- Energy efficiency technologies can significantly reduce energy usage and costs for ships through innovations like hull design improvements, efficient propulsion systems, waste heat recovery, and alternative fuels. - Examples of promising technologies include air lubrication systems to reduce hull resistance, optimized propeller and rudder designs, waste heat recovery systems, and use of sails or kites to capture wind power. - Adopting a portfolio of these technologies through concepts like the low loss power distribution system, combined diesel-electric propulsion, or efficient auxiliary systems can lower energy usage on ships by 5-30% depending on the vessel type and operational profile.

1. Technology Innovations
for Cost-effective Energy
Efficiency Measures
Image Credit: wind-ship.org
Mohd. Hanif Dewan, IEng, IMarEng, MIMarEST (UK), MRINA(UK),
Maritime Lecturer and Assistant Consultant (IMO)

2. Simple Concept of Energy Efficiency:
Energy efficiency is a very broad term referring to the
many different ways we can get the same amount of work
(light, heat, motion, etc.) done with less energy. It covers
efficient cars on the roads, efficient ships in the waters,
improved industrial practices, better building insulation and
a host of other technologies. Since saving energy and
saving money often amount to the same thing, energy
efficiency is highly profitable and great contributor for the
climate change issue. Energy efficiency often has multiple
positive effects.
For a simple example, an energy saving light gives more
amount of light by consuming less amount of electrical
energy than a traditional lightbulbs.

3. Source: afdf.com
• Compared to traditional incandescents,
energy-efficient lightbulbs such as
halogen incandescents, compact
fluorescent lamps (CFLs) and light
emitting diodes (LEDs) have the
following advantages:
 Typically use about 25%-80% less
energy than traditional incandescents,
thus saving the money,
 Can last 3 to 25 times longer, thus
saving the money,
 3 to 5 times less energy consumption
and Thus saving more energy. So, less
fuel consumption and less emissions
from power plants.

4. Energy Efficiency Measures
• The amendments to MARPOL Annex VI Regulations for the
prevention of air pollution from ships, add a new chapter 4 to
Annex VI on Regulations on energy efficiency for ships to make
mandatory the Energy Efficiency Design Index (EEDI) for new
ships, and the Shipboard Energy Efficiency Management Plan
(SEEMP) for all ships (resolution MEPC.203(62)). Other
amendments add new definitions and requirements for survey
and certification, including the format for the new International
Energy Efficiency Certificate (IEEC).
• In 2011, IMO adopted mandatory technical and operational
energy efficiency measures which are expected to significantly
reduce the amount of CO2 emissions from international
shipping. These mandatory​ measures (EEDI/SEEMP) entered
into force on 1 January 2013.

5. Cost-effectiveness of energy-efficiency measures
Some examples of technology innovations expected to be adopted
through effective EEDI and SEEMP implementation include speed
reduction, weather routing, use of auxiliary power and a focus on
aerodynamics (see Figure 1).

6. Cost Effective Technology Innovations
• Technologies which are available to significantly
improve energy efficiency in the short, medium
and long-term include:
1. Ship capacity enhancement
 Larger ships
 Purposely designed ships for specific routes/cargo mixers
 Multi-purpose ships (combination carriers) to avoid ballast
(empty) legs
 Use of light weight construction materials;
 Zero or minimum ballast configurations;

7. 2. Hull and propeller Designs
Hull optimisation for less resistance and
improved sea margins.
Advanced underwater hull coatings and
monitoring.
More hydro-dynamically efficient aft-ship,
propeller and rudder arrangements.
Reduced air drag through improved
aerodynamics of hull and superstructure.
Hull air lubrication systems.

8. 4. Engines, waste heat recovery and
propulsion system
 More efficient main and auxiliary engines (de-
rating, electronic control, longstroke,variable
geometry turbocharger, etc.);
 Waste heat recovery and ship‘s thermal energy
integration;
 Fuel cell and hybrid electric technologies

9. 4. Alternative fuels
LNG
Nuclear
5. Alternative sources of energy
Solar panels
Wind power such as kites, sails and
flettner rotors

10. The list of technologies that is expected to be used for reducing future ship‘s EEDI:
Source: MEPC 63, IMO.

11. Large Ship’s Design
• A larger ship will in most cases offer greater transport
efficiency due to efficiency of scale•. A larger ship can
transport more cargo at the same speed with less power
per cargo unit. Limitations may be met in port handling.
Source: Wärtsilä
• Regression analysis of recently built ships show that a
10% larger ship will give about 4-5% higher transport
efficiency.

