Aditya, India’s first solar ferry, is a solar-powered ferry operating between Vaikkom and Thavanakkadavu in the Indian state of Kerala. The boat was inaugurated by Kerala Chief Minister Sri. Pinarayi Vijayan and Central Cabinet Minister for Power, Renewable Energy, Sri. Piyush Goyal on January 12, 2017. It is India’s first solar-powered ferry and the largest solar-powered boat in India. The vessel was designed and built by Naval Solar and Electric Boats in Kochi, India. NavAlt is a joint venture firm between Navgathi Marine Design and Constructions, Alternative Energies (France) and EVE Systems (France).
The boat is operating since launch on 12 January 2017 between Vaikkom and Thavanakkadavu. The first150 days operation data shows that even rainy days during monsoon did not affect the schedule of the boat.
The boat was launched on November 9, 2016. After that, multiple sets of tests and trials were conducted to verify the operational characteristics and safety standards of the boat.
The 20-meter-long and 7-meter-wide boat is covered by 140 m2 of solar panels rated at 20 kW, which in turn connect to two electric motors of 20 kW, one in each hull. There are 700 kg of lithium-ion batteries in the ship’s two hulls with a total capacity of 50 kWh. The catamaran hull and its shape allow to reach speeds of up to 7.5 knots. Kerala Port surveyor and technical committee. The hull was designed based on the extensive experience of Navgathi and AltEn and extensive computational fluid dynamics (CFD) was made to determine its hydrodynamics. The boat is designed to be used as a passenger ferry between Vaikom and Thavanakadavu. The normal operating speed is 5.5 knots (10 km / h) to achieve a 15-minute travel time between Vaikom and Thavanakkadavu, a distance of 2. 5 km on water. For achieving this speed, the power needed is about 16 kW. During maneuvering, when leaving the jetty or approaching it, about 22 kW of power are needed. Hence, we average 20 kW power is needed. The total running time, neglecting the time in jetty for embarking and disembarkation of passengers, is 5.5 hours on a sunny day (depending on customer needs). Although the maximum power required is a total of 22 kW during maneuvering and 16 kW, the total of 40 kW, is provided in two motors of 20 kW each. The two systems on the side of the boat (in each half-Hull) are electrically independent to ensure redundancy in the case of system failure in one. Even if one system fails the power is available to shore. Also, unlike diesel engines, since it does not drop with load, the electric motors can only operate at 50% load and in emergencies at 100%. For higher safety standards and reliability, the Vaikom – Thavanakkadavu road. The boat is being surveyed by Kerala Port surveyor on November 16, 2016, near in backwaters at Aroor. The boat is registered in Kodungallur Port under Kerala Ports. The boat is remotely monitored and can also be remotely. All the operating parameters of the boat are recorded and transmitted to the Naval Solar and Electric Boats where the technical experts can monitor the boat. The upgrades and settings in the software can also be performed remotely as if a computer is plugged on the boat. This makes the boat even more safe. The project cost was US $ 370,000.
The boat satisfies the Indian Register of Shipping’s safety requirement of being able to maintain propulsion shut down.
The total energy needed to operate the ferry for 5.5 hours is 110 kWh (20 kW is average power). 1 kW solar panels produce 4 kWh of energy per day, and average for the year. Hence the energy from solar panels is 80 kWh. The gap in energy is provided by 40 kWh (80% discharge) from a total capacity of 50 kWh. The lithium batteries are fully charged in the morning because of overnight grid charging. A trip between the two boat points takes 15 minutes and it needs energy of 5 kWh. Hence a total of 22 trips can be made daily transporting 1,650 people daily, or 580,000 people every year without burning fuel. Trips on average sunny day: 7:00 AM to 7:00 PM (running hours 5.5 hours) The below table describes the 22 trips in each column, and for each trip the start and end time. It also lists the break time at the end of each trip. In non-peak hours this is about 15 minutes, in peak time it is 10 minutes and around noon it is two hours. The energy from the sun is cumulative from 72 kWh from 18 kW (the rest is for auxiliary systems and charges a different battery bank). The battery state of charge (SOC) is shown at the beginning of the trip and end of trip. At the end of the day, the battery has about 20% charge left. The energy can be increased by adding one more trip (5 kWh usage) so that end of day SOC can be 10%. We have bright sunny day, the no. Breaks can be increased by taking trips during 11:55 to 14:05 break. About more trips can be made in this period. We have cloudy day, the no. of trips is reduced and the break time is increased. If it is very cloudy in the break time, then shore charging can be done. This is a 32A charger and charges at 7 kW. Hence in the three hour break, it can charge battery by 21 kWh.
Compared to a conventional diesel engine with 238,000 US dollars, the solar ferry costs 370,000 US $. An efficient regular consumes 120 liters per day (12 liters per hour), gold 3,500 liters per month and 42,000 liters per year of diesel. This amounts to US $ 39,000 for diesel (US $ 0.93 / liter) and US $ 44,600 per year. The operating cost of solar ferry is 40 units of electricity or US $ 6.2 per day which amounts to US $ 185 per month and US $ 2,150 per year. The pay back period is under three years. The Government of India under the leadership of Prime Minister, Sri. Narendra Modi is very supportive of the project and the Ministry of New and Renewable Energy has also agreed to consider the project as one of its kind in India. The benefit of sponsorship would mean that Kerala State Water Transportation Department would get the boat at almost free cost. In this scenario the boat is cheaper than one and they would start saving money from day one.