Net zero energy article c

Perpetual Mobility and Sustainment on Water –
Net Zero Cost No Longer a Panacea
INTRO
With exception of the two Great Wars the cost of oil was a great deal until the 1956 Yon Kippur War and the
various Middle East wars that followed, with the OPEC cartel taking advantage of any and all political
instability in the Middle East to increase the cost of oil to meet their countries emerging social costs, which
has been seen as nothing short of holding the world’s economies hostage. Despite new sources of oil and the
emergence of Shale fracking some experts have forecasted that over the next decade demand will continue
to grow and oil prices could increase from approx. $100 per barrel to $200 representing a potential 100%
increase, demonstrating that no amount of improvement in vessels, vehicles and aircraft fossil fuel power
design improvements can counter the increase in oil pricing - leaving technology improvements going
backwards in relationship to fossil fuel prices – a situation that will remain until a disruptive technology can
be found. Could renewable energy be the solution?

Email: henning@hjaSolutions.com Internet: http://www.hjasolutions.com/, Blogs at http://www.hja-solutions.simplesite.com
Contacts: Henning Jacobsen (Montréal) (514) 214-4245 and (613) 961-0756 (Ottawa region)

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In September of 2009 Planet Solar became the first solar only powered vessel to set out to circumnavigate the
planet, to prove the feasibility of solar generated electricity as a source of power to move vessels in perpetuity eliminating fuel cost. In the period between 2009 and 2012 HJA Solutions studied Planet Solar’s performance in
order to identify improvements for a next generation vessel design for perpetual travel on water both for
commercial vessels, yachts and pleasure boats. During Planet Solar’s two year circumnavigation, we had a
dialogue with Dr. Pascal Goulpié, the science member of the Planet Solar team, who provided helpful

information on the technical aspect and the key issues of the circumnavigation. This information has greatly
aided our Study in order to identify and quantify new technology solutions that can be integrated into a next
generation Hybrid Solar Yacht. This article is built around excerpts of the Study’s findings.
Planet Solar’s around the world trip took place with frequent stops in many cities to promote solar power for
perpetual travel. The intermittent stops along the way have made it difficult to establish the true cruising
speed of Planet Solar. The most common speed during sunny days was 6 - 8 knots with short sprints up to 14
knots having been recorded and with 48 hours of battery capacity for mobility during times when the sun was
absent. By studying the Planet Solar log, it appears that the overall average underway speed throughout the
circumnavigation (40,000km/ 26,400 miles) was only 3-4 knots, an observation that may show that Planet
Solar is not yet economical for commercial transit based on the 2009 solar technology used. In addition, the
$20+ million price tag for the vessel shows that the concept has not yet reached economical viability, when
matched against the savings in fossil fuel cost. In fact Planet Solar’s PV technology has proven to have limited
potential for further development, but for the Study it has proven to be an excellent platform for benchmarking
future improvements in solar technology, battery/fuel cell developments, power management and vessel
design for development of a Next Generation vessel for perpetual travel at no cost.


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Magazines like Popular Science has since the 1950s frequently displayed solar, battery and wind solutions on
its pages, but with the low cost of oil not much happen until the first oil embargo in the 1973, but not until
the 1990s did we see renewable energy alternatives with practical value, but at very high prices and not until
the early 2000s did we see proliferation of solar and wind generated power accompanied by rapid cost
reduction making renewable technologies a real contender in several energy fields. Most developments
concern utility use, there have been some mobility experiments prior to Planet Solar, the most noteworthy
was the Sun21 a forty foot catamaran with a PV solar roof that crossed the Atlantic in 2007, but not until
2009 and the advent of Planet Solar did we see a full-fledged scientific expedition setting out to prove the
solar powered concept for ocean crossings.

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Past Power Generating Ideas

The TURANOR - Planet Solar


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The Planet Solar’s energy field output is achieved by use of solar panels produced by the California based
company SunPower, maker of the mono-crystalline silicon (c-Si) solar panels that in 2009 had efficiency of
23.4% DC for Cell, 19% DC for Module and 16% AC for System (module is used interchangeably with panel);
SunPower’s c-Si product was the highest efficiency PV production panel in the industry at the time. The PV
panel, in addition to providing Motive Power, also has to provide the onboard Hotel Load (the term for
sustainment onboard). The hotel load requirement varies with the size of vessels and the level of comfort
desired (ranging between 30kWh and 90kWh daily for vessels between 50-200 feet). The Planet Solar has
four electric motors that can achieve 127 horsepower for dash speed with 60kW of power from the two
30kW motors while 20kW from two sets of 10kW motors are used for normal cruising. The adjustment of