12. Minimum Ballast Configurations
• Minimising the use of ballast results in lighter displacement and thus
lower resistance. The resistance is more or less directly proportional to
the displacement of the vessel. However there must be enough ballast
to immerse the propeller in the water, and provide sufficient stability
(safety) and acceptable sea keeping behaviour (slamming).
Source: Wärtsilä
• Removing 3000 tons of permanent ballast from a PCTC and increasing
the beam by 0.25 metres to achieve the same stability will reduce the
propulsion power demand by 8.5%.

13. Lightweight Structures
• The use of lightweight structures can reduce the ship weight.
 In structures that do not contribute to ship global strength, the use of
aluminium or some other lightweight material may be an attractive
solution.
 The weight of the steel structure can also be reduced. In a
conventional ship, the steel weight can be lowered by 5-20%,
depending on the amount of high tensile steel already in use.
•
• A 20% reduction in steel weight will give a reduction of ~9% in propulsion
power requirements. However, a 5% saving is more realistic, since high
tensile steel has already been used to some extent in many cases.

14. Optimum Block Coefficient
• Finding the optimum length and hull fullness ratio (block coefficient, Cb) has
a big impact on ship resistance.
• A high L/B ratio means that the ship will have smooth lines and low wave
making resistance. On the other hand, increasing the length means a larger
wetted surface area, which can have a negative effect on total resistance.
• A too high block coefficient (Cb) makes the hull lines too blunt and leads to
increased resistance.
• Adding 10-15% extra length to a typical product tanker can reduce the
power demand by more than 10%.

15. Interceptor Trim Planes
• The Interceptor is a metal plate that is fitted vertically to the transom of a
ship, covering most of the breadth of the transom. This plate bends the flow
over the aft-body of the ship downwards, creating a similar lift effect as a
conventional trim wedge due to the high pressure area behind the
propellers. The interceptor has proved to be more effective than a
conventional trim wedge in some cases, but so far it has been used only in
cruise vessels and RoRos. An interceptor is cheaper to retrofit than a trim
wedge.
• 1-5% lower propulsion power demand. Corresponding improvement of up
to 4% in total energy demand for a typical ferry.

16. Ducktail Waterline extension
• A ducktail is basically a lengthening of the aft ship. It is usually 3-6 meter
long. The basic idea is to lengthen the effective waterline and make the
wetted transom smaller. This has a positive effect on the resistance of
the ship. In some cases the best results are achieved when a ducktail is
used together with an interceptor.
• 4-10% lower propulsion power demand. Corresponding
improvement of 3-7% in total energy consumption for a typical ferry

17. Shaft Line Arrangement
• The shaft lines should be streamlined. Brackets should have a
streamlined shape. Otherwise this increases the resistance and
disturbs the flow to the propeller.
• Up to 3% difference in power demand between poor and
good design. A corresponding improvement of up to 2% in
total energy consumption for a typical ferry.

18. Improved Skeg Shape/trailling Edge
• The skeg should be designed so that it directs the flow evenly
to the propeller disk. At lower speeds it is usually beneficial to
have more volume on the lower part of the skeg and as little
as possible above the propeller shaftline. At the aft end of the
skeg the flow should be attached to the skeg, but with as low
flow speeds as possible.
• 1.5%-2% lower propulsion power demand with good
design. A corresponding improvement of up to 2% in total
energy consumption for a container vessel.

19. Minimizing Resistance of Hull Openings
• The water flow disturbance from openings to bow thruster
tunnels and sea chests can be high. It is therefore beneficial
to install a scallop behind each opening. Alternatively a grid
that is perpendicular to the local flow direction can be
installed. The location of the opening is also important.
• Designing all openings properly and locating them
correctly can give up to 5% lower power demand than
with poor designs. For a container vessel, the
corresponding improvement in total energy consumption
is almost 5%.

