1. The document analyzes the design calculations, cost of electricity, and sensitivity analysis for a proposed 1.9 MW offshore wind turbine. It finds the total annual energy output would be 3,204,093 kWh and the cost of electricity would be 8.4p per kWh. 2. It discusses potential environmental issues from constructing and operating offshore wind turbines, such as disrupting habitats and migration patterns of marine life. However, evidence also suggests turbines may create artificial reefs that increase biodiversity. 3. Social and economic factors could also impact development, as some object to reliability concerns or visual/navigational obstructions, though comprehensive assessments could mitigate negative impacts. The future of the technology

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Energy Resources & Policy Assignment 1: Wind Power
Gordon Best 201109204
Contents
Design Calculations........................................................................................................... 1
Cost of Electricity ............................................................................................................. 3
Sensitivity Analysis ........................................................................................................... 4
Environmental Issues ........................................................................................................ 6
Design Calculations
 Calculate the Total Amount of Energy Captured in a Typical Year of Operation:
– Rated speed= 10+[0.2N], where N=2, =10.4m/s
– Cut In speed =4m/s
– Cut Out Speed= 24m/s
– Interest rate 6%
– 15 year operation
– 3% Maintenance Costs
– Full Area of turbine @ 94m diameter =6939.78m2
– ρ= 1.21
Cp= 0.42, so rated power @10.4m/s= 0.5 x 1.21 x 6939.78 x 10.43= 4.7MW
Theoretical rated power adjusted by Cp= 0.42 makes 1.9MW [RATED POWER]
CI= 0.26 MW x 0.42= 0.1MW
CO=58MW x 0.42= 24MW
 Establish Number of Days for Ci, Co, and R operating speeds:𝑉∞ 𝑇0.5
= 60
T2= RATED =(
60
10.4
)2
= 33.29 days
T1= CUT IN= (
60
4
)2
=225 days
T3= CUT OUT= (
60
24
)2
=6.25 days

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 Total Annual Output = Cp x 0.5 x ρA [ ∫ 𝑉3𝑇1
𝑇2
] + V3 R [T2-T3]
1st Component= 0.42 x 0.5 x 1.21 x 6939.78 [∫10.43 [
1
√𝑇
] 3 dt
=0.42 x 0.5 x 1.21 x 6939.78 x [
−2
√𝑇
]
225
33
(where integral solves to = -0.1333.. – 0.348..= 0.215= 215000)
=0.42 x 0.5 x 1.21 x 6939.78 x215000= 379130591.1
Multiply 379130591.1 by 0.21 days = 79947166.32 WDAYS [COMPONENT 1]
2nd Component= V3 R [T2-T3]
=0.42 x 0.5 x 1.21 x 6939.78 x 10.43 [33-6]
=1983583 x [27]
=53556742.03 WDAYS [COMPONENT 2]
Total Annual Output = Cp x 0.5 x ρA [ ∫ 𝑉3𝑇1
𝑇2
] + V3 R [T2-T3]
=79947166.32 + 53556742.03
=133,503,908.4 WDAYS
=133,503.9084 KWDAYS
Establish in kWh, so multiply by 24
=133,503,908.4 x 24= 3204093802= 3,204,093.9 kWh [TOTAL ANNUAL OUTPUT]
Mean Power Output=
133503
365
= 365.76kW [MEAN POWER OUTPUT]
Capacity Coefficient=
365.76
1900
= 0.19 [CAPACITY COEFFICIENT]

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Cost of Electricity
Annual payment =
Cr (1+r)^n
(1+𝑟) 𝑛−1
where N=15 years
 Capital cost, C, is [2+0.025N] x106
= £2.050 x106
(£2.05million) [CAPITAL COST]
– Interest rate 6%
– 15 year operation
– 3% Maintenance Costs
– (1+r)n
= 2.4
Annual payment =
Cr (1+r)^n
(1+𝑟) 𝑛−1
=
2.05𝑥106 𝑥0.06 2.4
2.4−1
= £211,581 [ANNUAL PAYMENT]
Maintenance @3%= 0.03 x 2.05x106
= £61,500 [ANNUAL MAINTENANCE COST]
Total Cost Per Year= £211,581 + £61,500= £273,081 [TOTAL ANNUAL COST]
Total Cost (15 years) = £4,096,215
Cost of Energy=
Annual Cost of Project
𝐴𝑛𝑛𝑢𝑎𝑙 𝐸𝑛𝑒𝑟𝑔𝑦 𝑃𝑟𝑜𝑑𝑢𝑐𝑡𝑖𝑜𝑛
=
273081
3204093.9
= £0.084= 8.4p per kWh [ENERGY COST]

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Sensitivity Analysis
 Changes in Maintenance Costs
When the maintenance percentage of 3% is increased or decreased, the effect on
the cost of electricity can be observed to have a linear trend of 63% gradient. This
can be indicated by the R2
value of 1, where the linear regression model fits
perfectly. By reducing the maintenance percentage of the project cost to a third of
the current value (1%), the cost of electricity reduces by 17.6% from 8.4p to 7.2p
 Changes in Repayment Period
Alterations in the repayment period are less fitting to the linear regression model, with an
R2
value of 0.7839, and gradient of -0.41. By reducing the payback period to a third of the
standard period (to 5 years), the cost of electricity increases by 2.8 times to 13.3p,
indicating a close value of negative correlation, but not as predictable as alterations in the
maintenance percentage.
y = 0.6398x + 6.6035
R² = 1
5
7
9
11
13
15
0 2 4 6 8 10 12
CostofElectricity(p)
Maintenance as a Percentage of Capital Cost(%)
Cost of Electricity vs Maintenance Percentage
y = -0.4132x + 13.312
R² = 0.7839
0
5
10
15
5 10 15 20 25 30 35
CostofElectricity(p)
Payback Period (Years)
Payback Period vs Cost of Electricity

