• The industry problem

• Setting priorities and directions

• Energy management

• Energy audits/industry development

• Research

• Alternative fuels and energy

• Fishing gear and propulsion

• Hull characteristics and efficiency

Reducing the production costs of commercial fishing in the face of a “Double Crisis”.

Oil Deficit + Global Warming

David Sterling

“What is the fuel crisis?” really starts with another question:

What’s so good about diesel fuel?

Answer:

• Low cost

• High volumetric energy density (36.3 MJ/litre)

(1 litre of diesel has the combustion energy equivalent to the work of lifting a weight of 37 tonne to a height of 100 m - 37cars to top of 30 story building!)

• It is a liquid that is safe and easy to store and distribute

(high flash point, easily pumped, stable at room temp and pressure)

• Wide ranging and flexible energy source due to well developed supporting technologies.

Petro-diesel has become entrenched in commercial fishing.

In fact the diesel engine was the “enabling” technology for the modern fishing fleets we see today.

High procurement cost is partly due to dwindling oil supply (“plateau” production rate), accentuated by rapidly expanding demand.

Three (+1?) broad components to fuel price

• Supply chain price• GST• Excise - government tax, generally credited back

to primary producers (in Aus)• Carbon “Tax”?? – Future tax to fund “balancing”

carbon sequestration

Objective: Increase fishing profitability

• Increase revenue– Improve market price– Increase volume of production

• Reduce operating costs?

Revenue

ProfitCosts

Historical Diesel Prices in Brisbane

0

20

40

60

80

100

120

140

160

180

200

Jan-04

Apr-04

Jul-04

Oct-04

Jan-05

Apr-05

Jul-05

Oct-05

Jan-06

Apr-06

Jul-06

Oct-06

Jan-07

Apr-07

Jul-07

Oct-07

Jan-08

Apr-08

Die

sel

Pri

ce (

cen

ts/l

)

Terminal Gate Price of diesel

Cost price of diesel to fishers

Fuel price to fishers has increased by 3 times since 2004

Conclusions from the perspective of energy efficiency

• Raise industry awareness, at the enterprise level, of energy management / development

• Roll out energy audits to:– Benchmark industry performance– Gather information on factors affecting energy efficiency– Kick start cycles of enterprise level industry development

• Undertake key research and development activities to support industry development, including:– Commercialise Batwing otter boards– Practically integrate "high strength" netting into commercial trawl gear– Seek improvements to course control systems– Improve motion stabilising equipment– Utilise engine waste heat– Investigate practical renewable energy sources from the fishing

environment.

Energy Management System

Systemic changes

Reduce fuel waste - Fuel monitoring

Policy/Responsibility/auditing – Skipper Incentive

Energy Audits

What needs to be done?• Reduce the unit cost of energy input• Reduce the amount of energy used (per kg of production)

What is the purpose of fuel?

• To supply vessel propulsion. Why?– To move the boat from place to place.– To tow trawl gear

• To generate electricity. Why?– To run electrical appliances– To produce light– To run large capacity refrigeration

• To generate hydraulic power. Why?– To operate winches and capstans

• To produce a source of heat. Why?– To cook seafood – To create hot water

Where does one start?Energy tree for Qld east coast prawn trawler

Input Energy

Diesel (98%)

LPG (2%)

IC e

ngin

e (9

8%)

Hea

t (2

%)

Point to point travel (20%)

Tow trawl gear (80%)

Pro

puls

ion

(70%

)

AC

/DC

ele

ctric

ity

(25%

)

Electrical appliances (15%)

Lighting (8%)

Cook seafood products (95%)

Domestic hot water (5%)

Freezing/Refrigeration (50%)

Hyd

raul

ic p

ower

(5

%)

Run try winch (20%)

Run trawl winches (95%)

Capstans/anchor winch (5%)

Run auto pilot (5%)

Sea water supply (2%)

Where does one start?Energy tree for Qld east coast prawn trawler

Input Energy

Diesel (98%)

LPG (2%)

IC e

ngin

e (9

8%)

Hea

t (2

%)

Point to point travel (13.7%)

Tow trawl gear (54.9%)

Pro

puls

ion

(68.

6%)

AC

/DC

ele

ctric

ity

(24.

5%)

Electrical appliances (3.7%)

Lighting (2%)

Cook seafood products (1.9%)

Domestic hot water (0.1%)

Freezing/Refrigeration (12.3%)

Hyd

raul

ic p

ower

(4

.9%

)

Run try winch (4.9%)

Run trawl winches (4.7%)

Capstans/anchor winch (0.2%)

Run auto pilot (1.2%)

Sea water supply (0.5%)

Diesel (98%)

Alternative fuels:

• The dominant direction for fishing is to stick with liquid fuels

• The bulkiness and expense of gas fuel (even highly compressed) is difficult - particularly for large periods at sea and remote locations

• LPG and LNG are worth consideration, but expensive to convert and medium term benefits are uncertain.

• Biodiesel is not an option because sale price does not contain an excise component that can be rebated.