20. Air Lubrication
• Co pressed air is pu ped i to a re ess i the otto of the ship’s
hull. The air builds up a carpet that reduces the frictional resistance
between the water and the hull surface. This reduces the propulsion
power demand. The challenge is to ensure that the air stays below
the hull and does not escape. Some pumping power is needed.
• Saving in fuel consumption:
 Tanker: ~15 %
 Container: ~7.5 %
 PCTC: ~8.5 %
 Ferry: ~3.5%

21. Wing Thruster
• Installing wing thrusters on twin
screw vessels can achieve
significant power savings,
obtained mainly due to lower
resistance from the hull
appendages.
• The propulsion concept
compares a centre line
propeller and two wing
thrusters with a twin shaft line
arrangement.
• Result: Better ship
performance in the range of
8% to 10%. More flexibility in
the engine arrangement and
more competitive ship
performance.

22. Counter Rotating Propellers (CRP)
• Counter rotating propellers consist of a pair of propellers behind each
other that rotate in opposite directions. The aft propeller recovers some
of the rotational energy in the slipstream from the forward propeller.
The propeller couple also gives lower propeller loading than for a
single propeller resulting in better efficiency.
• CRP propellers can either be mounted on twin coaxial counter rotating
shafts or the aft propeller can be located on a steerable propulsor aft of
a conventional shaft line.
Image Credit: Japan Marine United
Corporation (JMU)
• CRP has been documented as the propulsor with one of the
highest efficiencies. The power reduction for a single screw
vessel is 10% to 15%.

23. Optimization of Propeller & Hull Interaction
• The propeller and the ship
interact. The acceleration of
water due to propeller action
can have a negative effect on
the resistance of the ship or
appendages. This effect can
today be predicted and
analyzed more accurately
using computational
techniques.
• Redesigning the hull,
appendages and propeller
together will at low cost
improve performance by up
to 4%.

24. Propeller-Rudder Combinations
• The rudder has drag in
the order of 5% of ship
resistance. This can be
reduced by 50% by
changing the rudder
profile and the propeller.
Designing these together
with a rudder bulb will
give additional benefits.
• Improved fuel
efficiency of 2% to 6%.

25. Advanced Propeller Blade Sections
• Advanced blade
sections will improve
the cavitation
performance and
frictional resistance of
a propeller blade. As
a result the propeller
is more efficient.
• Improved propeller
efficiency of up to
2%.

26. Propeller Tip Winglets
• Winglets are known
from the aircraft
industry. The design
of special tip shapes
can now be based
on computational
fluid dynamic
calculations which
will improve propeller
efficiency.
• Improved propeller
efficiency of up to
4%.

27. Propeller Nozzle
• Installing nozzles
shaped like a wing
section around a
propeller will save
fuel for ship speeds
of up to 20 knots.
• Up to 5% power
savings compared
to a vessel with an
open propeller.

28. Variable Speed Operation
• For controllable pitch
propellers, operation at
a constant number of
revolutions over a wide
ship speed reduces
efficiency. Reduction of
the number of
revolutions at reduced
ship speed will give fuel
savings.
• Saves 5% fuel,
depending on actual
operating conditions.

29. • Wing-shaped sails
installed on the deck or
a kite attached to the
bow of the ship use
wind energy for added
forward thrust. Static
sails made of composite
material and fabric sails
are possible.
• Fuel consumption
savings:
 Tanker ~ 21%
 PCTC ~20%
 Ferry ~8.5%

31. Flettner Rotors
• Spinning vertical
(Flettner) rotors
installed on the ship
convert wind power
into thrust in the
perpendicular
direction of the wind,
utilising the Magnus
effect. This means
that in side wind
conditions the ship
will benefit from the
added thrust.
• Fuel consumption
savings: ~30%

32. Steerable thrusters with a pulling propeller
• Steerable thrusters with a pulling propeller can give clear power savings.
The pulling thrusters can be combined in different setups. They can be
favorably combined with a centre shaft on the centre line skeg in either a
CRP or a Wing Thruster configuration. Even a combination of both
options can give great benefits. The lower power demand arises from
less appendage resistance than a twin shaft solution and the high
propulsion efficiencies of the propulsors with a clean waterflow inflow.
• The propulsion power demand at the propellers can be reduced by
up to 15% with pulling thrusters in advanced setups.

