De Montfort University: Offshore Wind Power Technology in USA Analysis

This report examines the state of offshore wind power technology in the United States. It begins with an executive summary and table of contents, followed by an introduction to wind power and its history. The report then delves into the current state of offshore wind power production in the USA, analyzing its impact on the energy system and other fuels, technical developments, and barriers to implementation. The analysis includes data on wind speeds, turbine technology, and the environmental impact of offshore wind farms. The report also explores the economic aspects, including long-term cost predictions and government incentives. The conclusion provides a personal reflection on the feasibility and widespread adoption of offshore wind technology in the USA, considering its potential to diversify the energy supply and create new markets. References are included for further research. This report is a comprehensive overview of the topic, providing valuable insights into the challenges and opportunities associated with offshore wind power in the United States.

De Montfort University
Investigation on Offshore Wind Power Technology in U.S.A
[Type Name here]
[Type course module here]
[Type module name here]
May 2018
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Executive Summary
From a worldwide point of view there are great advancements in the exploration of the wind
power technology, with major investments in most European countries. The United States, in
particular does so well in this energy sector. This has been mainly caused by the vast resources
of the onshore wind power readily available to satisfy to a great degree the power needed in the
country. However, on land wind power is smaller compared to the offshore due to the increased
wind speeds in the seas. This paper presents a critical assessment of the coastal resources in the
United States by exploring the possible use of this promising deep-water wind technology,
predicting the long term cost of energy trends, the resulting impacts of its use to the environment.
The possible hindrances to the full development of the technology in the United States of
America is analysed and then a personal reflection on the impacts of the widespread adoption
and the feasibility of using the offshore wind technology is given to conclude the report. The use
of offshore wind technology can be used to greatly diversify the electric energy supply of the
United States and provide a new market for wind energy to complement on the onshore
developments.
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Table of Contents
Executive Summary.........................................................................................................................2
Table of Contents.............................................................................................................................3
Introduction......................................................................................................................................4
State of offshore wind power production in the United States........................................................7
Impact on the energy system and other fuels.................................................................................10
Technical developments................................................................................................................12
Barriers to offshore wind power....................................................................................................14
Personal reflection.........................................................................................................................16
References......................................................................................................................................17
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Introduction
In the category of clean energy, the wind power makes one of the most actively sort for energy
resources and is developed on many countries around the world. The resource forms one of the
oldest source of clean and renewable energy. In the early centuries the wind power was used in
boat propulsion along River Nile, water pumping to large farms in China, and for draining lakes
and marshy lands in Germany (Wind Energy Foundation, 2016). The increasing shortage and
depletion of the fossil fuels (oil) around the world change the worldwide view of the energy
picture, thus inspiring interests in alternative sources of energy: this therefore paved up way for
the re-entry of wind turbine technology mainly for power generation. Environmental and
scientific studies in Europe resurfaced the immediate concern on the adverse effects in continued
use of the fossil fuels to the environment, which indicated that the global climate would change
if no alternative sources of clean energy were developed; therefore wind technology dramatically
picked up, both in research and development in Europe. Today, wind power technology exists
from small sized turbines for charging batteries to large onshore and offshore gigawatt sizes for
electric supply to the national grids (Wind Energy Foundation, 2016).
Electricity is generated through the conversion of the wind’s kinetic energy (contained in air
currents) into the rotation of wind turbines, as they flow past the turbine blades, which thus
rotates a motor inside a generator to produce power. This power is then conveyed through cables
down to the base of the tower which then combines with power from other windmills then
collected at a local electricity distribution network (Marc , et al., 2010). The windmills are
usually spread out in a common area (in a wind farm) for energy collection and also to reduce the
adverse environmental impacts. Each windmill has a control computer system installed within to
monitor the wind speeds then auto sets the blades to rotate at a safe speed. In cases of
exceedingly high wind speeds, the computer control system ensures a complete automatic
turbine shut down thus preventing the turbine from turning; this prevents cases of accidents
(Genesis Energy, 2010).
The main components of any offshore wind system include a meteorological system: this mast is
used to evaluate the meteorological environment of the project area and other necessary site
resource data like the temperature of the surrounding air, the barometric pressure temperature of
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the sea water, and velocity magnitudes and profiles of the ocean current. These data are collected
at multiple heights of the meteorological mast using anemometers and are an ideal indicator of
the estimations of the operation management and the wind turbine performance. Second to this is
the support system including the foundation (used for turbine support), transition piece (this
simplifies the tower attachment) scour protection (prevent degradation of the entire support
system from the adverse environmental conditions). The foundation design is affected by the
speed of wind, height of the wave currents, depth of water and the size and the weight of the
turbine. Common examples of foundations are the use of monopoles, jackets and tripod stands
(having a central stand with three other steel tubes). Floating structures have become a recent
development in the offshore industry in cases of deeper waters (deeper than 100 meters). These
consists of uniform anchoring strands connected to a floating platform as developed by the
Statoil Hydro (the Hywind in Norway by 2009) and the Blue H in Massachusetts.
