The document discusses innovations in wind energy harvesting to overcome capacity limits and improve performance of wind turbines and farms. It highlights the need for cost reduction in the wind energy industry, critiques the reliance on subsidies, and explores the potential of larger and taller turbines for efficiency gains. Additionally, it mentions alternative approaches like kite-lofted wind turbines to capture stronger winds at higher elevations.

1. WINDNOVATION™
TAKE WIND POWER TO A HIGHER LEVEL
A PAPER PRESENTING
WIND ENERGY HARVESTING INNOVATIONS
Lawrence L Stewart
September 1, 2016
April 23, 2019 Revised
© Copyright 2019 Lawrence L Stewart All Rights Reserved

2. WINDNOVATION™
TAKE WIND POWER TO A HIGHER LEVEL
© Copyright 2019 Lawrence L Stewart All Rights Reserved Page 2 of 25
INTRODUCTION
WIND POWER IS A PROVEN SOURCE FOR RENEWABLE ENERGY.
WIND TURBINE CAPACITY APPEARS TO HAVE REACHED A LIMIT.
THIS PAPER PRESENTS INNOVATIONS TO ELIMINATE THAT LIMIT.
The paper comprises three sections:
1. A general discussion of the state of the industry is presented based on a
survey of published literature from academia and wind turbine manufacturers.
2. The practices of the aircraft industry are reviewed to determine applicability to
wind turbine design.
3. Innovations are described that significantly improve wind turbine and wind
farm performance.
An Addendum provides information as to how to obtain a copy of the provisional
patent filed with the USPTO that cover he innovations described herein, provided
upon request and execution of Non Disclosure Agreement.

3. TAKE
© Copyright 2019 Lawrence L Stewart All Rights Reserved
INTRODUCTION
Alternatives are presented to the design of
electrical power from wind energy.
Value of the Market
Wind Generated Versus Carbon Based Power Generation
Governments and Wind Industry alike promote Wind Energy as one answer to the worlds energy needs.
However, some sources question that claim a
Critics have provided documentation that wind energy is not competitive with
power generation stations. If their arguments are valid, t
drive down its reported cost premium over conventional carbon based electric power generation. In a
2015 Newsweek article, Professor Randy Simmons
“As consumers, we pay for electricity twice: once t
time through taxes that finance massive subsidies for inefficient wind and other energy producers.
Most cost estimates for wind power disregard the heavy burden of these subsidies on US taxpayers.
But if Americans realized the full cost of generating energy from wind power, they would be less
willing to foot the bill – because it’s more than most people think.”
Professor Simmons claim that the wind industry replies on the PTC (Production Tax Credit) was val
by several articles after the passage of the PTC legislation in 2015. The statement, “
tax credits for investing in wind and solar power, leading experts to predict more rapid growth
have read negatively if the PTC had
Professor Simmons' concern about the true cost of wind
Danish government's decision to abandon new construction of wind farms,
“Denmark’s government abandoned plan
the electricity produced there would become too expensive for Danish consumers.”
“Danes have paid billions in taxes and fees to support wind turbines, which has caused electricity
prices to skyrocket even as the price of actual electricity has decreased. Now,
66 percent of Danish electricity bills
Fig. 1
WINDNOVATION™
E WIND POWER TO A HIGHER LEVEL
Lawrence L Stewart All Rights Reserved
Alternatives are presented to the design of the equipment and systems applied to the generation of
electrical power from wind energy. Energy capture can be increased while costs are reduced.
As reported in the “Global
Wind Report Annual Market
Update 2015
wind generation capacity is
fore-cast to grow by 295
GW over the next 4 years.
At a conservative installed
cost of $1M per MW, the
value of this market is
$295B. Applying the
average installed cost
reported by EIA
for 2013, gives a market
value of $559B
amount substantial
Wind Generated Versus Carbon Based Power Generation
Governments and Wind Industry alike promote Wind Energy as one answer to the worlds energy needs.
However, some sources question that claim as a cost-effective approach.
Critics have provided documentation that wind energy is not competitive with conventional carbon
power generation stations. If their arguments are valid, the Wind Energy industry needs innovation to
drive down its reported cost premium over conventional carbon based electric power generation. In a
2015 Newsweek article, Professor Randy Simmons stated
(3)
:
“As consumers, we pay for electricity twice: once through our monthly electricity bill and a second
time through taxes that finance massive subsidies for inefficient wind and other energy producers.
Most cost estimates for wind power disregard the heavy burden of these subsidies on US taxpayers.
ericans realized the full cost of generating energy from wind power, they would be less
because it’s more than most people think.”
Professor Simmons claim that the wind industry replies on the PTC (Production Tax Credit) was val
by several articles after the passage of the PTC legislation in 2015. The statement, “Congress renewed
tax credits for investing in wind and solar power, leading experts to predict more rapid growth
have read negatively if the PTC had not been extended.
ern about the true cost of wind-generated power was again confirmed by
to abandon new construction of wind farms, as reported in
“Denmark’s government abandoned plans to build five offshore wind power farms Friday amid fears
the electricity produced there would become too expensive for Danish consumers.”
billions in taxes and fees to support wind turbines, which has caused electricity
prices to skyrocket even as the price of actual electricity has decreased. Now, green taxes make up
66 percent of Danish electricity bills. Only 15 percent of electricity bills went to energy generation.”
Page 3 of 25
the equipment and systems applied to the generation of
Energy capture can be increased while costs are reduced.
As reported in the “Global
Wind Report Annual Market
Update 2015"
(1)
, Figure 1,
wind generation capacity is
cast to grow by 295
GW over the next 4 years.
At a conservative installed
cost of $1M per MW, the
value of this market is
$295B. Applying the
average installed cost
reported by EIA
(2)
of $1,895
gives a market
value of $559B, either
substantial.
Governments and Wind Industry alike promote Wind Energy as one answer to the worlds energy needs.
conventional carbon-based
he Wind Energy industry needs innovation to
drive down its reported cost premium over conventional carbon based electric power generation. In a
hrough our monthly electricity bill and a second
time through taxes that finance massive subsidies for inefficient wind and other energy producers.
Most cost estimates for wind power disregard the heavy burden of these subsidies on US taxpayers.
ericans realized the full cost of generating energy from wind power, they would be less
Professor Simmons claim that the wind industry replies on the PTC (Production Tax Credit) was validated
Congress renewed
tax credits for investing in wind and solar power, leading experts to predict more rapid growth
”(4)
, would
was again confirmed by the
ted in May 2016
(5)
:
s to build five offshore wind power farms Friday amid fears
billions in taxes and fees to support wind turbines, which has caused electricity
green taxes make up
. Only 15 percent of electricity bills went to energy generation.”

4. TAKE
© Copyright 2019 Lawrence L Stewart All Rights Reserved
Wind Energy Industry Recognizes Need to Reduce Costs:
Within the wind industry, there is a call for
Marketing and Branding, stated
(6)
,
"With five year PTC extension stability and recent state RPS increases in place, wind manufacturers,
developers, and service providers now have the opportunity
strategy, asking the question: how much further does the cost of wind need to fall to remain
competitive in the future market?
Bigger Is Better
To reduce wind turbine installation costs, one approach is to build
“The turbine size and the type of wind power system are usually related. Today’s utility
turbine generally has three blades, sweeps a diameter of about 80 to 100
0.5 MW to 3 MW and is part of a wind farm of between 15 and as many as 150 turbines that are
connected to the grid.”
“The maximum energy than
can be harnessed by a wind
turbine is roughly proportional
to the swept area of the rotor.
Blade design and technology
developments are one of the
keys to increasing wind
turbine capacity and output.
By doubling the rotor
diameter, the swept area and
therefore power output is
increased by a factor of four.
Table 2.1 presents an
example for Denmark of the
impact of different design
choices for turbine sizes, rotor
diameters and hub heights.”
Fig. 3
WINDNOVATION™
E WIND POWER TO A HIGHER LEVEL
Lawrence L Stewart All Rights Reserved
Wind Energy Industry Recognizes Need to Reduce Costs:
Within the wind industry, there is a call for reducing the cost of wind. Timothy Morris, AWEA's Director of
ith five year PTC extension stability and recent state RPS increases in place, wind manufacturers,
developers, and service providers now have the opportunity to pursue long term cost reduction
how much further does the cost of wind need to fall to remain
competitive in the future market?"
To reduce wind turbine installation costs, one approach is to build larger units
(7)
, as shown on Fig
“The turbine size and the type of wind power system are usually related. Today’s utility
turbine generally has three blades, sweeps a diameter of about 80 to 100 metres, has a capacity from
and is part of a wind farm of between 15 and as many as 150 turbines that are
Figure 3
the colossal
large
compared
known
Page 4 of 25
cing the cost of wind. Timothy Morris, AWEA's Director of
ith five year PTC extension stability and recent state RPS increases in place, wind manufacturers,
to pursue long term cost reduction
how much further does the cost of wind need to fall to remain
, as shown on Figure 2:
“The turbine size and the type of wind power system are usually related. Today’s utility-scale wind
, has a capacity from
and is part of a wind farm of between 15 and as many as 150 turbines that are
Figure 3
(8)
shows
the colossal size of
large wind turbines,
compared to well
known objects.
Fig. 2

