower which is tall and also slender so that its center of gravity lies below the structure’s center of buoyancy. This is what is allowing it to remain steady even when the seas are turbulent (Warren, 2011). He adds that the wind float also saves steel since its tower is normally placed on a column instead of a platform. This greatly economizes and gains a structural support with steel cables.
Current State of Investment in Wind Energy
According to Hill (2012), wind energy is advocated for as clean energy because it does not require fuel or water to operate; neither does it pollute the air or water. It also does not experience the price fluctuations that fossil fuels experience. Currently, a lot of research is being done toward improving the turbine technology with a more focus on floating offshore wind turbines. Most countries with the large water bodies like Japan are now investing a lot of their resources and technology in offshore wind turbines. This is a really promising future for this technology and power generation concept. However, it looks like it is not possible to have wind power without problems. Wind experiences internal problems of the unstable supply because the intermittent generation of energy from a month to a month with seasonal changes makes it difficult to stabilize the electricity output. Another issue, more so in the U.S., is the best location for wind farms. Most of these farms in the U.S. have their locations located right in the middle of the country, where they experience a lot of opposition as a result of noise and health concerns. Even though the floating offshore wind turbine is more costly to develop than the onshore one, the potential for a large amount of a steady generation cannot be overstated.
Hill (2012) has identified a number of companies involved in the floating of offshore wind turbines especially in the U.S. One is the ABB limited which is a Swiss company whose products and services include the power transmission and distribution as well as plant automation. Another company majorly involved in it is the Parker-Hannifin (PH) which is a large diversified industrial manufacturing company that has a wide array of products. Warren (2011) observes that the commercialization of floating wind turbines is actually showing a faster growth than was previously anticipated in the past few years. This can be attributed to the fact that it has become much easier to understand the problems, drawbacks and some of the hidden costs associated with installing fixed structures.
Why A Shift from Coal, Oil and Natural Gas to Offshore Wind Power
With the current debate on global warming, nations have continued to receive pressure to embrace technologies which are environmentally friendly. The top on this debate has been a need to shift from using the non-renewable source of energy to renewable and environmentally friendly ones. According to Chey (2013), it is based on this that the focus is currently more on renewable energy sources like wind energy and not on coal, oil or natural gas. He has identified a number of disadvantages associated with these non-renewable sources of energy. To start with, he has pointed out that burning coal leads to emission of harmful gases like sulfur dioxide, nitrogen oxides, carbon dioxide, sulfuric acids and arsenic.
Burning coal also leads to the emission of twice as much carbon dioxide to produce the same heat as the same amount of natural gas. The burning of coal by large-scale factories to power industries has led to acid rains in some regions. Coal mining also scars the landscape. Moreover, the equipments used for mining are large and noisy which negatively affect the wildlife and even the human beings working with them. Transporting coal can as well be problematic since it requires an extensive transportation system. It can at the same time cause even more pollution resulting from emission by transporting tracks. Additionally, coal is non renewable and very limited stocks are remaining. This means that with time, they will be entirely depleted. The mining industry can also cause health problems for a worker or worse, even death based on the kind of work which by all standards is potentially dangerous (Chei, 2013).
On the part of oil, Chey (2013) notes that even though oil has many advantages, it has also as many disadvantages. Firstly, oil is a non-renewable energy source that takes millions of years to form; and, therefore, once the existing and any new reserves are depleted, it will take long for nature to replenish it. While oil is relatively easy to transport, one of the most common transportation methods, shipping using supertankers, at time, results into spills into the waters, thus, affecting the marine life. Burning oil also generates carbon dioxide which is a greenhouse gas. Additionally, oil contains sulphur which when burnt forms sulphur dioxide. When sulfur dioxide combines with the atmospheric moisture, it forms sulfuric acid which eventually comes down as acidic rains. This has the potential of destroying forests as well as eroding rocks and masonry structures, both natural and man-made. Finding additional oil reserves has also become an extremely costly process with no guarantee of success. Even though many of the products extracted from oil are of huge befits to mankind, many of them are also highly toxic.
Chey (2013) indicates that natural gas, just like any other fossil fuels, contributes to greenhouse emissions. In case the large scale use of gas continues, it is projected that gas from landfills would not be able to meet the world’s demand. The world will would, therefore, be relying on the non-renewable forms of gas which is also a contributor to the green house gases and, thus, global warming. Chey (2013) further notes that natural gas is highly volatile and can be dangerous if handled or transported carelessly.