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Swiss engineer Raphael Domjan had long dreamt of circumnavigating the planet without using internal
combustion engines, his dream was realized during 566 days between 2009/9 and 2012/2 when he
circumnavigated the planet on a 102 feet long x 50 feet wide trimaran weighing 95tons with an upper solar
panel deck area of 5,059SF, plus extendable flaps and wings that when deployed added another 780SF making the total solar field 5,839SF. The flaps and wings appear to have been an after-thought to ensure
that more power could be available. The topside solar surfaces are covered with 38,000 solar cells with
93.5kW peak power(p) producing electricity during times of the day when solar power production occur (at
equator average 6 hours, in the temperate zone 5 hours – both conservative estimates).

power from one engine to another is used to steer the vessel which eliminates the need for a rudder (the
engine steering system suffered a breakdown in the Pacific Ocean in 2011 – and during the 2013 Upgrade a
rudder was added). Depending on the status of the battery charge, power is apportioned between electric
motors and the hotel load. By down selecting to the two lower power motors and deferring most onboard
power consumption – it will allow the vessel to extent its non-solar travel time until the sun emerges again.


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To enhance the effective use of power, the design chosen was that of a trimaran, due to the need to have a
large solar field on the top deck (5,839SF) above the living quarters for a crew of eight. To maximize the speed
of the vessel the nautical designer Craig Loomes from New Zealand created a design with two outrigger hulls
that was made wave-piecing to penetrate the surface to reduce resistance drag. To further improve efficiency
the designer also selected two five-bladed 6.7-foot diameter controllable pitch surface piercing carbon-fiber
propellers mounted at the aft end of the two outrigger pods - a drive system that has proven to be very
effective for this type of vessel. Each surface piercing propeller is driven by a pair of brushless permanent
magnet synchronous electric motors, which is a cross between AC induction and DC brushless motors. The
rotating parts of the motors are made from powerful permanent magnets with stationary field coils that work
like a three-phase AC motor. The DC from the batteries is inverted to AC at a frequency that varies according
to the combinations of motors and hotel load to reach the speed required. By alternating between the two
10kW motors and the two 30kW motors, the system converts the pulses of DC that are delivered to the field
coil at exactly the right time to produce the speed and torque required for the propellers to run at optimum
performance covering up to 125 miles (200km) in a day. To achieve the most efficient use of power from the
solar field, Planet Solar has developed a proprietary “Ten Step Computer Device”, that manages the flow of
power, together with a software program called the Maximum Power Tracker allowing for continuous
monitoring of the total system, dynamically adjusting consumption to achieve the best combination of
extracted power for the transit operation of the vessel while Planet Solar perpetually chases the sun around
the planet.

Lessons learned from Planet Solar
To voyage at reasonable and practical speeds over long distances for a future Planet Solar spin-off will need
some improvement. Theoretically, under perfect calm conditions Planet Solar can travel at 6-8 knots.
However, due to course changes, navigations errors, days without sun and break downs - the average speed of
Planet Solar for the journey was calculated to be only 3-4 knots.
The size of the Planet Solar energy field was initially considered adequate to deliver sun power production of
between 468kWh and 561kWh per day (Planet Solar best day of power production was in the Mediterranean
with 623kWh over a six hour period). During the 2009-2012 circumnavigation it became clear to the Planet
Solar team that power generation had been under-estimated, leaving the vessel short of adequate kWh, as
evidenced by the 2013 Planet Solar retrofit, in preparation for its new mission as a Science Platform to study
the Gulf Stream. The 2013 upgrade saw the top deck increase in size to become 5,515SF plus 780SF of flaps
and wings, totaling 6,295SF (resulting increase in the energy field size of 7.2%), which translates to an increase
in installed power from 93.5kWp to approximately 100kWp. This improvement was reported to have
increased the average speed from 3-4 knots to 5 knots, an increase that only marginally improved the Planet
Solar performance. This is possibly the best that can be achieved by Planet Solar due to physical size limitation
of the top deck. With c-Si products in 2012 having reached their maximum design cell efficiency of 25%,
compared with CPV today giving cell efficiency of 44.7%, module efficiency of 36.3%, adding 2-Axis tracking the
total efficiency before de-rate reaches 49% (de-rate for CPV DC is 11% versus 23% for PV AC panels), showing
CPV as superior technology and the more suitable candidate for motive power applications.
Solar Hybrid Yacht Integrated Energy System Architecture

Airborne
Generating
Wind Turbine
(not incl.)
Solar CPV
Modules

Taffrail Water
Generators Sailing yachts
Regeneration
Systems*
Electric/
Electric
Alternator
Motors
Motor*

Central
Energy
Mgmt.
System

Energy
Storage
System:
Batteries, or
Fuel Cells

Wind
Generator(s)

Energy
Preserving
Kite (SkySail)

Emergency/
Battery
Charging
Genset*

Electric/
Alternator
Motor*


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The HJA Solutions PowerPack architecture illustrates a range of elements addressed in the Study for the
Hybrid Solar Yacht’s renewable energy options that may make the vessel totally independent of fossil fuel.