33. Hybrid Aux. Power Generation
• Hybrid auxiliary power system consists of a fuel cell, diesel generating set
and batteries. An intelligent control system balances the loading of each
component for maximum system efficiency. The system can also accept
other energy sources such as wind and solar power.
• Result:
 Reduction of NOX by 78%
 Reduction of CO2 by 30%
 Reduction of particles by 83%

34. Combined Diesel-Electric and
Diesel-Mechanical (CODED) Machinery
• Combined diesel-electric and
diesel-mechanical machinery can
improve the total efficiency in ships
with an operational profile
containing modes with varying
loads. The electric power plant will
bring benefits at part load, were the
engine load is optimised by
selecting the right number of
engines in use. At higher loads, the
mechanical part will offer lower
transmission losses than a fully
electric machinery.
• Total energy consumption for a
offshore support vessel with
CODED machinery is reduced by
4% compared to a diesel-electric
machinery.

35. Low Loss Concept (LLC)
• Low Loss Concept (LLC) is a patented power distribution
system that reduces the number of rectifier transformers
from one for each power drive to one bus-bar transformer
for each installation. This reduces the distribution losses,
increases the energy availability and saves space and
installation costs.
• Result: Gets rid of bulky transformers. Transmission losses
reduced by 15-20%.

36. Variable Speed Electric Power Generation
• The system uses generating
sets operating in a variable
rpm mode. The rpm is always
adjusted for maximum
efficiency regardless of the
system load. The electrical
system is based on DC
distribution and frequency
controlled consumers.
• Results:
 Reduces number of
generating sets by 25%
 Optimized fuel
consumption, saving 5-10%

37. LNG Fuel
• Switching to LNG fuel reduces
energy consumption because of
the lower demand for ship
electricity and heating. The
biggest savings come from not
having to separate and heat
HFO. LNG cold (-162 °C) can be
utilised in cooling the ship’s
HVAC to save AC-compressor
power.
• Saving in total energy < 4 %
for a typical ferry. In 22 kn
cruise mode, the difference in
electrical load is approx. 380
kW. This has a major impact
on emissions.

38. Waste Heat Recovery (WHR)
• Waste heat recovery (WHR) recovers the thermal energy from the
exhaust gas and converts it into electrical energy. Residual heat
can further be used for ship onboard services. The system can
consist of a boiler, a power turbine and a steam turbine with
alternator. Redesigning the ship layout can efficiently
accommodate the boilers on the ship.
• Exhaust waste heat recovery can provide up to 15% of the
engine power. The potential with new designs is up to 20%.

39. Engine Tuning
• Engine Tuning (Delta tuning on Wartsila 2-stroke RT-flex
engines) offers reduced fuel consumption in the load range
that is most commonly used. The engine is tuned to give
lower consumption at part load while still meeting NOx
emission limits by allowing higher consumption at full load
that is seldom used.
• Result: Lower specific fuel consumption at part loads
compared to standard tuning, can save upto 1% fuel.

40. Common Rail (CR) Fuel System
• Common Rail (CR) is a tool
for achieving low emissions
and low SFOC. CR controls
combustion so it can be
optimised throughout the
operation field, providing at
every load the lowest possible
fuel consumption.
• Result:
 Smokeless operation at all
loads
 Part load impact
 Full load impact
 Save upto 1% fuel.

41. Energy Saving Lighting
• Using lighting that is more electricity and heat efficient
where possible and optimizing the use of lighting
reduces the demand for electricity and air
conditioning. This results in a lower hotel load and
hence reduced auxiliary power demand.
• Results: Fuel consumption saving: Ferry and
Passenger vessel 1~2%

42. Efficient Power management
• Power Management: Correct timing for changing the number of
generating sets is critical factor in fuel consumption in diesel
electric and auxiliary power installations. An efficient power
management system is the best way to improve the system
performance.
• Result: Running extensively at low load can easily increase
the SFOC by 5-10%. Low load increases the risk of turbine
fouling with a further impact on fuel consumption.