As a result of the drawbacks of these fossil fuels, it is expected that the more focus of technology on wind generated energy is going to bring a new dawn. Carbon trading and offset programs are potentially going to boost the development in floating offshore wind turbines. According to Gustafson (2010), the program for reducing carbon dioxide emission is a very important development for the renewable energy industry. It is because carbon credits created from the use of bio-fuels and wind energy helps in meeting the established goals of many countries. He says that carbon credits generated from renewable energy are very valuable. Gustafson (2010) defines the carbon offset as a credit for the reduction of greenhouse gas which is achieved by one party and can be bought and used to compensate the emission of another party. The offset is measured in terms of the carbon dioxide equivalent. It is in most cases bought and sold through international brokers and online trading platforms. Gustafson notes that companies investing in wind energy do benefit because of the carbon offset they sell. This has, in turn, made wind energy related projects more economically viable compared to those associated with non-renewable energy. The buyers of the offset benefit because they can claim their purchase has been as a result of non-polluting and environmentally friendly energy which they are able use in mitigating greenhouse gas emissions.
The severe impacts of a climate change may be reduced if measures are put in place to transform current energy systems. According to the IPCC Report (2012), renewable energy sources have a large potential of causing a substantial reduction of the rate in which the greenhouse gases are emitted from the fossil fuels’ combustion. Thus, it should be perceived as a viable and cheaper way of mitigating the adverse change in the climate. If a proper implementation is done, renewable sources of energy like the offshore wind energy can help countries realize both the economic and social development, improve energy access, as well as promote a secure and sustainable energy supply. The source can also lead to the reduction of negative impacts associated with energy provision.
The report on renewable energy sources and the climate change mitigation impartially assesses the scientific role played by renewable energy towards mitigating global warming. Its report focuses on six renewable sources of energy namely; direct solar energy, bioenergy, geothermal energy, ocean energy, hydropower, as well as the wind energy. Additionally, it also considers its consequences on both the environment as well as the social lives of people due to technologies that are used in the process. It presents strategies to overcome the technical as well as non-technical obstacles in their application (IPCC, 2012).
Based on the report, it becomes evident that green energy is a priority of many nations, both developed and developing. For instance, in the U.S., the Obama administration has embarked on developing a cap-and-trade program focused on reducing carbon dioxide emissions. Pengg (2012) has observed that when Barrack Obama contested for presidency in the year 2008, among the changes that formed the part of his agenda was a new energy plan for the people of America. His plan included the requirement to significantly increase renewable sources of energy. Today, the U.S. does enjoy the use of a significant amount of energy being generated from renewable sources. It has since been revealed that wind power was the renewable energy the President was referring to as would be a key to the American energy in the future (Hill, 2012). The report also evidences how countries such as Japan set aside billions of money for wind power generation technologies. With large water bodies surrounding Japan, floating wind turbines are seen to hold the promise of opening up large areas for the production clean energy.
Reasons for Storing Energy
A volt gas volt storage concept uses surplus electricity generated by renewable and nuclear sources to produce hydrogen through electrolysis. While explaining the concept, Dr. Pengg (2012) notes that it involves a process in which hydrogen is combined with CO2 to produce methane. The resulting methane is then channeled and stored in the existing natural gas grid and eventually used just like is the case with natural gas. This gas is used in generating power as well as in transportation and other thermal and industrial uses. He says that stored methane generated in the process can become the battery for renewable energy, simultaneously making hydraulic fracturing obsolete Sclavonous (2011). He further points out that in France, where electricity generated is higher than the demand, the potential production could be used in the Volt Gas Volt plants. This would eventually help reduce a payback period for the amount invested on VGV Sclavonous (2011). Conversely, this would translate into a higher growth in the Volt Gas Volt storage concept, hence, a promising future.
Case Study: The Role of Fukushima Event
This was a project funded by the Chinese government. It aimed at halving costs related to the setting up of floating turbines to allow the commercialization of technology. Its piloted project had only a substation which was connected to turbine with a capacity of 2 megawatts. The project’s preceding face saw Mitsubishi Industries installing additional two turbines whose total capacity was seven megawatts (Bossler, 2013).
The project majorly aimed to help enhance China’s energy source following the 2011 nuclear disaster as well as the decline in atomic power productions. The Japan’s investment in offshore wind power has not been recognized globally. The country experienced a faster growth in its know-how in as far as the floating technology is concerned. Today, the technology is among the key contributors to the country’s strategic edge, especially in as far as the penetration of its overseas’ markets is concerned. Though Fukushima was necessitated by an anticipated incident, it has helped to change the energy mix of the country for better. With the current concern for global warming, other countries with favorable sea beds should consider investing in offshore wind power (Bossler, 2013).
The innovative technology of floating offshore wind turbines is new. It has a very high potential of producing a clean, renewable and environmentally friendly source of energy. It is, therefore, imperative that the floating offshore wind firms and energy generation using this technology is given the serious attention. With many countries embracing the clean energy generation and the world focus on the reduction on greenhouse gas emissions, it has expected that more funds are going to be injected in both floating offshore and onshore wind turbines for energy generation.