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*Electric Motors, Alternator for Regeneration and Genset are all mature technologies (covered in separate Study)

The early use of PV modules are already usurped by CPV modules, making it possible to substantially reduce
the solar field and correspondingly the sizes of any vessel that uses the CPV technology, and allowing for more
energy for larger vessels as well as introducing opportunities to retrofit existing yachts.
Our challenge with the Study have been to find elements that can improve performance - with focus on solar
modules that are more efficient in generating electricity beyond the level of the 2009 c-Si modules used on
Planet Solar. A secondary objective was focused on finding improvements in energy storage - either batteries
or fuel cells. Although not finding a revolution in battery technology, the developments over the last five years
have resulted in batteries with 50% higher Ampere hours and 33.3% improvement in the battery depletion
rate. To accompany advances in energy generation and storage, new computer control systems and software
have emerged that will make integration of multiple energy sources vastly more capable compared with
currently marketed systems. Finally, we set out to find ways to get the price lower for all the elements, to
facilitate more reasonable offers, much of our success must be credited to the Planet Solar that has made it
possible to measure and compare our findings. The following sections will describe each of the elements:


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The 2013 National Renewable Energy Laboratory (NREL) chart above indicates that Sun Power’s 2009 cell
efficiency lies in the middle of the chart, the new Concentrated Photovoltaic (CPV) developments lie above
the line, most reflects prototype cells not yet in production, but some CPVs have become manufacturing
available, our choice was the current world record holder CPV with 44.7% cell efficiency. NREL forecasts
addition cell efficiency to reach 50% by 2015, which provides over double the efficiency of the SunPower

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Future Hybrid Solar Yacht – Power Generation

2009 c-Si panels, it will allow for further reduction in the solar field of over 50% and a corresponding
reduction in vessel size, or alternatively double the energy generation for a vessel of equivalent size to
Planet Solar – which greatly will improve speed. The application of CPV is no longer an issue of cell output,
but rather an engineering challenge, one that can more easily be solved than developing new solar power
cells with higher output. By adding an off-the-shelf 2-Axis hydraulic tracker, it will give a further increase in
electric output (1-Axis East-to-West tracking increases efficiency by approx. 20%, a 2-Axis tracker increases
power by adding vertical tracking for a total 30% improvement (see Index 3: Efficiency Table).

The CPV 2-Axis solar power system
Bank of Embedded CPV 2 x 5 modules 12.5’ x 12.5’

Engineering Unit - 2-Axis Prototype of CPV
Model


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The HJA Solutions’ Study aimed to validate the CPV demonstrator with the module hydraulic tracking – making
certain that the engineering and power generation targets could be met. The work was conducted on a scale
model of a technology demonstrator. The findings showed that the conceptual Hybrid Solar Yacht will have
sufficient power output measured against the calculated consumption. The reduction in size and weight will
have a cascading effect of all aspects of consumption – far beyond the impact of linear element reduction.

The proposed 50 foot Hybrid Solar Yacht design has been calculated to require only two banks of five
12.5’x12.5’ modules for approximately 1,563SF (73.2% smaller energy field than Planet Solar), along with
other energy saving concepts that when added will meet the total power requirements. The CPV modules and
the 2-Axis tracking unit will be located in the top deck at a depth of 24 inches with the CPV system hidden
from view - deep enough to accommodate the unimpeded movement of the hydraulic tracking device – each
bank will appear flushed with the top deck or roof structure with each bank covered by a clear optical quality
glass to prevent water spray and humidity intrusion.
The Hybrid Solar Yacht’s CPV 2-Axis sun tracking mechanism will create an equivalent energy field of approx.
50kWp, sufficient along with a wind turbine used as auxiliary power unit to generate the required energy
output for perpetual travel (see separate wind turbine section – below). Also, facilitating the Hybrid Solar
Yacht’s power production is a substantial increase in use of DC direct current, resulting in less conversion from
DC to AC for most onboard uses - which otherwise will carry a loss between cell and system of 23%. By using
new DC engines and DC hotel load (11% de-rate) wherever possible for appliances like LED Lighting, Air
Conditioning, Refrigerator, Induction Cooker and LED TV – it will alleviates much of the need for conversion to
AC - enhancing available power by 8-10% which benefits the energy budget, for all but a few devices requiring
AC current only (estimated daily use of 80% DC and 20% AC). The use of DC wherever possible will ensure that
higher speeds can be obtained, and/or facilitate increased charging of batteries for more available power
reserves, and eliminating periods when power for the hotel load has to be conserved to the detriment of
comfortable onboard living.