5. WINDNOVATION™
TAKE WIND POWER TO A HIGHER LEVEL
© Copyright 2019 Lawrence L Stewart All Rights Reserved Page 5 of 25
Another reason for higher towers other than to just accommodate larger diameter rotors is to eliminate the
ground effect that reduces wind energy by frictional losses from the terrain. The wind energy is greater at
higher elevations above grade as shown by the DOE graphic
(9)
, Figure 4:
“… taller wind turbine
towers of 110 and 140
meters with larger rotors
can more efficiently
capture the stronger and
more consistent wind
found at greater heights,
compared with 80-meter
wind turbine towers
typically installed today.”
Figure 4.Representative
wind atmospheric
boundary layer velocity
profile with two turbines of
different heights Source:
NREL"
Figure 5, illustrates the
approach taken by
Vestas, a leading wind
turbine manufacturer, to
increase wind energy
capture by increasing
the swept rotor area and
tower height
(10)
.
According to NREL's
chief engineer at the
National Wind
Technology Center,
Paul Veers, “We haven’t
hit the barrier yet for
how large these
machines can be.”
(11)
Summarizing the preceding comments, “a taller tower allows turbines to catch faster-blowing winds at
greater distances from the ground. When combined, these trends enable the turbine to extract more
power from the wind.”
(12)
Can it be concluded that the future success of the wind industry is to simply
build bigger and taller machines?
According to Henrik Stiesdal, Chief Technology Officer at Siemens Wind
(13)
, it may not be possible to
build the bigger machines.
“The amount of energy a turbine could generate doubled every four years from 1980 to 2003,
Stiesdal said. In the past ten years, however, the generation capacity of land-based turbines grew
only marginally, or remained steady.
Two major factors still challenge turbine size, Stiesdal said. First, local authorities sometimes
impose tip-height restrictions on turbines. And eventually, he says, the weight of turbines could
negate any energy gains.
"The weight goes up cubed, but the energy capture only goes up squared," he said.”
Fig. 4
Fig. 5
Fig. 5

6. TAKE
© Copyright 2019 Lawrence L Stewart All Rights Reserved
As of September 2018,
the largest wind turbine
is the 9.5 MW MHI-
Vestas V164
(14)
, but its
164 m rotor diameter is
dwarfed by Adwen’s 8
MW
(15)
AD-180 size of
180m (590.6’) with a
blade length of 88.4m
(290’), exceeding the
total wing-span of a
Boeing 747 by 28.66m
(94’). For an idea of the
huge size, the LM 88.4
blade can be seen in the
adjacent photo, Figure
6, as it exits the factory.
There should be concern that the Adwen length may be approaching the limit of blade length due to
the road transportation challenges for making turns.
What would it take to increase the generation capacity to 12 MW for the AD
references:
 The generation capacity is based on the swept rotor area.
 The weight increases as a cube, the energy capture squared.
Assuming power generated is directly proportional to the energy, a 50% increase requires the swept rotor
area to increase by 50%, which requires a diameter of 220.5m (723’). The energy capture is 50% higher.
The weight increases by 83%, which means roughly that the turbine cost is 83% h
increase. For 16 MW, cost is 183% for 100% higher generation capacity. Contrary to Paul Veer’s
comment quoted earlier that the barrier in blade size has not been hit, the diminishing return on bigger
machines is apparent, which explains the lack of any larger turbines announced since 2014.
However, GE recently announced plans for a 12 MW turbine
being addressed by Rahul Yarala, executive director of the Wind Technology Testing Center,
investigating, “whether blades can be built in segments instead of as a single piece
As noted by Brian Clark Howard
(17)
:
“Bigger blades may not be as important as higher towers
energy production is wind velocity
turbulence and ground drag. A higher tower means more wind but it is more expensive to build, so
designers usually try to optimize them with the biggest turbine that will fit
The better approach then is to go higher with the same swept area if cost allowed. One concept is to go
fly a kite:
“Companies like Makani, Magenn
get even higher, into stronger winds than the tallest towers. They are at early testing phases, but
already entrepreneurs have been pitching fleets of high turbines lofted by boats or anchored
sea floor or desert bedrock.”
(18
The hazard of a high elevation multi MW kite breaking its ether and the subsequent crashing of the
machine and its cabling and tether lines must not be ignored.
Challenges and novel concepts aside, both bigger an
to the next level, Windnovation™.
WINDNOVATION™
E WIND POWER TO A HIGHER LEVEL
Lawrence L Stewart All Rights Reserved
There should be concern that the Adwen length may be approaching the limit of blade length due to
the road transportation challenges for making turns.
uld it take to increase the generation capacity to 12 MW for the AD-180? Based on the above
s based on the swept rotor area.
The weight increases as a cube, the energy capture squared.
ectly proportional to the energy, a 50% increase requires the swept rotor
area to increase by 50%, which requires a diameter of 220.5m (723’). The energy capture is 50% higher.
The weight increases by 83%, which means roughly that the turbine cost is 83% higher for a 50% power
increase. For 16 MW, cost is 183% for 100% higher generation capacity. Contrary to Paul Veer’s
comment quoted earlier that the barrier in blade size has not been hit, the diminishing return on bigger
ns the lack of any larger turbines announced since 2014.
However, GE recently announced plans for a 12 MW turbine
(16)
. The issue of transporting long blades is
Rahul Yarala, executive director of the Wind Technology Testing Center,
blades can be built in segments instead of as a single piece”.
:
“Bigger blades may not be as important as higher towers. The most important factor in wind
energy production is wind velocity… average wind speed increases steadily with height, owing to less
turbulence and ground drag. A higher tower means more wind but it is more expensive to build, so
designers usually try to optimize them with the biggest turbine that will fit….”
approach then is to go higher with the same swept area if cost allowed. One concept is to go
Magenn, and KiteGen have been researching kite-lofted wind turbines that
get even higher, into stronger winds than the tallest towers. They are at early testing phases, but
already entrepreneurs have been pitching fleets of high turbines lofted by boats or anchored
8)
The hazard of a high elevation multi MW kite breaking its ether and the subsequent crashing of the
machine and its cabling and tether lines must not be ignored.
Challenges and novel concepts aside, both bigger and higher can be accomplished to take wind energy
Page 6 of 25
There should be concern that the Adwen length may be approaching the limit of blade length due to over
180? Based on the above
ectly proportional to the energy, a 50% increase requires the swept rotor
area to increase by 50%, which requires a diameter of 220.5m (723’). The energy capture is 50% higher.
igher for a 50% power
increase. For 16 MW, cost is 183% for 100% higher generation capacity. Contrary to Paul Veer’s
comment quoted earlier that the barrier in blade size has not been hit, the diminishing return on bigger
ns the lack of any larger turbines announced since 2014.
The issue of transporting long blades is
Rahul Yarala, executive director of the Wind Technology Testing Center, who is
. The most important factor in wind
average wind speed increases steadily with height, owing to less
turbulence and ground drag. A higher tower means more wind but it is more expensive to build, so
approach then is to go higher with the same swept area if cost allowed. One concept is to go
lofted wind turbines that
get even higher, into stronger winds than the tallest towers. They are at early testing phases, but
already entrepreneurs have been pitching fleets of high turbines lofted by boats or anchored to the
The hazard of a high elevation multi MW kite breaking its ether and the subsequent crashing of the
to take wind energy
Fig. 6

7. TAKE
© Copyright 2019 Lawrence L Stewart All Rights Reserved
Wind Turbine Design and Nomenclature
Before proceeding further it is appropriate to describe the current practice of the industry and identify the
parts comprising the wind turbine.
Wind Turbines capture wind energy to drive machinery. When connected to an electrical generator, the
wind energy is converted to electrical power.
axis wind turbine, HAWT, and vertical axis wind turbines, VAWT.
At this time the most commonly applied c
comprises a horizontally mounted AC generator located atop a tower and powered by
rotating blades. These towers can be massive, exceeding 100
5.075 MW Thornton Banks Phase 1 Wind turbines are 157 m (515') high with 126 m
(414') rotor diameter
(19)
. The towers are costly due to the structural requirements for
the heavy generator and the control system and gearing to ma
Figure 7 to the left, shows the phase 1 Thornton Banks Offshore wind farm, using
REpower 5M turbines, in the North Sea off the coast of Belgium
To reduce structural requirements, V
in development. The technology ha
acceptance. The following excerpt is
"Vertical-axis wind turbines (VAWTs)
rotor shaft is set transverse to the wind (but not necessarily
main components are located at the base of the turbine. This arrangement allows
the generator and gearbox to be located close to the ground, facilitating service
and repair. VAWTs do not need to be pointed into the wind,
need for wind
A VAWT tipped sideways, with the axis perpendicular to the wind streamlines,
functions similarly. A more general term that includes this option is "transverse
axis wind turbine" or "cross
Figure 8 shows the world's tallest vertical
While other variations of wind turbine designs exist, t
remainder of this paper focuses on the HAWT.
Wind Turbine Components
The conventionally designed HAWT
essentially to the following description and illustration
"Parts of a Wind Turbine
(23)
See Figure 9
Wind turbines come in many sizes and con
and are built from a wide range of materials. In simple
terms, a wind turbine consists of a rotor
shaped blades attached to a hub; a
a drive-train consisting of a gearbox
support bearings, the generator, plus other machinery;
a tower; and ground-mounted electrical equipment.
The wing shaped blades on the rotor actually harvest
the energy in the wind stream. The rotor converts the
kinetic energy in the wind to rotational energy trans
mitted through the drivetrain to the generator.
Fig. 8
WINDNOVATION™
E WIND POWER TO A HIGHER LEVEL
Lawrence L Stewart All Rights Reserved
Wind Turbine Design and Nomenclature
Before proceeding further it is appropriate to describe the current practice of the industry and identify the
Wind Turbines capture wind energy to drive machinery. When connected to an electrical generator, the
converted to electrical power. Two types of wind turbine designs are prevalent, horizontal
tical axis wind turbines, VAWT.
At this time the most commonly applied configuration is the HAWT design, which
comprises a horizontally mounted AC generator located atop a tower and powered by
rotating blades. These towers can be massive, exceeding 100 feet in height; e.g., the
5.075 MW Thornton Banks Phase 1 Wind turbines are 157 m (515') high with 126 m
. The towers are costly due to the structural requirements for
the heavy generator and the control system and gearing to match the grid frequency.
shows the phase 1 Thornton Banks Offshore wind farm, using
in the North Sea off the coast of Belgium
(20)
.
, Vertical Axis Wind Turbines (VAWT) designs are
The technology has yet to advance to the point of general
cerpt is from the Wikipedia Internet site
(21)
.
axis wind turbines (VAWTs) are a type of wind turbine
rotor shaft is set transverse to the wind (but not necessarily vertically) while the
main components are located at the base of the turbine. This arrangement allows
the generator and gearbox to be located close to the ground, facilitating service
and repair. VAWTs do not need to be pointed into the wind, which remove
need for wind-sensing and orientation mechanisms….
A VAWT tipped sideways, with the axis perpendicular to the wind streamlines,
functions similarly. A more general term that includes this option is "transverse
axis wind turbine" or "cross-flow wind turbine."
8 shows the world's tallest vertical-axis wind turbine, Cap
s of wind turbine designs exist, the horizontal axis turbine is the mo
remainder of this paper focuses on the HAWT.
HAWT conforms
essentially to the following description and illustration
See Figure 9
turbines come in many sizes and con-figurations
and are built from a wide range of materials. In simple
rotor that has wing
; a nacelle that houses
gearbox, connecting shafts,
, plus other machinery;
mounted electrical equipment.
The wing shaped blades on the rotor actually harvest
the energy in the wind stream. The rotor converts the
ind to rotational energy trans-
to the generator.
Fig. 9
Page 7 of 25
Before proceeding further it is appropriate to describe the current practice of the industry and identify the
Wind Turbines capture wind energy to drive machinery. When connected to an electrical generator, the
Two types of wind turbine designs are prevalent, horizontal
wind turbine where the main
vertically) while the
main components are located at the base of the turbine. This arrangement allows
the generator and gearbox to be located close to the ground, facilitating service
which removes the
A VAWT tipped sideways, with the axis perpendicular to the wind streamlines,
functions similarly. A more general term that includes this option is "transverse
axis wind turbine, Cap-Chat, Quebec
(22)
he horizontal axis turbine is the most prevalent. The
Fig. 7