43. Solar Power
• Solar panels installed on a
ship’s deck can generate
electricity for use in an electric
propulsion engine or auxiliary
ship systems. Heat for various
ship systems can also be
generated with the solar
panels.
• Depending on the available
deck space, solar panels can
give the following reductions
in total fuel consumption:
 Tanker: ~ 3.5%
 PCTC: ~ 2.5%
 Ferry: ~ 1%

44. Variable Speed Control Pump & Fan
• Pumps are major energy consumers
and the engine cooling water system
contains a considerable number of
pumps. In many installations a large
amount of extra water is circulated
in the cooling water circuit.
Operating the pumps at variable
speed would optimise the flow
according to the actual need.
• Pump energy saving (LT only)
case studies:
 Cruise ships (DE) 20-84%
 Ferry 20-30%
 AHTS 8-95%

45. Integrated Automation System (IAS) or Alarm
and Monitoring System (AMS)
• An Integrated Automation System (IAS) or
Alarm and Monitoring System (AMS)
includes functionality for advanced
automatic monitoring and control of both
efficiency and operational performance.
• The system integrates all vessel
monitoring parameters and controls all
processes onboard, so as to operate the
vessel at the lowest cost and with the best
fuel performance.
• Power drives distribute and regulate the
optimum power needed for propeller
thrust in any operational condition.
• Engine optimization control, power
generation & distribution optimisation,
thrust control and ballast optimisation
give 5-10% savings in fuel
consumption.

46. Advanced power Management
• Power management based on intelligent control
principles to monitor and control the overall efficiency and
availability of the power system onboard. In efficiency
mode, the system will automatically run the system with
the best energy cost.
• Reduces operational fuel costs by 5% and minimizes
maintenance.

47. SEEMP related measures:
Source: MEPC 63, IMO.

48. Turnaround Time in Port
• A faster port turnaround time
makes it possible to decrease
the vessel speed at sea. This is
mainly a benefit for ships with
scheduled operations, such as
ferries and container vessels.
The turnaround time can be
reduced for example by
improving maneuvering perform
ance or enhancing cargo flows
with innovative ship designs,
ramp arrangements or lifting
arrangements.
• Results: Saving upto 10%
fuel.

49. Propeller Surface Polishing
• Regular in-service
polishing is required to
reduce surface
roughness on propellers
caused by organic
growth and fouling. This
can be done without
disrupting service
operation by using
divers.
• Results: Up to 10%
improvement in service
propeller efficiency
compared to a fouled
propeller.

50. Hull Surface Coating
• Modern hull coatings have a smoother and
harder surface finish, resulting in reduced
friction. Since typically some 50-80% of
resistance is friction, better coatings can
result in lower total resistance.
• A modern coating also results in less
fouling, so with a hard surface the benefit is
even greater when compared to some older
paints towards the end of the docking
period.
• Saving in fuel consumption after 48
months compared to a conventional hull
coating:
 Tanker: ~ 9%
 Container: ~ 9%
 PCTC: ~ 5%
 Ferry: ~ 3%
 OSV: ~ 0.6%

51. Part Load operation Optimization
• Engines are usually
optimized at high loads. In
real life most of them are
used on part loads. New
matching that takes into
account real operation
profiles can significantly
improve overall operational
efficiency.
• New engine matching
means different TC tuning,
fuel injection advance,
cam profiles, etc.

52. Slow Steaming
Reducing the ship speed an effective way
to cut energy consumption. Propulsion
power vs. ship speed is a third power curve
(according to the theory) so significant
reductions can be achieved. It should be
noted that for lower speeds the amount of
transported cargo / time period is also
lower. The energy saving calculated here is
for an equal distance travelled.
• Reduction in ship speed vs. saving
in total energy consumption:
 0.5 kn –> – 7% energy
 1.0 kn –> – 11% energy
 2.0 kn –> – 17% energy
 3.0 kn –> – 23% energy

53. Voyage Planning & Weather Routing
• The purpose of weather routing is to find the optimum route for long
distance voyages, where the shortest route is not always the fastest.
The basic idea is to use updated weather forecast data and choose
the optimal route through calm areas or areas that have the most
downwind tracks. The best systems also take into account the
currents, and try to take maximum advantage of these. This track
information can be imported to the navigation system.
• Shorter passages, less fuel, save upto 10% fuel.