New Solar Cell Tracking Option


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In our continuous search for the most advanced solutions for the PowerPack design we witnessed a
demonstration by the Cambridge University Eco Racing (CUER) team during development of their Electric
Vehicle (EV) which successfully demonstrated an electronic system and software controlling tracking; it
performs the tracking of each CPV module using GPS logarithmic calculations adjusting the tracking by
directional movements of the angle to the sun. Further research seeks to have modules automatically align
with the hottest spot at 90 degrees to the sun at all times -focusing sunlight onto CPV cells with 256 times
concentration (newer systems use up to 1000x). The CPV systems compared with PV panels generates more
heat, but ventilation fans - using very little energy (0.6W each) - has proven that the temperature can be kept
under control as well as the potential to extract heat to a heat sink for heating and cooling.

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The CPV system already have double the efficiency of the 2009 SunPower c-Si PV panels, but in order to
achieve maximum power from the CPV propulsion, the modules need to track the sun across the sky
throughout the 5-6 hours of sunshine production. The current technology is based on hydraulic tracking
equipment which is commercial off-the-shelf (COTS) and it has proven to work reliably on utility projects
throughout the world. The demonstrator described above uses such hydraulic tracking equipment but it is
bulkier than it needs to be (design for static utility operations) – though the prototype hydraulic tracking
device used in the demonstrator was reduced in size substantially – it is still not ideal. The hydraulic
tracking equipment onboard a vessel will be subject to constant movement (pitch and yawl), which begs
the question about the level of reliability of hydraulic trackers throughout passages of long duration.

The CUER developed CPV and tracking system had to be very small, since it had to fit in an EV with space of
only 2.85m2 (30ft2) making up the total CPV solar cell unit.

Complet CPV unit with 12 cells, and testing lenses showing light spots with 256 times concentration of sunlight

The CUER design team built their EV to compete in the Australian World Solar Rally that runs over 3,000
km each year from Darwin to Adelaide. In 2013 the CUER design was the only EV that used CPV cells and
tracking, out of the 48 EV designs that were entered in the ralley. The CPV system used in the CUER EV is
similar to that described for the Hybrid Solar Yacht, and the tracking on rough roads with surface vibration
was successful which bodes well for use on vessels plying the sea and lakes.


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The software developed to create CUER’s EV design can also be used to control the optimum tracking
function from a remote location like the bridge of the yacht. The need to prove that the CPV system
operation and the tracking movement will perform as intended, has created an energy forecasting model that
will allow the detailed calculations required to determine the total energy requirements for any size solar
field for any vessel design in order to optimizing the energy production.

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The CUER validation model for CPV Solar efficiency

Energy Storage Options
The accelerated developments in Energy Storage are focused on eight technologies: batteries, hydrogen fuel
cell, compressed air, flywheels, super conducting magnetic energy, thermal energy, ultra-capacitors,
isentropic storages – these technologies will compete head-to-head, but size and weight will determine
specific systems suitability. In the marine industry today there is little tangible progress in production of
energy systems except for Lithium Ion (Li-ion) batteries, which are showing substantial benefits over the
second choice Nickel-metal-hydride (NiMH) batteries. The drawback with Li-ion so far has been overheating
particularly onboard aircraft, and in cars, but no overheating has been reported in the marine environment.
The second drawback is the price, due to incremental improvements in density, the Li-ion batteries has seen
increases in price - making it the greatest stumbling block today. Recently, the Li-ion Manufacturers
Organization in its “Forecast 2013-2020” stated that cell level prices will decrease to half by 2020, attributed
to higher than expected demands from the Electric Vehicle Industry.

Energy Density
Wh/Kg
10000

High-pressure
Hydrogen (35 Mpa)

Gasoline

CNG
20 Mpa)

Diesel

Bio-diesel
Ethanol

Liquid fuels

(Wh/Kg)

Gaseous fuels

Specific Energy

1000
Hydrogen
absorbing
Alloy (2wt%)

Batteries

ThB 500Wh/Kg.
Battery Efficiency Development 2000 - 2020 (Wh/Kg)
500
200
100
50

LMB 200Wh/Kg

Lithium-ion
100

Nickel metal hydride

Lead Acid

Lead
0

1000

2000

3000

4000

5000

Li-ion 200-2020
6000

7000

Liquid Metal
8000

ThB (Notional)
9000

10000

Volumetric Energy Density (Wh/L)