8. WINDNOVATION™
TAKE WIND POWER TO A HIGHER LEVEL
© Copyright 2019 Lawrence L Stewart All Rights Reserved Page 8 of 25
Generated electricity can be connected directly to the load or feed to the utility grid.
The weight and cost of the turbine is the key to making wind energy.”
A Breakdown of Wind Turbine Costs
(24)
Figure 10 (referenced document figure 4.4) shows a general cost breakdown for an offshore wind turbine.
“The two most expensive components are the towers and rotor blades, with these contributing around half
of the total cost. After these two components, the next largest cost component is the gearbox. But this
underestimates the importance of gearboxes, as these generally are an important part of the O&M costs,
as they can require extensive maintenance. Onshore wind turbines, with their smaller sizes, will tend to
have slightly lower shares for the tower and blades.
"A typical wind turbine will contain up to 8000 different components. This guide shows the main parts and
their contribution in percentage terms to the overall cost. Figures are based on a REpower MM92 turbine
with 45.3 metre length blades and a 100 metre tower.
A. Tower (26.3%): Range in height from 40 metres up to more
than 100 m. Usually manufactured in sections from rolled steel;
a lattice structure or concrete are cheaper options.
B. Rotor blades (22.2%): Varying in length up to more than 60
metres, blades are manufactured in specially designed moulds
from composite materials, usually a combination of glass fibre
and epoxy resin. Options include polyester instead of epoxy
and the addition of carbon fibre to add strength and stiffness
C. Rotor Hub (1.37%): Made from cast iron, the hub holds the
blades in position as they turn
D. Rotor Bearings (1.22%): Some of the many different bearings
in a turbine. These have to withstand the varying forces and
loads generated by the wind.
E. Main shaft (1.91%): Transfers the rotational force of the rotor
to the gear box.
F. Main Frame (2.80%): Made from steel, must be strong enough
to support the entire turbine drivetrain, but not too heavy.
G. Gearbox (12.91%): Gears increase the low rotational speed of
the rotor shaft in several stages to the high speed needed to
drive the generator.
H. Generator (3.44%): Converts mechanical energy into electrical
energy. Both synchronous and asynchronous generators are
used.
I. Yaw System (1.25%): Mechanism that rotates the nacelle to
face the changing wind direction.
J. Pitch System (2.66%): Adjusts the angle of the blades to
make best use of the prevailing wind.
K. Power Converter (5.01%): Converts direct current from the
generator into alternating current to be exported to the grid
network.
L. Transformer (3.59%): Converts the electricity from the turbine
to higher voltage required by the grid.
M. Brake system (1.32%): Disc brakes bring the turbine to a halt
when required.
N. Nacelle housing (1.35%): Light glass fibre box covers the
turbine drivetrain.
O. Screws (1.04%): Hold the main components in place, must be
designed for extreme loads.
P. Cables (0.96%): Link individual turbines in a wind farm to an
electricity substation.
Fig. 10

9. WINDNOVATION™
TAKE WIND POWER TO A HIGHER LEVEL
© Copyright 2019 Lawrence L Stewart All Rights Reserved Page 9 of 25
Quoting from "Renewable Energy Technologies: Cost Analysis Series", "The key cost reduction areas for
wind turbines (Douglas-Westwood, 2010) are
(25)
:
 "Towers: These are an important part of the wind turbine cost (up to one quarter), but are a relatively
mature component. Most are rolled steel, with costs being driven by steel prices. However,
increased competition, the integration of lightweight materials and the more distributed location of
manufacturers that will be possible as markets expand means tower costs may come down, perhaps
by 15% to 20% by 2030.
 Blades: Wind turbine rotor blades can account for one-fifth of turbine costs. The key driver behind
blade design evolution is weight minimization as this reduces loads and helps improve efficiency.
Using more carbon fibre in blades, as well as improving the design of blades (with production
efficiency and aerodynamic efficiency in mind) can help reduce weight and costs, although the high
cost of carbon fibre is a problem. Cost reductions of 10% to 20% could be possible by 2020.
 Gearboxes: Typically represent 13% to 15% of wind turbine costs The R&D focus for gearboxes is to
improve reliability and reduce costs. Vertical integration of gearbox manufacturing by wind turbine
suppliers should help reduce costs. Cost reductions may also stem from the increasing share of
gearless drive generators using permanent magnet synchronous motors. Overall, cost reductions
could reach 15% by 2020.
 Other components: The most significant remaining components are the generator, control systems
(including pitch and yaw systems), transformer and power converter. These components, as well as
the other miscellaneous components of the turbine, all have opportunities for cost reductions through
increased manufacturing efficiency and R&D efforts. These components could see cost reductions of
10% to 15% by 2020."
The preceding text has been provided
to describe the parts of a wind turbine.
Table 1 is compiled from the cost and
weight information provided by
Douglas-Westwood in the above text
and the values associated with Figures
9 and 10.
The goal is to go bigger and higher,
which is difficult as the system weight
and allowable dynamic loads are
approaching the limit of structural
properties.
The targets for weight reduction are
the nacelle and gearbox, which would
allow the tower height to be increased
for the same weight of the tower.
Innovative approaches to reduce the
weights of the Nacelle, Gearbox and
Drivetrain, and generator systems are
described in the following text.
TABLE 1
WIND TURBINE APPROXIMATE COST AND WEIGHT BREAKDOWN, %
COMPONENT COST COST)
WEIGHT)
TOWER 26.3 10 - 25 30 - 65
ROTOR 27.5 20 - 30 10 -14
Rotor Blades
.2
Rotor Hub 1.4
Rotor Bearings 1.2
Pitch System 2.7
GEARBOX AND DRIVETRAIN 14.8 10 - 15 5 - 15
Main Shaft 1.9
Gearbox 12.9
GENERATOR SYSTEMS 12.0 5 -15 2 - 6
Generator 3.4
Power Converter 5.0
Transformer 3.6
NACELLE AND MACHINERY 19.4 25 25 - 40
Nacelle Housing 1.4
Brake System 1.3
Main Frame 2.8
Yaw System 1.3
Cables 1.0
Screws 1.0
Miscellaneous* 10.7
TOTAL 100.0 100 100
*Item added to account for 89.3% total from the referenced published table

10. TAKE
© Copyright 2019 Lawrence L Stewart All Rights Reserved
INNOVATION IS A NECESSITY
“Disruptive Innovation” was coined by Clayton Christensen in his various books to describe market and
technological change that unless recognized and heeded result in the failure of major companies. He
analyzed the demise of industry giants such as Sears
business, concluding they failed to adapt to both the technology advances and market demands in their
respective industry. Christensen states in his book,
“Technology Strategy for Disruptive Innovations”:
“Our technology plan cannot call for any the technological breakthroughs on the path critical for the
project’s success. Historically, disruptive technologies involve no new technologies; rather, they con
of components built around proven technologies and put together in a novel product architecture that
offers the customer a set of attributes never before available."
In keeping with the above observation, both technology and processes exist for subst
electrical power generation from wind energy. It is possible to
MW/acre with little if any increase in costs. The remainder of this paper will describe this substantial
improvement.
Challenges and novel concepts aside, both bigger and higher can be accomplished
BLADE DESIGN
Christensen’s “disruptive technologies involve no new technologies; rather, they consist of components
built around proven technologies” applies to blad
craft and fan design. The rationale for this approach is supported by comparing Betz’s Law
illustrated by the schematic as shown in Figure 11 to the equivalent for an axial flow fan,
Castegnaro
(27)
shows the mirror image for an open flow
axial flow fan. The air travels though the fan
as energy is added, the air is compacted to a smaller
area.
Considering the above, aircraft, propeller and fan technology should apply to Wind Turbine engineering.
Fig. 11
WINDNOVATION™
E WIND POWER TO A HIGHER LEVEL
Lawrence L Stewart All Rights Reserved
“Disruptive Innovation” was coined by Clayton Christensen in his various books to describe market and
technological change that unless recognized and heeded result in the failure of major companies. He
analyzed the demise of industry giants such as Sears in retail sales and Digital in the storage media
business, concluding they failed to adapt to both the technology advances and market demands in their
respective industry. Christensen states in his book, The Innovator’s Dilemma, under the heading,
“Technology Strategy for Disruptive Innovations”:
“Our technology plan cannot call for any the technological breakthroughs on the path critical for the
project’s success. Historically, disruptive technologies involve no new technologies; rather, they con
of components built around proven technologies and put together in a novel product architecture that
offers the customer a set of attributes never before available."
In keeping with the above observation, both technology and processes exist for substantial increase in
electrical power generation from wind energy. It is possible to substantially increase the power output per
MW/acre with little if any increase in costs. The remainder of this paper will describe this substantial
es and novel concepts aside, both bigger and higher can be accomplished, Windnovation
disruptive technologies involve no new technologies; rather, they consist of components
” applies to blade design. The proven technology that is applicable is air
craft and fan design. The rationale for this approach is supported by comparing Betz’s Law
as shown in Figure 11 to the equivalent for an axial flow fan,
Betz' law shows that as air flows through a turbine, it slows
from losing energy and must spread out to a wider area.
he mirror image for an open flow
. The air travels though the fan blades and
as energy is added, the air is compacted to a smaller
Petrov states, “A propeller (axial fan rotor) and a
wind turbine rotor are completely reversible. They
are described by the same basic theoretical
considerations”, illustrated by Figure 13
Considering the above, aircraft, propeller and fan technology should apply to Wind Turbine engineering.
Fig. 13
Page 10 of 25
“Disruptive Innovation” was coined by Clayton Christensen in his various books to describe market and
technological change that unless recognized and heeded result in the failure of major companies. He
in retail sales and Digital in the storage media
business, concluding they failed to adapt to both the technology advances and market demands in their
, under the heading,
“Our technology plan cannot call for any the technological breakthroughs on the path critical for the
project’s success. Historically, disruptive technologies involve no new technologies; rather, they consist
of components built around proven technologies and put together in a novel product architecture that
antial increase in
the power output per
MW/acre with little if any increase in costs. The remainder of this paper will describe this substantial
Windnovation™.
disruptive technologies involve no new technologies; rather, they consist of components
e design. The proven technology that is applicable is air
craft and fan design. The rationale for this approach is supported by comparing Betz’s Law
(26)
, usually
as shown in Figure 11 to the equivalent for an axial flow fan, Figure 12:
Betz' law shows that as air flows through a turbine, it slows
must spread out to a wider area.
A propeller (axial fan rotor) and a
wind turbine rotor are completely reversible. They
are described by the same basic theoretical
illustrated by Figure 13
(28)
.
Considering the above, aircraft, propeller and fan technology should apply to Wind Turbine engineering.
Fig. 12