Onshore wind technology has been on the lead in generating renewable energy in the United
States with a 7TWh in 2010, an amount able to save 6 million tonnes of carbon dioxide which
would have otherwise been released to the atmosphere. It is expected to generate about 30TWh
by 2020 (American Geosciences Institute, 2011). It is true that the power sector is the whole
problem to the global emission of greenhouse gases, but on the other hand it is the largest single
contributor to these emissions – a share of about 40 percent of energy comes from carbon
dioxide emission related sources. The dramatic progress of the developments in the wind and
solar technologies in the past decades have pointed the world to the point for which the vision of
having a clean sustainable energy in the near future, for the worldwide economy is well within
reach, and has therefore become the explicit policy direction of many an increasing number of
countries (Greenpeace International, 2014).
In contrast to the onshore technology, offshore wind power production involves constructing
wind farms within large water bodies like the oceans or seas for wind energy harvesting used for
electricity generation. There is available higher speeds of wind in the offshore compared to the
wind speeds on land, thus there is a higher per unit installation so offshore wind power’s
electricity generation is higher amount of power generated per unit capacity of wind turbines
installed offshore than onshore.
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Figure 1: Offshore windmills (fixed-built and floating type) in Baltic Sea, Denmark (Daniel,
2013)
According to (Jonkman, et al., 2009), by 2017 18814 MW was the total worldwide offshore wind
power capacity installed, with Northern European countries like the United States, Germany,
Netherlands and Taiwan having the largest share of the total production. The Hornsea Wind
Farm in the United States which is currently under construction will become the largest wind
energy production farm when completed, giving a power capacity of about 1,200 MW
(American Geosciences Institute, 2011). Taiwan’s greater Changhua’s offshore wind power
station expects a capacity of 2400 MW installed. The general cost of constructing offshore wind
power has always been historically higher than that required for onshore wind power generation,
although this is currently on a decreasing trend in the recent years.
With the increased awareness on the effects of carbon emission to the environment, many states
have invested in wind technology thus lowering the general cost required to set up a fully
functional station. Many governments have provided incentives in this investments by giving
fund incentives, technical trainings and organizing international fora for sustainable wind energy
production (Wind Energy Foundation, 2016). Offshore windmills collects more energy as
compared to onshore mills since the open water bodies allow for longer and larger mills to be
constructed and also higher wind speeds in the seas (Daniel, 2013). Since the offshore
technology utilizes the seas, large tracts of lands, which would otherwise been used (as in
onshore type) are left for economic activities and there is also no blockage of wind flow to the
mill by obstacles like buildings, that is prevalent in on-land wind technology.
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State of offshore wind power production in the United States
Offshore wind turbines are commonly used by a number of countries chiefly, to harness the
kinetic energy of strong and consistent winds that are found over the oceans. Roughly 50% of the
total national population of the United States lives in coastal areas including counties directly on
the shoreline or counties that drain to coastal watersheds. There are high costs and demand of
energy thus often leading into a continued scramble on the limited on-land sources of energy,
between the country’s rapidly growing industries and the bulging population (Office of Energy,
2009). Land-based renewable energy resources like onshore wind power production, geothermal
power and hydroelectric power production stations, are often limited to the cities and thus cutting
off the coastal areas (Right , 1996). Therefore, the abundant offshore wind power that is usually
efficient and clean, can potentially supply immense quantities of clean and renewable energy to
the major populations in the United States coastal cities like New York, Los Angeles and Boston
thus improving life and reducing the overbearing burden on the limited on land energy sources
(Greenpeace International, 2014).
For many years the United States has not fully ventured into the rich wind resource in the
American coastal areas. By 2009 only an additional capacity of 10,000 megawatts of renewable
onshore wind energy was included into the American power line, a figure which led to a 40
percent increase into the total generation capacity. A national mandate is therefore required to
generate this renewable energy for the many coastal states which prove to be potential sources of
renewable power sources. The Unites States government mandated the Bureau of Ocean Energy
Management Regulation and Enforcement (BOEMRE) in 2009 to create regulatory systems on
renewable energy investment agreements which showed a good improvement index of
construction of many several wind farms. The bureau also regulates the development of the
offshore wind energy in both the federal and states’ waters.
