Study of Catamaran Fishing Vessel Based on Solar Energy

Projected temperature that will be felt by world community will increase 7.5°C hotter in 2070, meaning that world community is threatened to live in extreme temperatures an average of 34°C in next 50 years. This prediction can occur if a reduction in greenhouse gas emissions fails to be carried out simultaneously. On or hand, impact of soaring crude oil prices on world market has been felt by all walks of life so it is necessary to create alternative solutions to dependence of fuel to get through difficult times. In sea transportation sector, use of fuel for motorized ships is not only uneconomical but also not environmentally friendly. Dependence on fossil fuel energy has led to development of energy-efficient ship concepts that use alternative energy sources in moving ships. This is anticipated by use of solar energy in form of Electricalboats (Eb) which are applied as fishing vessels. This paper presents a study of efficient use of solar energy in Eb as a boat driver that does not utilize fuel for development of environmentally friendly fishing vessels. Technical analysis is done through testing ship model in Towing Tank n results are explored with Naval Architect ories. In conclusion, there is a potential for fuel consumption savings of up to 90% when compared to ships that only use conventional engines.


Introduction
Projected temperature that will be felt by world community will increase 7.5°C hotter in 2070 meaning that world community is threatened to live in extreme temperatures an average of 34°C in next 50 years, this prediction can occur if reduction in greenhouse gas emissions fails to be carried out simultaneously, [2] Behind a threat to a certain condition re is an opportunity, namely utilization of solar energy.
Potential of solar energy sources in Indonesia reaches an average of 4.5 kWh per square meter per day because of Indonesia's geographical location in equatorial region so that Indonesia's territory will always be illuminated by sun for 10-12 hours a day and shine around 2000 hours per year, so Indonesia is classified as a rich source of solar energy, [4].
On or hand, impact of soaring crude oil prices on world market has been felt by all walks of life which makes it even more burdensome. In response to this, austerity movements in various sectors are needed by creating alternative solutions to dependence on fuel to overcome se difficult times, [6].
In sea transportation sector, ship operations are always associated with economic problems (operational costs) and environment ( level of pollution that occurs due to ship operations), [7]. Reduction of engine power (and fuel requirements) can be met since design phase by creating an efficient hull design and propulsion system, [9].
Catamaran hull has a large deck area, small obstacles, stability and good ship motion (seakeeping). This means that catamaran hull has potential to reduce amount of propulsion and exhaust emissions that occur, [12]. Whereas fulfillment of need for an efficient propulsion system can be created with use of alternative energy, such as: Hybrid Engine Ships, Solar Electric Ships, Sailboats, Solar Electric Ships, Hybrid Engine Ships, [8]. At present fishing vessels are still urgently needed to support and maintain food security for billions of people in this world, [10]. In operation of fishing vessels must be absolutely safe because even in bad wear ship must work, so problem of total obstacles, driving force, fuel consumption, stability and seakeeping are very important issues, [11]. Meanwhile, number of fishing vessels using catamaran hulls is still very limited. Catamaran hull is very suitable to be used as a fishing vessel, [14].

Methods
This research was conducted through testing ship model in Test Pool n results were explored with Naval Architect ory. This research is continuing and all material data information uses results of previous research to support scientific / academic and its application, [15].

Ship Resistances Testing
Main measurements of catamarans and results of ship resistance experiments in Towig Tank using lots of data from experiments conducted at ITS, [14].      Figure 3 shows forces acting on ship's propulsion system when operating. ship can move forward because of thrust (T) that is sufficient to reolve ship resistances (RT) at a certain service speed (VS), [5].

Data Exploration • Ship Movement ory
where: t = kR . wt where: t is thrust deduction factor for single screw, kR is 0.5 for thin rudder.
Use formulae of Engine Power, [5]: Effective power (PE) = RT . VS Delivered power (PD) = PE/ ηD (8) Quasi propulsive coefficient (ηD) = ηP. ηH. ηR (9) Service power (Ps) = PD/ ηT (10) There are several arrangements of power transmission that are often used on ship propulsion systems: P watt peak = PV area x PSI x ηpv (15) • Ship Stability Stability is ability of a ship to return to its initial position after experiencing heels caused by external forces i.e: waves or wind.
Stability requirement for catamarans is that angle φ at maximum GZ value must not be less than or equal to 10º (HSC, 2000).