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 Changes in Interest Rates
The correlation between alterations in the interest rates and cost of electricity is
nearly a perfect fit to the linear regression model, with an R2
value of 0.9831. By
doubling the interest rate from 6% to 12%, the cost of electricity increases by a
factor of 1.73 to 14.8p.
In order to compare the sensitivity of the three variables considered against the cost of
electricity, these have been placed into the same graph. It can be seen that changes in
interest rates lead to the highest levels of change in the cost of electricity.
y = 105.59x + 2.0777
R² = 0.9993
0
5
10
15
20
0.02 0.04 0.06 0.08 0.10 0.12 0.14
CostofElecricity(p)
Interest Rates (Decimal)
Interest Rates vs Cost of Electricity
0
2
4
6
8
10
12
14
16
0 5 10 15 20 25 30
CostofElectricity(p)
Adjusted Variable
Cost of Electricity- Variable Comparison
Maintenance
Period
Interest
Rates
Gradient R^2
Maintenance 0.6398 1
Period -0.41 0.78
Interest Rates 105.6 0.99

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Environmental Issues
Despite the recent surge in interest and investment in offshore wind turbines as a
renewable energy source, there are concerns about the environmental impacts of these
systems. This section of the report will analyse these concerns, look to see how these will
affect the progress of development, and investigate if the potential of these systems is
limited by fears of significant environmental, social and financial impacts.
The environmental issues can be split into two sections; firstly the impact of the system on
the fauna of the area, where habitats are disrupted by the construction and operation of
the turbine, and secondly the impact on the general environment, such as the water and
seabed.
Looking specifically at the turbine's impact on the fauna, there are concerns that the
construction and operation will drastically alter the habitat and migration patterns of
various aquatic lifeforms, for example, damages from noise and vibrations to plankton and
fish living at the seabed during the pile driving and scouring phases of construction. In
addition to the marine life, birds and other flying mammals are known to be impacted by
turbine development, where collisions and pressure changes can fatally injure certain
species. As well as the direct environmental impacts, there are possible indirect
repercussions of development, where the animals depending on the marine ecosystem, for
example whales’ dependency on plankton, could experience problems with disruptions in
the food chain.
Concentrating on the general environment, the turbine development may lead to
hydrodynamic issues, where obstructions in the waves lead to changes in the wave pattern,
resulting in shifting sedimentation, which may affect land based ecosystems.
In addition to alterations in the sedimentation of waves, the general environment may be
affected by issues relating to thermal turbulence, turbidity, and the electromagnetism
associated with turbine operation, although further study is required to analyse the extent
and severity of these factors.
In terms of the probability of these impacts occurring, there is little evidence to suggest
that ecosystems or the general environment is negatively affected by the development of
offshore wind turbines. Some evidence has suggested that turbines may in fact create an
artificial reef, which could accommodate organisms such as crabs, leading to increases in
the biodiversity levels of the area.
In order to develop a better idea of how the wind turbines affect the environmental
systems in the proposed site, Environmental Impact Assessments (EIA) and Strategic
Environmental Assessments (SEA) should be carried out. With specific and comprehensive
evidence, a strategy can be put in place to mitigate any negative impacts, and ensure that
the development is carried out using responsible and sustainable methods.
With responsible and sustainable development at the heart of the project, there are few
environmental limits to the potential of the wind turbine system.

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However, there are social and economic factors to consider. The obvious concern regarding
renewable energy systems is the intermittency of generation, where high or low wind
speeds lead to the turbines being shut down, resulting in no electrical generation. With
these concerns about reliability, there may be objections to such a development being
relied upon, despite recent interest and tax incentives in renewable systems from
governments as a way to provide energy while reducing carbon emissions.
In addition to concerns about the reliability of these systems, there is a possibility that
objections may be made regarding the visual obstruction, or navigational obstruction to
ships and fishing boats in the area, depending on the proximity of the turbine system to the
coastline. To better understand the social context of the development, a Social Impact
Assessment (SIA) should be carried out. This assessment will help the design team to
understand the factors which are important to the public regarding the turbine design and
location. With a comprehensive study completed, a strategy could be developed to mitigate
any negative social impacts, and ensure the development is socially responsible.
To conclude, there are a variety of environmental issues which may affect ecosystems and
the general environment in the construction and operation of offshore wind farms.
However, the severity and likelihood of these impacts occurring is not sufficiently
understood to confidently predict the future of this technology. Several studies suggest the
perceived negative environmental impacts are not as severe as some campaigners suggest,
and some go as far as suggesting the turbines may be a positive contribution to marine
ecosystems. The deciding factors for the degree of future use are likely to be socially and
economically based. Concerns regarding the reliability and general social impact of these
systems are common, but in a world where concerns are also frequent about climate
change and fossil fuel dependency, compromises may be required to ensure that energy
demands are met. The limits to the potential of this technology is dependent on the
priorities of the energy sector in the future. Whether the various carbon emission targets
and climate change studies make any significant changes to the energy industry remains to
be seen. However, if the environment is made a priority, and renewable energy systems are
required to supply the energy demands currently generated by fossil fuel based systems,
then offshore wind turbines should be considered a valuable component of the solution.