The current battery research indicates that some efforts are showing signs of progress. The Liquid Metal
Battery (LMB) developed at MIT is projected to have a specific density of 250Wh/kg, nearly double that of
most Li-ion batteries (75-150Wh/kg). Also attracting much attention is the rumored Thorium Plasma
Battery (TPB) which no-one has seen and it appears to be cloaked in secrecy - involving a U.S. Government
"gag order" and stories of several disappearing scientists. A patent search revealed the existance of TPB, but
access to information has been blocked. The TPB is rumored to have specific density of more than 500Wh/kg
– it would be revolutionary, if it is real. There are also in development some small nuclear reactors that are
referred to as nuclear batteries and Aneutronic fusion machines which are planned for prototypes by 2020.

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Source: Toyota

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LMB: Liquid Metal Battery –still under investigation
ThB: Thorium (Plasma) Battery - still under investigation

The Fuel Cell storage as an alternative to batteries has seen substantial development over the last decade. In
2007 the U.S. Congress directed the U.S. Navy to use integrated electric power systems, based on fuel cells
or nuclear reactors as alternative power sources to ensure the lowest possible operational cost in the future
(FY 2007 Defense Authorization Act). To that end the Office of Naval Research (ONR) was established to
research the Next Generation Integrated Power System (NGIPS) with focus on the use of electric power and
fuel cells storage for naval ships, with a promise of reducing fossil fuel consumption by 35-40%. During the
last decade vast sums have been spent by the USN for its development of DDG-1000 Zumwalt, an all electric
destroyer launched in Q4 2012, using hydrogen fuel cells for energy storage. All indications are that the use
of fuel cells could in the future replace marine batteries, but for the foreseeable future the civilian use of
fuel cells are seen to be too exotic and expensive – but rapid growth in production of fuel cells, can soon
make it possible to change batteries for more efficient fuel cells (see attached “Naval Power Source” article).
However, Planet Solar did demonstrate that the Li-ion batteries did the job, and that the shortfall in
performance was identified as lack of solar power generation - not as an energy storage deficiency, though
the battery banks were very large and heavy and as such these are not a desirable solution. Li-ion batteries
for vessels of around 50 feet in length, using CPV 2-Axis solar field power, will prove to be considerably more
efficiently in meeting the recharge rate and providing increase in the battery depletion capacity.
The Planet Solar’s power field routes excess power to its Li-ion batteries, consisting of 688 Li-ion cells
making-up 3 battery packs placed in the outrigger pods, these batteries have a combined weight of 11ton
with a capacity of approx. 2,900Ah; which has demonstrated that the batteries can drive the vessel for more
than 48 hours while awaiting the sun to appear. During short periods when Planet Solar recorded 14 knots
dash speed under favorable sun conditions - there was no excess power generated towards charging the
batteries, but at an average speed of 6-8 knots there are some recharging, but recharging is slow and
discharge capacity is limited, and not comparable to the more efficient LiFePO4 Lithium Phosphate battery
system available today (Lithium Phosphate battery is one of the many chemical variants of Li-ion battery).


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The Marine energy storage system developments have seen noticeable improvement over the last couple of
years, as demonstrated by a St Francis 50 foot sailing catamaran (similar challenge to the Hybrid Solar
Yacht). When Paul Burgessl, the owner of the Suliere decided to upgrade from his 2009 AGM power system,
he selected LiFePO4 batteries which has proven to give his yacht a 50% increase in available ampere hours,
as well as a greatly simplified and stabilized electrical system.

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One can calculate that a 2009 half scale Planet Solar would need approx. 1,450 Ah (344 cells) to perform
proportional storage with Li-ion batteries at a weight of 5.5tons. Using the current LiFePO4 Lithium
Phosphate battery system on the Hybrid Solar Yacht - it will have equal capacity with a battery bank
weighing only 2.3tons. The LiFePO4 Lithium Phosphate batteries along with reduction in volume and weight,
are more efficient and have 6 times faster charge-up time than the older Li-ion batteries as well as a
depletion capacity of 70% instead of the 2009 Li-ion at 40% - it suggests vast savings in the energy storage
requirements, improved discharge performance and a substantial reduction in price.

Hybrid Solar Yacht using the new LiFePO4 batteries vs. AGM - comparisons:
Type
Battery
AGM
LiFePO4

Units Unit Ah
6
4

110
400

System Ah
660
1600

Discharge
%
40
70

Net Ah
Efficiency
396
560

Approx Unit
USD
3,000E x 6
6,500 x 4

Relative
benefits
71%
99+%

Weight
100%
50%

Additional power augmentation
The Hybrid Solar Yacht is so called because the yacht concept proposes additional systems for power
generation, with combined output that will generate additional power to increase the cruising speed and
improve charging of the yacht’s batteries to offset the drain on the energy Budget:

The development of small
wind turbines has experienced rapid change. New wind turbines can augment power production on overcast
days, from wind at sea that is nearly always in evidence. The addition of wind generated power will ensure
extended mobility and guarantee the full use of the most critical equipment and appliances. This simple
solution will generate electricity for any emergency and ensure adequate hotel load at all times.