11. TAKE
© Copyright 2019 Lawrence L Stewart All Rights Reserved
Blades are usually treated as aircraft wings
practices of the aircraft industry for wing and propellers to improve wind turbine performance.
Described very simply, the blade is a rotating member, same as a propeller. The resulting centrifugal
force works to push the air to the blad
the root and narrow at the tip. The energy captured from the wind is dependent upon the area of the wing
surface. For a number of reasons, primarily structural, blades are tapered.
keep the air flow massed as close as possible to the largest surface area, i.e. across the root chord,
Following illustrations show methods to control the air flow for more efficient lift on aircraft wings, i.e.
energy capture.
As shown on the X-29 photo
(30)
, Figure 14, the
wings are reversed swept. The purpose of the
reverse swept wing
(31)
, shown in Figure 15,
channel the air inwardly, A, to maintain airflow
across the airfoil and minimize the centrifugally
created radial flow across the surface
Fig. 15
A
.
B
.
Longer chord
Fig. 16
WINDNOVATION™
E WIND POWER TO A HIGHER LEVEL
Lawrence L Stewart All Rights Reserved
Blades are usually treated as aircraft wings
(29)
. The following discussion looks at incorporating the
practices of the aircraft industry for wing and propellers to improve wind turbine performance.
Described very simply, the blade is a rotating member, same as a propeller. The resulting centrifugal
force works to push the air to the blade tip. Current blade design employs a wing design which is large at
the root and narrow at the tip. The energy captured from the wind is dependent upon the area of the wing
For a number of reasons, primarily structural, blades are tapered. It would see more effective to
keep the air flow massed as close as possible to the largest surface area, i.e. across the root chord,
Following illustrations show methods to control the air flow for more efficient lift on aircraft wings, i.e.
Figure 14, the
wings are reversed swept. The purpose of the
, shown in Figure 15, is to
to maintain airflow
across the airfoil and minimize the centrifugally
dial flow across the surface, B.
Another approach to minimize the loss of lift from the
outwardly lateral flow of air along the swept wing was
to increase the chord of the wing tip as found on the
XF-91 Thunderceptor
(32)
, Fig 16. This design
concentrated more lifting surface at the tip to
compensate for the loss in energy resulting from the
lateral flow of air
Longer chord
Page 11 of 25
incorporating the
practices of the aircraft industry for wing and propellers to improve wind turbine performance.
Described very simply, the blade is a rotating member, same as a propeller. The resulting centrifugal
e tip. Current blade design employs a wing design which is large at
the root and narrow at the tip. The energy captured from the wind is dependent upon the area of the wing
ould see more effective to
keep the air flow massed as close as possible to the largest surface area, i.e. across the root chord,
Following illustrations show methods to control the air flow for more efficient lift on aircraft wings, i.e.
nother approach to minimize the loss of lift from the
outwardly lateral flow of air along the swept wing was
to increase the chord of the wing tip as found on the
This design
concentrated more lifting surface at the tip to
compensate for the loss in energy resulting from the
Fig. 14

12. TAKE
© Copyright 2019 Lawrence L Stewart All Rights Reserved
This innovation in wing design may have been borrowed
from the same concept to move the larger chord radially
outward, which had been applied earlier in WWII to
design more efficient propellers. The P
Figure 17
(33)
, used the Paddle Blade propeller for
increased power, "Introduction of the paddle blade prop
enabled the thunderbolt amazing climbing and turning
ability."
(34)
The design improvements of propellers and wings for
optimal energy have culminated in the airfoil geometry
to direct the air flow to the maximum chord area. The
energy efficiency has been improved further by the
introduction of the Scimitar propeller blade
Figure 19
(36)
. The design places incre
area to the periphery to maximize air flow. The curve
of the blade works to keep the air flow parallel to the
chord length for maximum effect.
Fig. 20
WINDNOVATION™
E WIND POWER TO A HIGHER LEVEL
Lawrence L Stewart All Rights Reserved
This innovation in wing design may have been borrowed
concept to move the larger chord radially
outward, which had been applied earlier in WWII to
design more efficient propellers. The P-47 Thunderbolt,
, used the Paddle Blade propeller for
Introduction of the paddle blade prop
thunderbolt amazing climbing and turning
Variations in the propeller designs are shown in
Figure 1
(35)
. As can be seen, the Paddle Blade
design, center, had increased blade area over
the original propeller on the right. It had less area
at the root than the Hamilton design on the left
and an asymmetrical profile about the radius to
more efficiently move the air for the same power.
The design improvements of propellers and wings for
optimal energy have culminated in the airfoil geometry
to direct the air flow to the maximum chord area. The
energy efficiency has been improved further by the
introduction of the Scimitar propeller blade, shown in
. The design places increased surface
area to the periphery to maximize air flow. The curve
of the blade works to keep the air flow parallel to the
The application of the Scimitar is shown in Figure 20
on a Grumman E-2C with the eight blade scimitar
propeller
(37)
. The photo illustrates one of many
Scimitar propellers now in use on aircraft around the
world.
Fig. 18
Fig. 19
Page 12 of 25
propeller designs are shown in
. As can be seen, the Paddle Blade
design, center, had increased blade area over
propeller on the right. It had less area
at the root than the Hamilton design on the left
and an asymmetrical profile about the radius to
more efficiently move the air for the same power.
The application of the Scimitar is shown in Figure 20
eight blade scimitar
. The photo illustrates one of many
Scimitar propellers now in use on aircraft around the
Fig. 17

13. TAKE
© Copyright 2019 Lawrence L Stewart All Rights Reserved
PRACTICE OF THE INDUSTRY
Power Generation
Power generating facilities are designed to the traditional
been used since the time of Edison, i.e. generate electricity to match grid parameters of frequency and
voltage. In the United States, frequency is 60 Hz and, depending on the point of transmission and
distribution, voltage varies from 300KV to 120V. Electrical power is conventionally carried by high voltage
overhead transmission cables, incurring substantial resistive power losses, su
towers. Each wind turbine is designed to match th
present the most efficient operation of power
Betz’s Law
The stone wall to capture wind energy is Betz’s
can be extracted from wind. “Wind turbines convert around 45% of the wind passing through the blades
into electricity (and almost 50% at peak efficiency
part of the Betz energy, i.e. 80% of 59.3%, 47.44% of the wind energy. The amount for improvement is
the difference between the ideal and actual performance, 59.3%
may be beyond practical engineering, i.e. the costs may be way past the point of diminishing return.
Nevertheless, the innovative concepts presented in this paper can push the envelope to achieve the
maximum energy capture allowed by Betz, i.e.:
1. Wind Power Generation Parameters
components and system integration to reduce energy losses.
2. Weight Reduction- lower weight allows higher hub heights to exploit the wind law that power
varies by the cube of the velocity
3. Geometry Reconfiguration-
Wind Power Generation Parameters
CONVERT WIND POWER TO GENERATE
The practice of the industry for all wind power generation facilities is to generate power to match the grid
parameters of frequency and voltage.
point of transmission and distributio
transformer, Figure 10, to boost its voltage to the Wind Farm's own power grid voltage, typically medium
voltage such as 13.5 KV. The individual machines are cabled to a collector substation where
voltage power is boosted to the grid voltage for transmission.
The typical power path is as described by Suhas Sarkar
“In a wind farm each turbine
generator feeds to the low voltage
side of a step-up transformer, either
directly, or through an electronic
power converter. In the modern wind
power plants Type 4 (variable speed
turbines with full power electronics
converter) systems are commonly
applied these days, which feed their
output to AC-DC-AC converter, which
in turn feeds the wind turbine gen-
erator step-up (WTGSU) transformer.
Fig. 1 (Figure 21) shows a single-line
diagram of wind power generation.”
WINDNOVATION™
E WIND POWER TO A HIGHER LEVEL
Lawrence L Stewart All Rights Reserved
Power generating facilities are designed to the traditional alternating current electrical paradigm that has
been used since the time of Edison, i.e. generate electricity to match grid parameters of frequency and
voltage. In the United States, frequency is 60 Hz and, depending on the point of transmission and
ribution, voltage varies from 300KV to 120V. Electrical power is conventionally carried by high voltage
overhead transmission cables, incurring substantial resistive power losses, suspended from
Each wind turbine is designed to match the grid power parameters. This practice
present the most efficient operation of power energy generation from wind energy.
The stone wall to capture wind energy is Betz’s Law
(38)
, which states 59.3% is the maximum power that
“Wind turbines convert around 45% of the wind passing through the blades
into electricity (and almost 50% at peak efficiency).”
(39)
A wind turbine operating at 80% captures that
part of the Betz energy, i.e. 80% of 59.3%, 47.44% of the wind energy. The amount for improvement is
the difference between the ideal and actual performance, 59.3% - 47.5%. The resulting available 11.9%
be beyond practical engineering, i.e. the costs may be way past the point of diminishing return.
Nevertheless, the innovative concepts presented in this paper can push the envelope to achieve the
maximum energy capture allowed by Betz, i.e.:
n Parameters- incorporate improvements in the design of the individual
components and system integration to reduce energy losses.
lower weight allows higher hub heights to exploit the wind law that power
velocity
redesign components for greater efficiency.
ters
ENERATE DIRECT CURRENT POWER
The practice of the industry for all wind power generation facilities is to generate power to match the grid
parameters of frequency and voltage. In the United States, frequency is 60 Hz and, depending on the
point of transmission and distribution, voltage varies from 765KV to 120V. Each wind turbine co
to boost its voltage to the Wind Farm's own power grid voltage, typically medium
voltage such as 13.5 KV. The individual machines are cabled to a collector substation where
voltage power is boosted to the grid voltage for transmission.
The typical power path is as described by Suhas Sarkar
(40)
:
up transformer, either
power converter. In the modern wind
power plants Type 4 (variable speed
applied these days, which feed their
AC converter, which
up (WTGSU) transformer.
line
diagram of wind power generation.”
Fig. 21
Page 13 of 25
alternating current electrical paradigm that has
been used since the time of Edison, i.e. generate electricity to match grid parameters of frequency and
voltage. In the United States, frequency is 60 Hz and, depending on the point of transmission and
ribution, voltage varies from 300KV to 120V. Electrical power is conventionally carried by high voltage
spended from unsightly
ractice does not
which states 59.3% is the maximum power that
“Wind turbines convert around 45% of the wind passing through the blades
A wind turbine operating at 80% captures that
part of the Betz energy, i.e. 80% of 59.3%, 47.44% of the wind energy. The amount for improvement is
47.5%. The resulting available 11.9%
be beyond practical engineering, i.e. the costs may be way past the point of diminishing return.
Nevertheless, the innovative concepts presented in this paper can push the envelope to achieve the
incorporate improvements in the design of the individual
lower weight allows higher hub heights to exploit the wind law that power
The practice of the industry for all wind power generation facilities is to generate power to match the grid
In the United States, frequency is 60 Hz and, depending on the
e varies from 765KV to 120V. Each wind turbine contains a
to boost its voltage to the Wind Farm's own power grid voltage, typically medium
voltage such as 13.5 KV. The individual machines are cabled to a collector substation where the medium