• Ship motion (Seakeeping)
Seakeeping is motion response of ship when it receives a disturbance from external due to wave blows or in or words is one aspect of hydrodynamics that studies behavior of ships on waves, [1].

Waves Ship motions
where:  is Amplitudo of ship motion response, a  adalah Amplitudo of sea waves.

• Selection of Engines and Electric Motors
Installed engine power (PI) is 60 kW with a total efficiency (PE / PI) of 54%. engine used is 2 x 30 kW or 2 x 43 hp. Figure 6. Hybrid diesel engine with specifications Figure 6 shows a hybrid diesel engine, where engine is equipped with an alternator motor that is able to provide power as an Electric Drive to move ship and as a Generator to supply electricity to battery. Table 3. Results of data development Table 3. shows a resume of Eb propulsion system data development results which was carried out through testing ship model in Towing Tank and n results were explored with Naval Architect ories.  Table 4. shows a resume of Ship Performance data development results as an literary analysis by Naval Architect theories.

Vs (knots)
Rpm-PE Rpm-Vs Figure 7 shows an operational simulation of a Solar Electric Catamaran Fish Boat. In its operations, fishing vessels must be absolutely safe (very seaworthy indeed)), even in bad wear ship must work. Figure 8 shows work scheme of Solar Electric Catamaran Fish Boat (Eb) system which can be explained in detail as follows: Solar panels placed above canopy and deck of ship function to capture solar energy and convert it into electrical energy, n stored in batteries. Solar panels that have an area of 80 m 2 are capable of producing electrical power of 1.67 kW with a charging time for 1.1 hours / batt. Charging a battery with a capacity of 30 kW is also done through an alternator electric motor (45 Amp, 12 Volt) which is available under diesel engine power and only takes 1 hour. power stored in battery will be used to supply electric motor and rotate propeller as an Electric Drive, so ship can move forward due to thrust generated by propeller. A 30kWh battery can provide electricity for 6 to 8 hours. In addition, this Eb does not produce exhaust emissions and is not noisy so it does not interfere with operation of ship when fishing, beneficial and environmentally friendly.  Figure 9. shows relationship between rpm and power and torque produced by an Electric Motor. Torque is very closely related to thrust (thrust). more engine rpm value increases, greater engine power generated so that need for thrust (thrust) will increase as well. When engine speed is 2800 rpm, power value is 30 kW with a torque of 108 Nm. But when engine speed drops to around 1650 rpm, power used is only about 21 kW and torque produced is around 128 Nm. Similarly, when engine speed drops to around 900 rpm, power used is only about 8 kW so torque value drops to around 105 Nm. Figure 10. shows relationship between rpm and power and speed. Ships (Vs). more engine rpm value increases, greater engine power and Ship speed.
Economic value of fuel use on fishing vessels is shown in Figure 11 below, [14]. Figure 11. Relationship between Vs -FC -T at 60 kW power Figure 11. shows a graph of relationship between ship speed (Vs) -fuel consumption (FC) -thrust (T). To reach official speed Vs 9.8 knots with a driving force (P) of 60 kW, thrust of ship (T) of 6,685 kN requires a fuel consumption (FC) of 57.9 liters / hour. So it can be said that economic value of speed of ship (Vs) of 9.8 knots, thrust (T) of 6,685 kN is equivalent to cost of fuel consumption of 57.9 liters / hour. efficiency of engine drive transmission system is 0.98, while electric motor drive is 0.89. If economic value of engine drive (fossil energy) used is equated with economic value of electric motor drive (solar energy) obtained is speed of engine driving boat Vs of 1 knots is equivalent to speed of boat moving fish solar panel Vs about 0.9 knots, it can be simply concluded that solar energy needed to drive a ship of 1 knots is equivalent to fuel consumption of 5.3 liters / hour.
The results of Eb catamaran fishing vessel static stability calculation (in various operational conditions), are as shown in Table 5.  Catamaran motion is very dependent on choice of distance between hull (S/L) and on distance S/L = 0.2 RAO value is 18% smaller than S/L = 0.4 in direction of wave 120 o , as obtained in [16].

Conclusions
Application of solar energy on catamaran fishing vessels is very useful (Eb) and has potential of cost savings of around 90% fuel consumption, also can reduce greenhouse gas emissions. This work is a portrait of a study of development of energy efficient fishing vessels and reducing air pollution.