It is a common occurrence that there is a higher and uniform flow of wind speeds in the seas and
oceans than on land, thereby increasing the speeds of wind by just only some few miles per hour
will thus immensely produce a significant lager amount of wind electricity (Torrey, 1976). This
can be illustrated by considering a windmill in which the turbine at the site for which wind
speeds of an average 16 mph act upon, would produce a 50 percent more electricity than a
similar wind mill at a site whose blades are acted upon by winds of average 14 mph speeds. With
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this scenario and other innumerable benefits, many investors in the wind technology would
therefore rather choose offshore wind power production to the onshore/on land wind power
option ( Musial , et al., 2013). The United States’ department of energy through the National
Renewable Energy Laboratory (NREL) provides the average wind speed data that has
necessitated research and exploration of the offshore wind technology. With this technical data,
the investors are able to determine the most efficient position and area to set up an offshore wind
farm considering the wind speed and the depth of the shore.
As seen from the figure, wind speeds within the coast of Southern Atlantic and in the Gulf of
Mexico are lower than the wind speeds off the Pacific Coast. On the other hand, the shallower
waters in the Atlantic sea makes the current development of offshore wind farms more attractive
and economical, owing to the fact that deep waters require large sums for investment. Hawaii has
the highest estimated offshore power production potential, roughly accounting to 17% of the
entire estimated United States’ offshore wind resource. The country aims at deploying a target to
achieve a 20 percent the electric power entirely from wind energy resources. By May 2008, the
Department of Energy gave an estimate that the 20 percent target can enable the country’s total
offshore wind power to be 54 GW of installed electric capacity to the national grid. The
department’s main ambition is to foster for energy independence, be an environmental steward
and also to strengthen the economy of the states by availing cheaper clean renewable energy
sources (U.S. Department of Energy, 2006).
The United States’ department of energy in close association with the NREL has furthered out
research works aiming at providing means of assessing the nation’s full potential in the
indigenous resources on wind energy. The research has thus availed a national database of
validated data that defining the significant and specific characteristics used to quantify the
distribution and availability criteria of the essential resources. Of key importance are the annual
average speed of the wind, depth of water within the shores, the distance from the shores to the
minimum turbine locations and finally the state administrative areas. Musial and Butterfield,
(2004) showed that accurate estimation of the full ability of the offshore wind power in the
United States required that regions of potential wind power that are about 5 nautical miles off the
shore be included in the overall estimation than just total exclusion.
The following factors are currently used by the energy department to estimate the states’ wind
potential:
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a) Average wind speed above the surface
A yearly estimate of the average speeds of wind are an indication of the close relation to the
possibly available energy within a particular location and are clearly distincted in category
within the database by their approximate value at a height of 90 meters above the surface of the
water body. These estimates are effectively done through advanced computer numerical models
which are collected from ocean buoys, automated stations of the marine, lighthouses and the
guard stations of the coast (Genesis Energy, 2010). Microwave imaging from the satellite
showed a 10 meter wind speed over the ocean. In a general sense effective power harnessing
from the wind can be effectively dove at a height of about 50 meters above the surface of the
water.
b) Bathymetry
This technology is used in the measurement of the depth of water in oceans, lakes of seas. In
offshore wind technology, the depth of water greatly influences the technology specified for use
to fully develop the offshore wind resource. The existing offshore wind turbine technology puts
to use the monopoles or single-pole mechanism and gravity foundations within shallow water
regions i.e. with depths of up to 30 m from the sea bed (Mackay, 2008). Transition depths of
about 30 meters to 60 meters require the use of tripods, which are truss-like towers and jackets
while regions with deep waters having waters with depths higher than 60 meters uses floating
structures rather than the fixed bottom foundations (although not widely used in U.S.). From the
figure below, the eastern coast and the regions bordering the Gulf of Mexico have a notably
extensive areas endowed with shallow water relative to the shore line and thus provide a good
potential for offshore wind farms. On the West coast, there is a continued rapid dissension of the
continental shelf into the category of the deep waters. There is also a notable increase in the
water depth specifically away from shores surrounding Hawaii. In the regions bordering the
Great Lakes, portions of Lake Ontario and lake Erie there is a characteristic shallow waters while
the other remaining lakes are categorized as primarily deep water lakes. There is a narrow band
consisting of the shallow and transitional water near to the shore (American Geosciences
Institute, 2011). The above data thus gives a clear shows that most of the coastal regions of the
United States’ cities are potential areas useful for offshore wind power harvesting.
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c) Distance from shore
This factor is used to determine the wind power production project’s visibility from the shore i.e.
the initial cost required for the development of a station by having a thorough consideration such
as the length of underwater cable needed to connect the offshore wind project to land-based
electricity distribution facilities (Marc , et al., 2010). The main goal of this consideration is to
ensure there is a maximum energy production with minimal operating costs and capital costs.
Most of the shores in the United States being shallow have shown that the distance from the
shore is minimal (this results in lower electricity transmission losses) as compared to other
countries thus minimizing the connection costs.