14. TAKE
© Copyright 2019 Lawrence L Stewart All Rights Reserved
Compounded energy inefficiencies in this train of AC to DC to AC
in equipment. Diaz reported 27 MVAR
a 159 MW site. Assuming the same efficiency for the DC motor
AC Inverter train, the inductive loss of 1.5 MW of
This more efficient and cost effective site power design is illustrated below.
The layout is for simplified for illustration
turbines would be governed by the wind profile and topography with sufficient distance between machines
for optimum energy recovery, considering the 9° conical shaped wake
The advantages provided by this approach to more efficient power
1. Electrical generation is direct current, DC, originating with the wind turbine and through the system
until final conversion to match Grid AC parameters.
a. DC power from all machines is conducted to central DC Motor AC Generator set(s) or Inverter(s)
for conversion to Grid voltage and frequency.
b. Simpler machinery, controls, and cabling.
c. Lower capital, operating, and maintenance costs
2. Individual Wind Turbine voltage is controlled to match bus, current maximized. Silicon Diode Array, or
other suitable device, is installed to prevent current reversal from the wind farm interconnect network.
3. Complex control system to maintain output freque
4. Pitch and speed of the blades are controlled to maximize voltage not precisely match grid frequency
to control power quality.
The disadvantages are:
1. DC line losses are higher for the
2. To minimize transmission losses, site voltages would be 12.47 KV
AC power for wind turbines. All DC system components would require la
insulation, possibly offsetting the cost saved by emanation of the va
Each site would require evaluation based on site specific parameters as to whether the conventional AC
system is better or the DC system described above.
Dwg. 1
WINDNOVATION™
E WIND POWER TO A HIGHER LEVEL
Lawrence L Stewart All Rights Reserved
ompounded energy inefficiencies in this train of AC to DC to AC can be reduced, as well as saving cost
7 MVAR
(41)
of reactive losses for the WTGSU and collector transformers
. Assuming the same efficiency for the DC motor – AC Generator as for the typical A
s of 1.5 MW of would be eliminated, adding 1% more power to the grid.
This more efficient and cost effective site power design is illustrated below.
illustration purpose. The placement and spacing of the individual
wind profile and topography with sufficient distance between machines
considering the 9° conical shaped wake discussed by Attias
The advantages provided by this approach to more efficient power generation are:
Electrical generation is direct current, DC, originating with the wind turbine and through the system
until final conversion to match Grid AC parameters.
DC power from all machines is conducted to central DC Motor AC Generator set(s) or Inverter(s)
for conversion to Grid voltage and frequency.
Simpler machinery, controls, and cabling.
ower capital, operating, and maintenance costs for fewer components.
Individual Wind Turbine voltage is controlled to match bus, current maximized. Silicon Diode Array, or
other suitable device, is installed to prevent current reversal from the wind farm interconnect network.
Complex control system to maintain output frequency to match grid frequency is not needed.
Pitch and speed of the blades are controlled to maximize voltage not precisely match grid frequency
DC line losses are higher for the same power as AC.
e transmission losses, site voltages would be 12.47 KV – 22.5 KV versus the usual 600 V
AC power for wind turbines. All DC system components would require larger conductors and greater
, possibly offsetting the cost saved by emanation of the various AC-DC conversion devices
Each site would require evaluation based on site specific parameters as to whether the conventional AC
system is better or the DC system described above.
Page 14 of 25
can be reduced, as well as saving cost
collector transformers on
AC Generator as for the typical AC-DC-
, adding 1% more power to the grid.
of the individual wind
wind profile and topography with sufficient distance between machines
discussed by Attias
(42)
.
Electrical generation is direct current, DC, originating with the wind turbine and through the system
DC power from all machines is conducted to central DC Motor AC Generator set(s) or Inverter(s)
Individual Wind Turbine voltage is controlled to match bus, current maximized. Silicon Diode Array, or
other suitable device, is installed to prevent current reversal from the wind farm interconnect network.
ncy to match grid frequency is not needed.
Pitch and speed of the blades are controlled to maximize voltage not precisely match grid frequency
22.5 KV versus the usual 600 V
ger conductors and greater
DC conversion devices.
Each site would require evaluation based on site specific parameters as to whether the conventional AC

15. WINDNOVATION™
TAKE WIND POWER TO A HIGHER LEVEL
© Copyright 2019 Lawrence L Stewart All Rights Reserved Page 15 of 25
BIGGER IS BETTER
As noted in the introductory text, the industry has established that larger Wind Machines are more
economical. In order to build machines larger than 8 MW, innovation is required to improve system
efficiency and increase hub height. These innovations are described in the following discussion.
REDUCE NACELLE WEIGHT - INCREASE HUB HEIGHT
Quoting from "A review of offshore wind turbine nacelle: Technical challenges, and research and
developmental trends"
(43)
:
"The turbine nacelle with traditional wind power generation system is heavy, especially in offshore
applications due to the large mass of the power frequency step-up-transformer operated at 50 or
60 Hz, and copper conductor generator. For example, the weight and volume of a 0.69/33 kV 2.6
MVA transformer is typically in the range of 6–8 t and 5–9 m3, respectively. The weight for a 10
MW direct drive permanent magnet generator is about 300 t. These penalties significantly
increase the tower construction, and turbine installation and maintenance costs. The tower cost
represents 26% of the total component cost of the turbine and on average about 20% of the
capital costs are associated with installation. Typical maintenance cost of an offshore wind
turbine is about 2.3 cents/kWh, which is 20% higher than that of an onshore based turbine. As
alternative approaches to achieve a compact and lightweight offshore wind turbine nacelle,
different concepts have been proposed in recent years, such as step-up-transformer-less system,
medium-frequency (in the range of a few kHz to MHz) power transformer-based system,
multilevel and modular matrix converter-based system and superconducting generator-based
system. This paper aims to … reduce the weight and volume of the nacelle."
The resolution of the increasing generator weights as
MW capacity grows is to relocate the generator and
associated electrical gear from the nacelle to grade.
This approach also solves the weight problem of
increased generator size as the industry seeks to build
wind machines that exceed the current 8MW ceiling:
 Structural requirements are substantially reduced,
resulting in less cost to build,
 Better maintenance access,
 Power is transmitted from the rotor shaft to the
generator by any of the following
- Mechanical gearing and shaft system,
- Hydraulic pump(s) to motor(s) system,
- Air compressor(s) to air motor(s),
- Other methods as appropriate.
Note: (1) Moving the generator to grade and employing the transfer drives as listed applies equally well
to the conventional AC generator system.
(2) The above and other innovations have been invented and covered by provisional patents,
available for detailed discussion upon execution of a non-disclosure agreement.
Relocating the generator and electrical system to grade reduces the tower head mass which enables a
proportional increase in hub height to the higher energy level of wind for essentially the same structural
steel and foundations weights.
Nacelle Fire Hazard Reduced/Eliminated
A significant improvement over the conventional design is essentially the total elimination of nacelle fires
by the relocation of the generators and power distribution systems to grade. From an article by Colin
Smith in 2014
(44)
:
Dwg. 2