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Two wind turbines depending on wind speed have the potential of generating 20-40kWh/d (24 hour period);
new ducted wind turbines show improvements to 26-52kWh/d. The power available from the wind varies with
the cube of the wind speed. If the wind speed doubles, the power of the wind increases 8 times. One of the
effects of the cube rule is that a location that has an average wind speed compared with one that has wide
swings from low to high velocity, will have more energy potential over a location with a steady average wind
speed. This is because the occasional gusts pack a lot of power in a short period of time. Of course, it is
important that the occasional gust come often enough to keep up with the Hybrid Solar Yacht’s power needs.
The new small wind generators can be stored flushed in the deck and be flipped up to start operation. In 2013
Krishan Meetoo developed a mathematical model for calculating air flow improvement, by the shape of the
shroud and the fan blades in small wind turbines that show a documented improvement of 30% in output
compared with existing wind turbines. The new wind turbines are small, only 6 feet in diameter and weighting
only 240 lbs, the magnet field is fixed in the rim which results in negligible vibrations due to the elimination of
the gearbox and generator; the blades are shrouded, and create very little noise, only 35db at 10 feet. The
maximum efficiency of wind turbines are 59%, the traditional land-based small wind turbines with gears and
generators only achieve 33% efficiency, the new gearless ducted small generators have performance on open
water with wind speed 10-20mph (16-32kmh) at near 50% efficiency.

Alternate Power Augmentation - long distance transits

An additional power generation option for vessels up to 10,000 ton is developed by SkySail using a super
large towing kite that can be deployed on ocean crossing routes with favorable wind condition in sizes up to
160m2 (1,722SF), at a total system weight of 900kg and it is remotely operated from the ship’s bridge. The
SkySail system is intended to facilitate conservation of fossil fuel for vessels traveling at 8-10 knots during
long transits - in wind of 25 knots (10.8m/s) with the Kite at an altitude 100 - 300 meter (328 – 984 feet). The
fuel saving for a 10,000 ton freighter at today’s bunker oil price is approximately $1,800 per 24hr transit day.


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The launch mechanism uses a short telescopic mast for hoisting the 40m2 Kite (it takes 5 minutes to launch
and 10 minutes to retrieve and pack). The operation of the equipment when aloft is completely automatic,
requiring only human intervention for packing and storing the Towing Kite. The system is relatively
inexpensive, with stats indicating 35% average fuel savings (on certain routes the fuel savings have proven to
reach 50% per day). For the Hybrid Solar Yacht the SkySail will place less demand on the electric consumption
for motive power and also preserve the power of the batteries for uses other than motive power - the SkySail
Kite is particularly cost effective for longer transits. The Economics of the SkySail system shows an 18 to 24
month repayment schedule by continuous use and thereafter a life-long relief from energy cost.

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The 50 foot Hybrid Solar Yacht can use a 40m2 (431SF) SkySail systems with the kite
weighing only 9kg. The kite is launched out a forecastle bench with a small hydraulic mast deployed and
controlled from the bridge. The operation of the kite has a proven control system fitted with electronics that
measures air speed and wind direction aloft allowing for adjustments during the operation, this size kite has
energy saving equivalent to 400kW. When deployed at 100 to 200 meter (328 to 656 feet) it will take
advantage of the stronger and steadier airflow – 25% stronger than on the surface. The SkySail’s control
system will steer the airfoil over a 60+/- degrees arc pulling a yacht forward. The kite generates five times
more power per square meter than a conventional sail.