Impact on the energy system and other fuels
The offshore wind energy is a great source of clean and renewable energy. From the literature
it is realized that the resource if correctly harvested can lower the carbon emission to the
environment by almost 40% of the total annual carbon emissions. According to MacKay,
(2008) the offshore wind farm is highly promoted by the U.K. government due to high
productivity resulting from high and steady winds in the seas. This offshore method also
saves on the limited physical space that could be taken by the onshore windmills (Mackay,
2008). The department of energy in the United States showed in their annual report that
offshore wind energy does not contaminate the environment, since it involves no combustion
of carbon emission products and the source is also inexhaustible.
Wind currents are always available and is naturally occurring hence there is no fear of the
source being exhausted. The wind power is a chief source of clean power in regions of high
wind speeds like Netherlands (United States Energy Department, 2015). Through the
continued use of wind power, the demand for fossil fuels decreases greatly from the
population and the industries thus limiting its use to only internal combustion engines
requiring fossil fuels. This technology thus helps to prevent adverse climatic change in
Europe. It is a leading technology at avoiding CO2 emissions thus
contributing to the continued commitment of the U.K. to cut out the
poisonous gas emissions causing global warming and greenhouse gases. A
report by the University of Birmingham on the economies of Offshore Wind
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states that for every kilowatt-hour of wind power produced there results a
reduced environmental pollution by a factor of twenty one as compared to
the impact produced by oil; it is ten times less than the impact caused by
nuclear energy that of nuclear energy and five times less than the gas
energy effects (Wind Energy Foundation, 2016).
The clean wind energy can thus be diverted into running the main industries in the States and
powering the nation’s population living within the coastal cities. The power scramble between
domestic supply and industrial supplies is thus cut by 60% of the initial demand, the on land
energy sources like the geothermal and hydroelectric power sources are thus relieved of the
exploitation. These surplus energy can then be channeled to the more demanding industrial
sector to run the factories (Nina, 2014). The result is improved index on employment among
the citizens, low production cost, highly improved living standards and thus reduced social
related problems in the country. It is estimated that wind energy costs every average home a
total of 1.3 Euros per month and also saves 160,000 euros for every United States industrial
consumer on average annual rate. This makes the economy to greatly grow and open up wider
international markets for the nation.
The available offshore wind energy has also improved the science and research works in the
U.K. Most energy based researches have been funded by the surplus income generated as a
result of the cut in the country’s power demand. The energy department has furthered out
expensive exploration on better and new alternatives to cheap clean renewable sources of
fuel. Notable is the increased research in the nuclear technology, The Nuclear Energy Institute
in the United States has undertaken high levels of research into the most economical ways of
generating power through nuclear technology and how to dispose the industrial refuse in a
more environmentally friendly manner. This has thus supplied the country with nearly 20% of
clean reliable and essential source of power, thus reducing the carbon emission to the
atmosphere.
There has also been a high investment in the clean solar power technology.
The plant includes utility-scale and local distribution scales, producing over 50GW of solar
power installed capacity (Alex, et al., 2010). This accounts for 1.37% of the total electricity in
the United States. Most onshore wind farms negatively affect the human population due to the
high noise levels associated with the rotating turbine blades and the generator noises. This
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makes them undesirable when located within the human habitat, the offshore technology
therefore fills this niche since they are always located afar off human habitation. Most
European governments have set up regulations covering the permitted noise levels produced
from the windmills through the Acoustics legislation (USEIA, 2016).
Technical developments
In the past decade, offshore wind power technology has witnessed remarkable increase in Europe
and other countries like the USA. The Inter-governmental Panel on Climate Change presents a
report showing that about 80 percent of the energy supplied would by 2050 come entirely from
renewable sources. The increased improvement on the offshore wind technology has been
witnessed besides higher station building costs and power transmission costs, these technological
improvements have been witnessed in the United States of America, Europe and some countries
in Africa (Wind Energy Foundation, 2016).
According to Wind Energy Technologies Office (WETO), continued research inputs have
enabled an increase in the average power plant productivity, i.e. power factor, from as low as 22
percent considering all the installed wind turbines as from 1998 to 35 percent average as at
present and also an increase from the 2000 share of 30 percent ( Musial , et al., 2013). This has
consequentially reduced the average costs of wind energy from the 1980’s fifty five cents per
kilowatt-hour (kWh) to an average of below 3 cents per kilowatt-hour (kWh) in the United States
as at present. For a sure continued industrial growth in the future there must be a continued
evolution in the offshore wind industry by always endearing to build on the previous successes
and limiting the inefficiencies thus improving the reliability of the technology, venturing into
newer potential areas with increased capacity factors and reduced costs. These include:
a) Surface modifications to reduce flow resistance
There are many examples of surface modifications that reduce resistance to flow and
improve performance. The modification on the surface ensures that there are minimal
viscosity drags on the turbine blades which would otherwise lower the rotation efficiency
of the windmill hence increased wear of the turbine bearings and a lower energy
extraction from the wind. The recent invention by Sandia Labs, in which a fluid analysis
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