16. WINDNOVATION™
TAKE WIND POWER TO A HIGHER LEVEL
© Copyright 2019 Lawrence L Stewart All Rights Reserved Page 16 of 25
"Researchers from Imperial College London, the University of Edinburgh and SP Technical
Research Institute of Sweden carried out a global assessment of the world’s wind farms, which in
total contain an estimated 200,000 turbines.
….Fire is the second leading cause of accidents in wind turbines, after blade failure, according to
research out today.
….Comparing the only data available, the team
estimate that ten times more fires are happening than
are being reported. Instead of an average of 11.7 fires
each year, which is what is reported publicly, the
researchers estimate that more than 117 separate fires
are breaking out in turbines annually.
….Wind turbines catch fire because highly flammable
materials such as hydraulic oil and plastics are in close
proximity to machinery and electrical wires. These can
ignite a fire if they overheat or are faulty. Lots of
oxygen, in the form of high winds, can quickly fan a fire
inside a turbine. Once ignited, the chances of fighting
the blaze are slim due to the height of the wind turbine
and the remote locations that they are often in.
Fire is the second leading cause of accidents in wind turbines, after blade failure, according to
research out today.” Figure 22 shows the result of a nacelle fire.
DUAL DRIVE WIND TURBINE
The design shown on Drawing 3 incorporates upwind and downwind counter rotating blades that harvest
more of the available wind energy for the individual tower site than a single rotor. The multi-rotor design
is covered by Kale
(45)
. As illustrated the design is similar to the “Counter rotating horizontal axis Wind
Turbine” described on page 3 of this paper, major difference larger diameter blades downwind to capture
the energy in the 9° conical wake
(46)
from the upwind blades and the generator located on grade.
1. Upwind and downwind power trains
2. Drives are separated for independent
operation.*
- Shaft centerlines are offset.
- Vertical shafts are concentric.
- Allows maximum power per rotor.
3. Power transfer is to Generators by
- Shaft and Mechanical Gear System.
- DC Generators preferred.
- Alternative Fluid Drive System could be used.
4. Rotor Pitch is controlled to maximize power not
speed, i.e. maintain optimum voltage not Hz.
5. Viscous coupling to accommodate wind gusts
without damage to the drivetrain.
6. Electrical power train components removed
from Nacelle. Generator, Transformers,
Inverters, and associated equipment placed at
grade or other appropriate location.
7. Blade assemblies are counter rotating for more
efficient energy capture. Further benefit is the
cancelation of moment loads to the tower and
foundations, yielding a lighter structure and
consequently the ability to increase hub height.
8. Distance between the upwind and downwind blades can provide static pressure regain for increased
energy capture. The nacelle and drive mechanisms can be designed to allow for adjustment of the
distance by a sliding sleeve of the drive shafts and nacelle cover, details omitted.
Dwg. 3
Fig. 22

17. WINDNOVATION™
TAKE WIND POWER TO A HIGHER LEVEL
© Copyright 2019 Lawrence L Stewart All Rights Reserved Page 17 of 25
*Main components only shown. Bearings, support structure, lubricating and coolant system, and
controls system omitted for clarity. Drivetrain mechanisms sizes are simplified and exaggerated.
Alternative Drive Configurations (not shown):
 Combine upwind and downwind rotors to a mechanical two drive single output shaft.
 One rotor for both up and down wind blades, control load sharing by blade pitch to match power.
IMPROVE BLADE PERFORMANCE BY ADOPTING AIRCRAFT TECHNOLOGY
Apply the airfoil technology developed for aircraft as described by Figures 11-17 and accompanying text.
1. Double ended power trains-
- More power per each nacelle
- Counter rotating blades cancel the
overturning moment of a single end.
2. “Scimitar” design Blades, adapting high
efficiency propellers used by the Airbus
A400M and Beechcraft Starship or
“Paddle” blades similar to those used in
high performance WWII aircraft.
3. Fore and aft generators designed for
maximum power, minimum overturning
torque to foundation, and prevention of
harmonics and masking:
- Counter rotating
- Different number of blades
- Distance between blades modeled for
optimum length
4. Blades are adjusted to achieve
maximum power generation for available wind
- Variable Pitch for speed control
- Fixed Tilt in the direction of the wind, coning, to shape wind stream to the center for better energy
capture and reduction of the 9° wake for optimum effect on adjacent machines
- Forward inclined blades set at the most efficient angle for optimum performance. Forward inclined
blades in the direction of rotation are quieter and more efficient at the low rotating speed associated
with wind turbines:
- The advantage of the forward curve fan is its low speed and quiet operation
(46)
.
- Nakahama stated that “forward-swept and inclined blades showed that the flow rate of cooling air
increased by 80% compared with that of conventional machines
(47)
. As a note, the Nakahama
paper covered very small fans, but the results should be considered, as a minimum, qualitatively
applicable as the Fan Laws scale up by geometry.
5. More efficient blades allow smaller blades for the same energy capture:
- Less restrictive transport due to sorter lengths,
- Less weight for higher hub height allowing operation at higher wind velocities, greater power.
SHROUDED BLADES
The purpose of shrouding blades is to direct more energy into the swept area to improve energy capture.
The benefits of shrouds to improve the performance of wind turbines are well documented.
Two examples of shrouds are shown. Figure 23 is a 35 KW wind turbine
(48)
with a 33 m diameter swept
area, installed in Rebielice, Poland in 2003, which ceased operation in 2015. Figure 24 shows a
proposed design
(49)
in Japan, where it is claimed that, “The shrouded wind turbine with a brimmed
diffuser has demonstrated power augmentation by a factor of about 2–5 compared with a bare wind
turbine.”
(50)
It should be noted that the shroud encompasses the blade tips.
Dwg. 4

18. TAKE
© Copyright 2019 Lawrence L Stewart All Rights Reserved
While the objective of increased energy capture may be achieved, there is a tremendous weight added to
the wind turbine structure, which would preclude the installation of large machines at higher elevations.
It’s difficult to think of a shroud enveloping
illustrated on Figure 3. The weight increase
more power.
For the dual drive wind turbine, Drawing 4
Fig. 23
Dwg. 5
5A
Fig. 25
WINDNOVATION™
E WIND POWER TO A HIGHER LEVEL
Lawrence L Stewart All Rights Reserved
While the objective of increased energy capture may be achieved, there is a tremendous weight added to
the wind turbine structure, which would preclude the installation of large machines at higher elevations.
It’s difficult to think of a shroud enveloping the blades of the 11 MW 190 m diameter wind turbine
gure 3. The weight increase counters the need to go higher for increased wind velocity for
However, the principle of the shroud to modify the
wind profile by creating a low pressure region
accomplished by an alternative geometry, as indicated
by Ohya
(51)
, “This is because a low-
due to a strong vortex formation behind the broad
brim, draws more mass flow to the wind turbine inside
the diffuser. This concept is more fully illustrated by
Figure 25 (Ohya Figure 5.).
(52)
This concept is similar to that employed by Presz
where it is claimed, “The MEWT (Mixer/Ejector Wind
Turbine) can produce three or more time the power of
its un-shrouded counterparts for the same frontal
area, and can increase the productivity of wind farms
by a factor of two or more.
, Drawing 4, the shroud is located between the drives, Drawing 5.
5B
Page 18 of 25
While the objective of increased energy capture may be achieved, there is a tremendous weight added to
the wind turbine structure, which would preclude the installation of large machines at higher elevations.
the blades of the 11 MW 190 m diameter wind turbine that is
the need to go higher for increased wind velocity for
However, the principle of the shroud to modify the
pressure region could be
accomplished by an alternative geometry, as indicated
-pressure region,
due to a strong vortex formation behind the broad
brim, draws more mass flow to the wind turbine inside
This concept is more fully illustrated by
This concept is similar to that employed by Presz
(53)
,
The MEWT (Mixer/Ejector Wind
Turbine) can produce three or more time the power of
shrouded counterparts for the same frontal
area, and can increase the productivity of wind farms
, Drawing 5.
Fig. 24

19. WINDNOVATION™
TAKE WIND POWER TO A HIGHER LEVEL
© Copyright 2019 Lawrence L Stewart All Rights Reserved Page 19 of 25
The airfoil geometry is designed to create a higher wind velocity inside the shroud, creating a vacuum per
the Bernoulli Effect. If the airfoil is properly designed, the shroud does not have to encompass the blade
tips per View 5A, allowing for the lower weight of a smaller shroud diameter per View 5B. The resulting
lower pressure will draw the wind stream back to the center redirecting the air from the upwind blades to
the downwind blades for more energy capture. Actual geometry requires modeling for optimization.
In views 5A and B, the shroud should be positioned after the upwind blades at 20% of the distance
between the two rotors.
The downwind rotor may also employ a larger diameter blade for increased capture of the upwind blade
air that tends to disperse radially outward from the centrifugal force of the rotating blade, the 9° wake
previously noted.
View+ 6A shows another approach to creating a higher velocity lower pressure area to draw the air
toward the center of the rotor, which is supported by above references to Ohya and Presz.
Although the proportion of the drawings are greatly exaggerated, the shrouds are nevertheless very large,
which translates to weight and significant wind force on the structure when furling, combining to work
against going higher by reducing the tower weight. This shortcoming is supported by Figures 20 and 21.
The conclusion is that shrouds are impractical for utility grade wind turbines.
Returning to the objective to draw the air flow toward the center of the turbine by creating a higher
velocity lower pressure region in the center, the solution could be simply to locate essentially an orifice
plate as shown in View 6B. The geometry shown would create the desired air flow and present a
minimum area for wind resistance when furling.
Not illustrated, perhaps an even simpler approach is to remove the airfoil characteristic of the blade root
to allow the air to pass through with minimum effect on its velocity, which would accomplish the desired
lower pressure region to pull the captured air toward the center. The actual amount of airfoil to remove
requires study to determine if the possible gain in performance offsets the loss of chord area at the blade
root, where is maximum for the practice of the industry. However, combining the approach with the blade
chord modifications discussed above, IMPROVE BLADE PERFORMANCE BY ADOPTING AIRCRAFT
TECHNOLOGY, would have minimum effect on the energy captured.
Dwg. 6
6A 6B