Hybrid Solar Yacht Cost Data
The size of the energy field is the over-riding impact on the vessel design, size and cost. Over the last three
years PV modules has seen a dramatic price reduction from $3.50Wp to $1.00Wp (71.4% reduction), the best
c-Si cell performance in 2012 reached 25% efficiency (up only 1.6% from 2009 23.4% cell efficiency) and it is
now recognized that c-Si PV cells have reached their performance improvement limit for mobility.
A CPV alternative to conventional c-Si PV has emerged as a much more efficient solution to generate higher
levels of power. The CPV products are available in 2013 at $2.95Wp, (66.1% more expensive than 2009 PV,
panels, but with cell output of 44.7% nearly double the efficiency of c-Si cells. By adding 30% increase for 2Axis hydraulic sun tracking, the final CPV module (down on level from cell) achieves a level of improvement of
47.2% before de-rate, but still more than double the efficiency of the best 2009 c-Si panels with a module
level efficiency of only 18%. The up to 70% smaller CPV vessel demonstrates the limiting factor of the current
Planet Solar c-Si panels and clearly shows the lower cost of the energy field. The prices listed above are for
products at Cell level costs, without consideration to engineering of power systems and installation.
The 50 foot Hybrid Solar Yacht can operate with a 1,563SF solar energy field or 1,200SF with solar field and
wind turbine augmentation, despite the 66.1% increase in price, it still makes the CPV less expensive than the
PV, since the energy field’s physical size will be so much smaller. Three years of solar field power
developments has now made it possible to consider reasonable perpetual mobility and sustainment on water
at zero cost for use in vessels from 50 to 200 feet. By adding wind turbine(s) to the design - it ensures
continuous travel even when the sun is absent and after the batteries have been drained to their 70%
depletion limit.


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The systems that will provide freedom from fossil fuel for many types of vessel is the CPV 2-Axis solar energy
field which will make it possible for vessels to become totally independent of fossil fuel. As technology
evolves in the future new cells at 50% efficiency and improved tracking forecasted to increase from 30% to
35% over the next couple of years will meet the challenge of perpetual mobility without fossil fuel. In the
event Li-ion batteries could soon be replaced by a stack of fuel cells for improved energy storage, it will
ensure improved availability of stored solar energy. By augmenting vessels with small wind generator(s) it will
provide augmentation for emergency performance and/or off-set the need for solar to provide Hotel Load.
Should routing be suitable such as ocean passages, a SkySail kite will substantially reduce the solar mobility
consumption by an average of 35% – thus preserving battery power. New computerized management system
will integrate all energy collection into a complete overarching system that will have a cascading downward
impact on the availability of sufficient power for all mobility and sustainment needs. Modern software exists
to manage the distribution of energy more efficiently. For the foreseeable future, the Hybrid Solar Yacht and
vessels up to 200 feet will be totally independent of fossil fuel in perpetuity. It seems that there are now
sufficient theoretical proof that both fuel saving and capital cost reduction can result in a practical solution
that will benefit its owners and at the same time lessen impact on the environment.

14

Conclusion

kWh Output vs. SF Energy Field plus Wind/SkySail for 24h travel
6500
6000
SF

5500

8kn

5000

10kn

4500

12kn

4000
3500
3000
2500
2000

1500
1200

kWh

12 Kn
-123

-208

kW/24h
8kn
10kn
12kn

-531

-624

-934

-1,037

20
-374
-761

162

-218
-589

305
-61
-417

447

95
-245

590
252
-73

732

408
99

875
565
272

1,302
1,034
788

1,159
878
616

1,017
721
444

Planet Solar 2009 - 3-4kn
PV high speed unatainable

6kn is always in positive territory, 8kn require 1,750SF power field, 10kn require 3,300SF power field, 12kn require 4,500SF power field

kWh Output vs. SF Energy Field plus Wind/SkySail for 12h travel

6500

6000
5500
SF
5000
HSY 12kn
4500

4000
3500
3000
2500

1,688

2000
1,172
1500
827

1200
311

483

1,344

1,516

999

655

139

12 Kn
-137

-34

Planet Solar 2009 - 3-4kn

6kn, 8kn and 10kn are always in positive territory, 12kn requires minimum 1,750SF power field


Page

15

PV high speed unatainable

Post Script – Next Step a Prototype Demonstrator
The next phase of the development will be to build a prototype vessel; the plan is to acquire a used 50 foot
catamaran with an existing back-up generator and most of the navigation, electronic and electric equipment
onboard, this will help keep cost down. Based on the suppliers’ Rough Order Magnitude (ROM) estimates for
the CPV Solar System and the electronic tracking/control/modeling equipment, the LiFePO 4 battery system,
one or two wind turbines, two sets of DC brushless permanent magnet synchronous electric motors, the
energy splitter and DC/AC electric control equipment, DC/AC inverter as well as installations and wiring
including electronic modelling tools - will be possible within a budget of $1.2million. All the elements have
been developed by different companies, but these subsystems have never been integrated to form a
PowerPack unit. It is expected that in the future a production variant of the 50 foot basic version catamaran
should be priced at $600,000 - not much beyond the fossil fuel powered catamarans today. The Hybrid Solar
Yacht’s break-even takes place within 438 days of continuous travel (14½ months), not accounting for the
fact that fossil fuel could go to $8 per gallon over the next decade, in which case break even is 219 days of
continuous travel (7+months or 5,000 hours of use).
Note: HJA Solutions will be consulting on PowerPack unit designs described in this article to individual owners
for retrofits and to boat yards interested in improving on their current un-integrated or partial solar power
generation solutions installed to reduce fossil fuel use. See the Internet site listed in the footer for more
information. HJA Solution is preparing an invitation for Crowd Funding of a 50 foot Demonstrator Hybrid Solar
Yacht, with a flexible top deck to attach CPV modules that can validate all existing and future technology for
use in vessels from 50 to 200 feet.