54. Optimum Trim
• The optimum trim can often be as much as 15-20% lower than the worst
trim condition at the same draught and speed. As the optimum trim is hull
form dependent and for each hull form it depends on the speed and
draught, no general conclusions can be made. However by logging the
required power in various conditions over a long time period it is possible
to find the optimum trim for each draught and speed.
Fig: Computational Fluid Dynamics
• Or this can be determined fairly quickly using Computational Fluid
Dynamics (CFD) or model tests. However it should be noted that
correcting the trim by taking ballast will result in higher consumption
(increased displacement). If possible the optimum trim should be achieved
either by repositioning the cargo or rearranging the bunkers.
• Optimal vessel trim reduces the required power.

55. Autopilot Adjustments
• Poor directional stability causes
yaw motion and thus increases
fuel consumption. Autopilot has
a big influence on the course
keeping ability. The best
autopilots today are self tuning,
adaptive autopilots.
• Finding the correct autopilot
parameters suitable for the
current route and operation
area will significantly reduce
the use of the rudder and
therefore reduce the drag.
• Finding the correct
parameters or
Preventing unnecessary use
of the rudder gives an
anticipated benefit of 1-5%.
Source: Wärtsilä

56. Hull Cleaning
• Algae growing on the
hull increases ship
resistance. Frequent
cleaning of the hull can
reduce the drag and
minimise total fuel
consumption.
• Reduced fuel
consumption:
 Tanker: ~ 3%
 Container: ~ 2%
 PCTC: ~ 2%
 Ferry: ~ 2%
 OSV: ~ 0.6%

57. Conditioned Based Maintenance (CBM)
• In a CBM system all
maintenance action is based
on the latest, relevant
information received through
communication with the
actual equipment and on
evaluation of this information
by experts.
• The main benefits are: lower
fuel consumption, lower
emissions, longer interval
between overhauls, and
higher reliability.
• Correctly timed service will
ensure optimum engine
performance and improve
consumption by up to 5%.

58. Energy Saving Operation Awareness
• A shipping company, with its human resources department,
could create a culture of fuel saving, with an incentive or
bonus scheme based on fuel savings. One simple means
would be competition between the company’s vessels.
Training and a measuring system are required so that the
crew can see the results and make an impact.
• Historical data as reference. Experience shows that
incentives can reduce energy usage by up to 10%.

59. Climate Change Awareness for
Ship owners and Managers
• IMO’s Second GHG Study (2007) which published in 2009, identified
that CO2 emissions from international shipping accounted for
approximately 2.7% of total anthropogenic (caused by human
activity) CO2 emissions in 2007. If no regulatory measures were
developed, CO2 emissions were projected to grow between 200%
and 300% by 2050, despite significant market-driven efficiency
improvements.
• The adoption by IMO of mandatory reduction measures for all ships
from 2013 and onwards will lead to significant emission reductions
and also a striking cost saving for the shipping industry. By 2020, up
to 200 million tonnes of annual CO2 reductions are estimated from
the introduction of the EEDI for new ships and the SEEMP for all
ships in operation, a figure that, by 2030, will increase to 420 million
tonnes of CO2 annually. In other words, the reductions will in 2020
be between 10 and 17%, and by 2030 between 19 and 26%
compared with business as usual.

60.  The reduction measures will also result
in a significant saving in fuel costs to
the shipping industry, although these
savings require deeper investments in
more efficient ships and more
sophisticated technologies than the
business as usual scenario. The annual
fuel cost saving estimates states a
staggering figure of $20 to 80 billion by
2020, and even more astonishing $90 –
310 billion by 2030.
So, Ships owners and managers
climate change awareness can
reduce significant amount of CO2
Emissions by introducing new
technology innovations to world fleet
and save $20 to 80 billion fuel cost
by 2030.
Image Credit:
transitionsoutheast.org.uk

61. References:
1. www.gcaptain.com (How to Design a More Efficient Ship, How to
Propel a More Efficient Ship, Marine Engineering Technology for
More Efficient Shipping and Operational and Maintenance factors
and their impact on a vessel’s efficiency by ROB ALMEIDA)
2. www.wartsila.com (For all information, images)
3. Assessment of IMO mandated energy efficiency measures for
international shipping (MEPC 63/inf.2 www.imo.org)
4. Reducing emissions and improving energy efficiency in
international shipping by Koji Sekimizu, Secretary-General,
International Maritime Organization (IMO)
5. Skysails, Beluga Group.
6. U.S. Department of Energy

62. For more information please see:
www.imo.org