• Its feasible that production of synthetic diesel from coal and natural gas will become established to underpin and stabilise the price of a blended diesel fuel.

Specific fuel consumption versus rated engine output

0

50

100

150

200

250

300

1 10 100 1000 10000 100000

Rated engine output (kw)

Sp

ec

ific

fu

el c

on

su

mp

tio

n

(g/k

w/h

r)

Specific fuel consumption versus rated engine speed

0

50

100

150

200

250

300

1 10 100 1000 10000

Rated engine speed (RPM)

Sp

ec

ific

fu

el c

on

su

mp

tio

n

(g/k

w/h

r)

Engine Efficiency

Important research directions:• Lower speed engines are more efficient than high speed engines.• May be able to utilise waste heat (up to 60% of fuel energy).• Injection of small amounts of hydrogen or other gaseous fuels such as LPG may enhance combustion and efficiency.

Data plotted from Baird (1999), “World Engines and Propulsion Systems”

Fuel efficiency in fishing context

Fuel

Thrust

TimePrawn behaviour Natural

environment

Available thrust

Speed Span

Prawn availability

Revenue = Swept area rate X Trawling time X Catch efficiency X Local abundance X Sale price

Natural resources and services

Human endeavour/ technology/capital

+

Propulsion system

Hull and appendage

drag

Fishing gear

NetsOtter boards

Timemanagement

Fishinggear

Stocksize

Searching power

Marketing

Processing

Demand

5%

2%

31%

62%

Resistance components of a 22m LWL Success class trawler trawling at 3 knots with double-rigged 16fm nets. Total resistance = 25.3kN.

Otter boards 7.9kN (31%)

Nets & wires 15.7kN (62%)

Paravane resistance 0.4kN

(2%)

Hull resistance 1.3kN (5%)

4 X 6 ftm Qua d Rig

2 X 1 2 ftm Do u ble Rig

3 X 8 ftm T rip le Rig

Sin gle 2 4 ftm Ne t

D rag p er Ne t = .667D rag per Board pai r = .333

T O TAL DRAG = 1

D rag p er Ne t = 1/4 X .667 = .167D rag per Board pai r = 1/4 X .333 = .083

T O TAL DRAG = 2 X .167 + 2 X .083 = .5

D rag p er Ne t = 1 /9 X .667 = .074D rag per Board pai r = 1/9 X .333 = .037

T O TAL DRAG = 3 X .074 + 1 X .037 = .259

D rag p er Ne t = 1 /16 X .66 7 = .042D rag per Board pai r = 1 /16 X .333 = .021

T O TAL DRAG = 4 X .042 + 2 X .021 = .208

5 X 4.8 ftm Five Rig

Seabed contact 8%

Board drag 31%

Netting drag 61%

Seabed contact 9%

Board drag 30%

Netting drag 61%

Seabed contact 11%

Board drag 13%

Netting drag 76%

Seabed contact 12%

Board drag 18%

Netting drag 70%

Seabed contact 13%

Board drag 8%

Netting drag 79%

Contemporary prawn trawling rigsGoing one

step further?

What is the effect of reducing twine diameter?

What is the effect of improving otter board efficiency?

Amikan 24ply twisted polyethylene – single knot (1.65 mm diameter)

Extensively used in the ECTF.

Polyethylene Dyneema(approx. 90 kg B.S.) (approx. 140 kg B.S.)

The above dyneema netting is therefore 50% stronger and has 35% less diameter.

But is 8 times more expensive and has generated operational problems during trials.

Van Beeleen 1.0 mm twisted – single knot

Trialled in SA, Qld and NPF from the mid 90’s.

Hampidjan 1.0 mm braid, impregnated with Duracoat for increased stiffness – single knot (superseded)

Trialled in WA and NPF during late 90’s.

Hampidjan 1.1 mm braid, with mono-filament core for greater stiffness – double knot

Trialled in NPF in 2005.

Development of Batwing otter boards

-12.8

5.4

-3.4

3.6

-15

-10

-5

0

5

10

Drag Span

Tre

atm

en

t E

ffe

ct

(%)

Batwing boards

Soft-Brush Ground Gear

Development of Soft-brush ground gear

41%

32%

2%

2%

23%

Resistance components of a 22m LWL Success class trawler steaming at 9 knots with paravanes deployed. Total resistance = 23.5kN.

Effective power = 146hp.

Hull wave resistance 7.4kN

(32%)

Hull viscous resistance

9.7kN (41%)

Paravane resistance 5.4kN

(23%)

Cooling pipes 0.4kN (2%)

Wind resistance 0.6kN (2%)

Short-Term Possibilities:

Optimal vessel operation Retro-fit bulbous bow Bottom cleaning regime Appendage reduction Aerofoil rudder Displacement reduction Low drag motion stabilizers

Hull characteristics and efficiency

Long-Term Possibilities

New vessels Hull form optimisation New hull types e.g. catamarans

L/B ratio Displacement reduction e.g. aluminium superstructure Transom drag Round bilge

Hull characteristics and efficiency

Reducing the production costs of commercial fishing