20. TAKE
© Copyright 2019 Lawrence L Stewart All Rights Reserved
BLADE INDUCTED DRAFT PROPUL
Energy can be extracted from the centrifugal force
of the rotating blades to induct an air stream at the
hub, generating propulsive thrust at the tips.
Centrifugal Force- Blade rotation produces
centrifugal force working on the enclosed air mass
from the root to the tip. An intake is located at the
root and an exhaust nozzle at or close to the tip to
allow air movement. The momentum of the exiting
air mass provides thousands of pounds of thrust,
depending on Blade speed, to increase turbine
power.
Velocity Induced Draft- The rotating blade
produces a tangential velocity, creating a velocity
pressure that can be used to pull air from the root
intake. The resulting thrust can add 500 to 800
KW to an 8 MW machine, possibly more.
Thermal Induced Draft- Thermal energy may possib
present to heat the surface of the Blades.
optimum combination of material and geometry. The conducted heat in turn will be transmitted to th
internal air. The result is that the air pressure will increase by the ratio of the temperature
exhaust velocity of the air at the blade tip
propulsion. This incremental effect m
a heat absorption material to maximize the solar energy capture to apply the thermal stack draft effect.
The air intake is shown at the front of the blade root. A study of the actual f
better location for the intake. The moving air mass exhausts at the tip and can be
blade, contributing to the total energy available for power generation.
The angle of the exhaust nozzle will
(thrust) of the energized air stream to add to the electrical power generated.
A possible benefit of the ejection of air mass at the blade tips is amelioration of the vacuum condition that
is a cause of death of bats by ebullism, when they fly into the blade
spinning blades, or the rapid decrease in air pressure around the turbines can cause bleeding in their
lungs.”
(54)
WINDNOVATION™
E WIND POWER TO A HIGHER LEVEL
Lawrence L Stewart All Rights Reserved
PROPULSION
Energy can be extracted from the centrifugal force
rotating blades to induct an air stream at the
hub, generating propulsive thrust at the tips.
otation produces
on the enclosed air mass
An intake is located at the
exhaust nozzle at or close to the tip to
allow air movement. The momentum of the exiting
air mass provides thousands of pounds of thrust,
depending on Blade speed, to increase turbine
rotating blade
produces a tangential velocity, creating a velocity
pressure that can be used to pull air from the root
intake. The resulting thrust can add 500 to 800
KW to an 8 MW machine, possibly more.
Thermal energy may possibly be exploited. During daylight hours, solar energy is
Blades. This surface heat can be conducted to the interior by the
optimum combination of material and geometry. The conducted heat in turn will be transmitted to th
internal air. The result is that the air pressure will increase by the ratio of the temperature
blade tip, increasing the momentum and energy of the air
propulsion. This incremental effect may be small but since the blades require painting, it may as well use
a heat absorption material to maximize the solar energy capture to apply the thermal stack draft effect.
front of the blade root. A study of the actual flow dynamics may show a
moving air mass exhausts at the tip and can be vectored
, contributing to the total energy available for power generation.
will be optimized by modeling to generate the maximum momentum
to add to the electrical power generated.
A possible benefit of the ejection of air mass at the blade tips is amelioration of the vacuum condition that
f bats by ebullism, when they fly into the blade wake
. “
The flying animals run into
spinning blades, or the rapid decrease in air pressure around the turbines can cause bleeding in their
Page 20 of 25
ring daylight hours, solar energy is
This surface heat can be conducted to the interior by the
optimum combination of material and geometry. The conducted heat in turn will be transmitted to the
internal air. The result is that the air pressure will increase by the ratio of the temperatures to increase the
, increasing the momentum and energy of the air for radial
ay be small but since the blades require painting, it may as well use
a heat absorption material to maximize the solar energy capture to apply the thermal stack draft effect.
low dynamics may show a
vectored to propel the
by modeling to generate the maximum momentum
A possible benefit of the ejection of air mass at the blade tips is amelioration of the vacuum condition that
flying animals run into
spinning blades, or the rapid decrease in air pressure around the turbines can cause bleeding in their
Dwg. 7

21. TAKE
© Copyright 2019 Lawrence L Stewart All Rights Reserved
SUMMARY
Significant increase to Wind Turbine
wind farm engineering presented in this paper. The combined application of the innovations can make 16
MW and greater wind turbines attainable. The innovations allow the hub heights to be su
increased to capture the greater wind energy at higher elevations. The DC power collection system
improves overall efficiency and reduces both first cost and operating expenditures.
Qualitatively, a wind farm integrating all innovations as des
conventionally designed site for approximately
the proposed innovations combine to on
performance, for the same wind energy, 9
electrical and control systems would provide substantially reduced maintenance costs. Nacelle fires are
eliminated.
Many of the innovations presented are simply the recognition of effective engineered devices from the
past and updating those designs to improve the performance and costs of today's wind turbine. This
approach is validated by that taken
rotor area and tower height previously shown in Figure 5. The Vestas design calls to mind the 1930
concept of the German engineer, Hermann Honneff, "
Headed Windmill"
(55)
. The "Windmill" was designed to generate 30,000 HP, 22.4 MW!
In a recent paper
(56)
, it is reported “…
found 67 percent had experienced a significant decrease in wind power
Consequently, it is now more important
Challenges and novel concepts aside, both bigger and higher can be accomplished to T
Energy to the Next Level,
WINDNOVATION™
E WIND POWER TO A HIGHER LEVEL
Lawrence L Stewart All Rights Reserved
Significant increase to Wind Turbine capacity can be achieved by applying the innovative approaches to
wind farm engineering presented in this paper. The combined application of the innovations can make 16
MW and greater wind turbines attainable. The innovations allow the hub heights to be su
increased to capture the greater wind energy at higher elevations. The DC power collection system
improves overall efficiency and reduces both first cost and operating expenditures.
Qualitatively, a wind farm integrating all innovations as described would result in the same capacity as a
approximately half the cost. While Betz’s Law may not be exceeded, if
proposed innovations combine to only achieve 90% efficiency compared to the current 80%
r the same wind energy, 9 MW would be generated over the current 8 MW.
electrical and control systems would provide substantially reduced maintenance costs. Nacelle fires are
Many of the innovations presented are simply the recognition of effective engineered devices from the
past and updating those designs to improve the performance and costs of today's wind turbine. This
taken by Vestas to increase wind energy capture by increasing the swept
t previously shown in Figure 5. The Vestas design calls to mind the 1930
concept of the German engineer, Hermann Honneff, "Berlin's Wildly Fantastic 1,400-Foot
The "Windmill" was designed to generate 30,000 HP, 22.4 MW!
“… data from more than 1,000 weather stations worldwide and
found 67 percent had experienced a significant decrease in wind power potential since 1979.
it is now more important than ever to improve the energy capture of Wind Turbines.
Challenges and novel concepts aside, both bigger and higher can be accomplished to T
Energy to the Next Level, Windnovation™
Page 21 of 25
capacity can be achieved by applying the innovative approaches to
wind farm engineering presented in this paper. The combined application of the innovations can make 16
MW and greater wind turbines attainable. The innovations allow the hub heights to be substantially
increased to capture the greater wind energy at higher elevations. The DC power collection system
cribed would result in the same capacity as a
hile Betz’s Law may not be exceeded, if
urrent 80%
MW. Simpler
electrical and control systems would provide substantially reduced maintenance costs. Nacelle fires are
Many of the innovations presented are simply the recognition of effective engineered devices from the
past and updating those designs to improve the performance and costs of today's wind turbine. This
se wind energy capture by increasing the swept
t previously shown in Figure 5. The Vestas design calls to mind the 1930
Foot-High, Hydra-
data from more than 1,000 weather stations worldwide and
potential since 1979.”
ever to improve the energy capture of Wind Turbines.
Challenges and novel concepts aside, both bigger and higher can be accomplished to Take Wind

22. WINDNOVATION™
TAKE WIND POWER TO A HIGHER LEVEL
© Copyright 2019 Lawrence L Stewart All Rights Reserved Page 22 of 25
ENDNOTES
(1.) GLOBAL WIND REPORT ANNUAL MARKET UPDATE 2015, p. 22, http://www.gwec.net/wp-
content/uploads/vip/GWEC-Global-Wind-Report_2016.pdf
(2.) Today in Energy, June 6, 2016, EIA publishes construction cost information for electric power
generators Today in Energy, http://www.eia.gov/todayinenergy/detail.cfm?id=26532
(3.) Professor Randy Simmons, WHAT’S THE TRUE COST OF WIND POWER?, 4/1 1/1 5 ,
http://www.newsweek.com/whats-true-cost-wind-power-321480
(4.) Renewables Boom Expected Thanks to Tax Credit, Daniel Cusick, December 21, 2015,
http://www.scientificamerican.com/article/renewables-boom-expected-thanks-to-tax-credit/
(5.) Denmark says wind energy too expensive, Michael Batasch, May 13, 2016, The Daily Caller News
Foundation, https://www.cfact.org/2016/05/13/denmark-says-wind-energy-too-expensive/
(6.) Timothy Morris, "Let's keep reducing costs", AWEA" conference@awea.org, Email September 22,
2016
(7.) RENEWABLE ENERGY TECHNOLOGIES: COST ANALYSIS SERIES, Volume 1: Power Sector,
Issue 5/5, Wind Power, June 2012, p 6,
https://www.irena.org/documentdownloads/publications/re_technologies_cost_analysis-
wind_power.pdf
(8.) Megan Geuss, “Get ready for 24-30% reduction in cost of wind power by 2030”, Ars Technia,
11/29/2016, https://arstechnica.com/science/2016/11/experts-forecast-giant-11mw-offshore-wind-
turbines-by-2030/
(9.) Enabling Wind Power Nationwide, 2015, US Department of Energy, p 12,
http://www.energy.gov/sites/prod/files/2015/05/f22/Enabling-Wind-Power-
Nationwide_18MAY2015_FINAL.pdf
(10.) “Vestas shakes up wind power with a 12-blade turbine tower”, Lacy Cook, 07/06/2016,
http://inhabitat.com/vestas-shakes-up-wind-power-with-a-12-blade-turbine-tower/
(11.) Mark Crawford, “Wind Turbines Get Bigger and Smarter” July 2013, ASME.org
https://www.asme.org/engineering-topics/articles/renewable-energy/wind-turbines-get-bigger-
smarter
(12.) ibid.
(13.) Victoria Markovitz, “Sizing Up Wind Energy: Bigger Means Greener, Study Says”, National
Geographic News, published July 20, 2012
http://news.nationalgeographic.com/news/energy/2012/07/120720-bigger-wind-turbines-greener-
study-says/
(14.) 10 OF THE BIGGEST TURBINES, Windpower Monthly, Updated 3 September 201,
https://www.windpowermonthly.com/10-biggest-turbines
(15.) “Adwen and LM Wind Power Partner to Present the Longest Blade in the World”, 21 June 2016,
http://www.adwenoffshore.com/adwen-and-lm-wind-power-partner-to-present-the-longest-blade-in-
the-world-2/
(16.) Erin Ailworth, “The Race to Build A Wind Behemoth”, The Wall Street Journal, August 24, 2019,
https://www.wsj.com/articles/the-race-to-build-a-wind-behemoth-1535115601
(17.) Brian Clark Howard, “World’s Largest Wind Turbines: Is Bigger Always Better?”, National
Geographic,July 20, 2012, http://energyblog.nationalgeographic.com/2012/07/20/worlds-largest-
wind-turbines-is-bigger-always-better/
(18.) ibid.
(19.) Project Details for Thornton Bank phase 1, 4C Offshore Ltd,
http://www.4coffshore.com/windfarms/thornton-bank-phase-i-belgium-be01.html
(20.) Ibid.
(21.) Wind turbine, Wikipedia, the free encyclopedia, https://en.wikipedia.org/wiki/Wind_turbine
(22.) Vertical axis Wind Turbine, Wikipedia, the free encyclopedia,
https://en.wikipedia.org/wiki/Vertical_axis_wind_turbine
(23.) Dan Ancona and Jim McVeigh , Wind Turbine – Materials and Manufacturing Fact Sheet August
29, 2001, Princeton Energy Resources International, LLC,
http://www.perihq.com/documents/WindTurbine-MaterialsandManufacturing_FactSheet.pdf
(24.) RENEWABLE ENERGY TECHNOLOGIES: COST ANALYSIS SERIES, Volume 1: Power Sector,
Issue 5/5, Wind Power, June 2012, page 29, International Renewable Energy Agency
https://www.irena.org/documentdownloads/publications/re_technologies_cost_analysis-
wind_power.pdf
(25.) Ibid, page 43