Hybrid Solar Power/Diesel Electric Yacht
Diesel
Fuel
Tank
GenSet

Batteries
LithiumIon

DC Motors

1 or2 Electric
Motors

1 or 2 Propeller
Drives

Plug-in Shore Power
Solar
Field*

Charge
Control
Unit

DC Dist.
Appliances

DC fridge, stove, TV, and LED lighting

AC
Inverter

All Other Appliances

* Red Denotes Packaged Power System, Blue Existing or standard generator


Page

16

Simplest Solution, providing partial solar electric power for vessels 50-100’ Total Solar Energy
Approx. 3,000 SF PV, or 1,500SF CPV . Li ion batteries can in the future be exchanged for a
Hydrogen Fuel Tank and a Fuel Cell Stack .
Required Power Pack system and equipment:
1) Diesel Gen-set – PV energy field too large for yachts below 100’, PV efficiency not adequate,
2) CPV Solar energy field/power control, will provide marginal total energy for yachts of 50’,
3) Lithium Ion Batteries 144 3V cells, adequate but expensive, replaceable by fuel cell stack,
4) Two (or one) DC Motors, DC use for mobility/key appliances increase energy by approx. 17%
5) DC Appliances: fridge, stove, TV, and LED lighting (LCC for continuous use accounts for 75%),
6) New systems Installations and wiring.

Hybrid Solar/Wind Turbine Power Yacht
Diesel
Fuel
Tank
Batteries
LithiumIon

GenSet

DC Motors

1 or2 Electric
Motors

1 or 2 Propeller
Drives

Plug-in Shore Power
Split/Charge
Control
Unit

Solar
Field*

Wind
Turbine(s)
1 or 2

DC
Appliances

DC fridge, stove, TV, and LED lighting

AC
Inverter

All Other Appliances

* Red Denotes Packaged Power System, Blue Existing or standard generator

Future Solution, provides total solar electric power, and higher speed than current solar power
systems - could retain Gen-set for emergences. Total Solar energy requires 2,500 SF PV,
or 1,000 SF CPV . Wind Turbine provides emergency charging of batteries for unbroken travel.
Required Solar and Wind Power Pack system and equipment:
1) Diesel Gen-set,,
2) CPV Solar energy field and power control suitable size 50 – 200 feet yachts ,
3) Lithium Ion Batteries 144 3V cells,
4) Two (or one) brushless DC Motors,
5) Selection of DC Appliances
6) New Installations and wiring

Index 3: Cell – Module – System Table:

Module
(DC)

System
(AC)

T racking
1-Axis

T racking
2-Axis

SP PV -2009
SP PV -2011
A CPV - 2009
A CPV - 2010
A CPV - 2011
A CPV - 2012 DC/AC
A CPV - 2012 DC/AC +

23.4%
25.0%
36.0%
39.0%
40.0%
44.7%
44.7%

19.0%
20.3%
29.2%
31.7%
32.5%
36.3%
36.3%

16.0%
19.3%
27.7%
30.0%
30.8%
34.4%
34.4%

~
~

33.3%
36.0%
37.0%
43.6%
43.6%

~
~

36.0%
39.0%
40.0%
47.2%
49.0%

NREL- 2015 Projected
NREL - 2015 DC/AC+

50.0%
50.0%

40.6%
40.6%

38.5%
38.5%

46.2%
48.7%

50.1%
54.8%

References throughout the article to DC, AC, 1-Axis and 2-Axis tracking are based on the assumptions in the
table above. The highlighted boxes reflect the baselines for calculating DC or AC. DC can be used without
inverters hence giving a higher energy output. Built on the use of 80% DC and 20% AC the chart indicates
improvement between 2009 and 2013 by 31.2%, which is equal to the amount of kWh per year during
continuous travel to offset the onboard use of Hotel Load - releasing completely the power generation for
mobility. The forecasted improvements between 2009 and 2015 with the best CPV and 2-Axis tracking shows
an efficiency improvement of 38.8% (the + indicates projected increase in tracking performance from 30% to
35%. These findings bode well for the successful performance of vessels between 50 to 200 feet to achieve
complete independence from fossil fuels.

17

Cell
(DC)

Page

Type

Net zero energy article c

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