23. WINDNOVATION™
TAKE WIND POWER TO A HIGHER LEVEL
© Copyright 2019 Lawrence L Stewart All Rights Reserved Page 23 of 25
(26.) Betz’s Law, Wikipedia, the free encyclopedia, https://en.wikipedia.org/wiki/Betz%27s_law
(27.) S Castegnaro, Aerodynamic Design of Low-Speed Axial-Flow Fans: A Historical Overview, p 4,
Istituto Nazionale di Fisica Nucleare (INFN), 35131 Padova, Italy; 21 June 2018,
http://www.mdpi.com/2411-9660/2/3/20.
(28.) Miroslav Petrov, Aerodynamics of Propellers and Wind Turbine Rotors, Lecture within the course,
Fluid Machinery (4A1629), Dept. of Energy Technology, Stockholm, Sweden. Slide No. 9, 2009
https://www.scribd.com/document/39281595/01-Propellers-WindTurbines-4A1629
(29.) "Wind Turbine Blade Design", Copyright TurbineGenerator.org, 2017,
http://turbinegenerator.org/wind/how-wind-turbine-works/blade-design/
(30.) Photo Collection, Dryden Flight Research Center, July 24, 1987
https://www.dfrc.nasa.gov/Gallery/Photo/X-29/HTML/EC87-0182-14.html
(31.) The X-29, Military Analysis Network, https://fas.org/man/dod-101/sys/ac/x-29.htm
(32.) Republic91 Thunderceptor, Wikipedia, https://en.wikipedia.org/wiki/Republic_XF-91_Thunderceptor
(33.) P47D Photograph,
http://p47.kitmaker.net/modules.php?op=modload&name=SquawkBox&file=index&req=viewtopic&t
opic_id=128328
(34.) 368th FG - The P-47 Thunderbolt - 368th Fighter Group, http://www.368thfightergroup.com/P-47-
R2800.html
(35.) Ibid, propeller variations for P47.
(36.) Scimitar propeller, Wikipedia, https://en.wikipedia.org/wiki/Scimitar_propeller
(37.) Grumman Northrop E-2 Hawkeye walk around and scimitar propellers 1 October 2012,
https://travelforaircraft.wordpress.com/2012/10/01/e-2-alpha-alpha-write/
(38.) Ibid, Betz’s Law
(39.) The wind energy fact sheet, Department of Environment, Climate Change and Water NSW 59–61
Goulburn Street. PO Box A290, Sydney South 1232, November 2010, p. 3.
http://www.environment.nsw.gov.au/resources/households/WindEnergyfactsheet.pdf
(40.) TRANSFORMERS FOR WIND TURBINE GENERATORS, By Subhas Sarkar, MSEE, PE,
SMIEEE; VP of Development, Virginia Transformer Corp., p. 1, http://www.vatransformer.com/wp-
content/uploads/transformers-for-wind-turbine-generators.pdf
(41.) John Diaz de Leon, P.E., “Renewable Energy – Connecting Wind Farms to the Grid”, IEEE PES –
Milwaukee Chapter Meeting, April, 2008, pp 14, 26
https://ewh.ieee.org/r4/milwaukee/pes/AMSCRene.pdf
(42.) Koby Attias, Shaul P. Ladany, Optimal Layout for Wind Turbine Farms, World Renewable Energy
Congress 2011 Sweden, http://www.ep.liu.se/ecp/057/vol15/014/ecp57vol15_014.pdf
(43.) TM. Rabiul Islam, Youguang Guo, Jianguo Zhu, "A review of offshore wind turbine nacelle:
Technical challenges, and research and development, Centre for Electrical Machines and Power
Electronics, University of Technology Sydney, P.O. Box 123, Broadway, Ultimo, New South Wales
2007, Australia, p 10,
https://opus.lib.uts.edu.au/bitstream/10453/33256/4/337_final%20accepted%20version.pdf
(44.) Colin Smith, "Fires are major cause of wind farm failure, according to new research", Imperial
College, London,17 July 2014 ,
http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_17-7-2014-8-
56-10
(45.) Sandip A Kale, Shivalingappa N Sapal, INNOVATIVE MULTI ROTOR WIND TURBINE DESIGNS,
Conference Paper · November 2012, DOI: 10.13140/2.1.3770.9768
https://www.researchgate.net/publication/267551965_INNOVATIVE_MULTI_ROTOR_WIND_TUR
BINE_DESIGNS
(46.) ibid Koby, p. 4155, https://www.google.com/patents/US8021100?dq=US+6877960+B1
(47.) Fan Performance Characteristics of Centrifugal Fans, FAN ENGINEERING FE-2400, ©2018 Twin
City Fan Companies, Ltd. https://www.tcf.com/wp-content/uploads/2018/06/Fan-Performance-
Characteristics-of-Centrifugal-Fans-FE-2400.pdf

24. WINDNOVATION™
TAKE WIND POWER TO A HIGHER LEVEL
© Copyright 2019 Lawrence L Stewart All Rights Reserved Page 24 of 25
(48.) Nakahama, Takafumi & Biswas, Debasish & Kawano, Koichiro & Ishibashi, Fuminori. (2006).
Improved Cooling Performance of Large Motors Using Fans. Energy Conversion, IEEE
Transactions on. 21. 324 - 331. 10.1109/TEC.2006.874245, p 325
https://scholar.google.com/scholar?q=Improved+Cooling+Performance+of+Large+Motors+Using+F
ans&hl=en&as_sdt=0&as_vis=1&oi=scholart
(49.) Rębielice Królewskie Wind Turbine, Atals Obscura, https://www.atlasobscura.com/places/rebielice-
krolewskie-wind-turbine
(50.) Karl Burkart, Japanese breakthrough will make wind power cheaper than nuclear, August 29, 2011,
https://www.mnn.com/green-tech/research-innovations/blogs/japanese-breakthrough-will-make-
wind-power-cheaper-than
(51.) Yuji Ohya and Takashi Karasudani, A Shrouded Wind Turbine Generating High Output Power with
Wind-lens Technology, Research Institute for Applied Mechanics, Kyushu University/ Kasuga 816-
8580, Japan, http://www.mdpi.com/1996-1073/3/4/634 , Abstract
(52.) ibid, Ohya, p 638
(53.) Walter M. Presz, Jr., Michael J. Werle, Wind Turbine With Mixers and Ejectors, United States
Patent No. US 8,021,100 B2 Sep 20, 2011,
https://www.google.com/patents/US8021100?dq=US+6877960+B1
(54.) Amy Mathews Amos, Bat Killings by Wind Energy Turbines Continue, Scientific American, June 7,
2016, p2, https://www.scientificamerican.com/article/bat-killings-by-wind-energy-turbines-continue/
(55.) John Metcalf, "Berlin's Wildly Fantastic 1,400-Foot-High, Hydra-Headed Windmill", Citylab.com ©
2018 The Atlantic Monthly Group, https://www.citylab.com/life/2013/08/berlins-wildly-fantastic-1400-
foot-high-hydra-headed-windmill/6530/
(56.) Jason Deign, “Chinese Researchers Claim Wind Resources Are Dwindling”, Greentech Media,
December 26, 2018, https://www.greentechmedia.com/articles/read/chinese-researchers-
claim-global-wind-resources-are-dwindling
NOTICE:
The following terms and slogans are the intellectial property of Lawrence L Stewart:
"Take Wind Energy To The Next Level”
“Take Wind Power to the Next Level"
“Taking Wind Energy to a Higher Level”
“Taking Wind Power to a Higher Level”
"Go Lighter, Go Higher”
"Windnovation”
“Windovation”
© Copyright 2016 Lawrence L Stewart All Rights Reserved
Addendum follows.

25. WINDNOVATION™
TAKE WIND POWER TO A HIGHER LEVEL
© Copyright 2019 Lawrence L Stewart All Rights Reserved Page 25 of 25
ADDENDUM
Provisional Patent Application filed with USPTO, May 14, 2019
NOVEL INNOVATIONS TO ACHIEVE HIGHER PERFORMANCE LEVELS FOR WIND
ENERGY EQUIPMENT AND SYSTEMS
Twenty One (21) Pages
Available on Request and Receipt of Executed Non-Disclosure Agreement
Contact: Lawrence L Stewart,
email: llstewart@gmx.com