White Paper on Solar Boats
9Pages

Sandith Thandasherry WHY DO WE NEED SOLAR BOATS? 
 Solar boats are significantly better boats Normally such functional and performance than conventional boats because they: s p e c i fi c a t i o n s a re m a d e t o m a t c h conventional boats. Solar boats are very effective in passenger ferries where the do not release harmful emissions in air propulsion power needed is less (unlike are very silent and comfortable for high speed boats, tugs, trawlers, cargo vessels) and operating time is whole of day. have low vibrations no smell of diesel or petrol A successful solar boat project requires two have lower cost of ownership (high different but critical focus areas: initial cost but low operating cost) Reduction in Propulsion power A solar boat design process is completely Optimisation of Energy management different from that of a conventional boat so much so that it can be termed as “solar It is challenging to design solar ferries that boat design philosophy.” It starts with run over 6 hours daily and almost every day defining functional and performance needs. in a year, compared to solar cruise boats NavAlt Solar & Electric Boats

Sandith Thandasherry that run 3 hours daily and 200 days in a (displacement, draft, trim, speed) so that the resistance of the boat is minimum. Fore-body and aft-body shape is optimised Reduction in Propulsion power The first critical step is to drastically reduce 3) The propulsion power is also reduced by the propulsion power compared to a reducing the weight of the boat. The conventional boat. This is achieved by five greatest contributor to a boat weight is the different process, all of which are hull. Solar boats are almost always built of c o m p o s i t e ( F R P, C a r b o n fi b re ) o...

Sandith Thandasherry Once the above steps are followed, the equator receives more solar energy than propulsion power needed for a solar those far away and bright sunny day passenger boat compared to a receives more energy from sun than a conventional boat is half in case of comparable composite boat and less than one-third of a steel boat. Optimisation in Energy management The battery bank is designed based on number of running hours of the boat when these running hours are Once the propulsion power is finalised the design condition (available energy from motor power is decided. Motors have...

Sandith Thandasherry sunny day. This also changes between Large solar ferries are usually four times costlier than a conventional single hull steel ferry. However if one raises the ergonomics The depth of discharge allowed for longer life of battery depends on type of battery classification society) of the conventional which will in turn drive the battery bank boat similar to that of solar ferries the ratio size. For example lithium batteries can be discharged by 80% compared to 50% for lead-acid batteries. At this depth of The consumable cost (fuel and lubes) is discharge lithium batteries...

Sandith Thandasherry Case Study of 75 Pax Solar Boat performance in terms of lowest resistance. This selection of hull was based on TOPOLOGY OF PORT SIDE ELECTRIC SYSTEM optimisation using computational fluid To transport 75 passengers across a 1.1 nautical miles (2 km) backwater stretch of Kerala at 5.5 knots average speed in a solar ferry built under IRS class. The energy storage size is to be designed for sunny condition to reduce the cost (reduce size of MPPT For providing comfortable seating for 75 passengers and 3 crew, a catamaran with battery bank). charge controller Discharge...

Sandith Thandasherry dynamics (CFD). This hull needs about 16 focus during rush hour hours in morning kW to propel at 5.5 knots and about 22 kW and evening. This translates to total energy during manoeuvring for short period leading between energy needed and obtained from motors of 20 kW power are selected ensuring 100% redundancy. At full power battery. Since lithium batteries can be the boat will cruise at 7.5 knots. discharged by 80% the battery bank need to be at least 45 kWh. A 50 kWh battery For Kerala, the average solar energy bank of lithium iron magnesium phosphate production from...

Sandith Thandasherry normal operation motors will operate at sunny day the boat can run for 6 hours and on a cloudy/rainy day it can run 5 hours (charging from grid during the noon break). There is a separate solar panel group (1.5 kW), separate battery bank (24V, 300 Ah) Economic Analysis for utilities. These include indoor LED lights, A conventional 75 passenger ferry that has navigation lights, fire pump, bilge pumps, to be build with similar ergonomics and electric horn, bulkhead lamps, search safety standards under classification lights, wiper motor, battery management society approval...

Sandith Thandasherry Initial Cost Lube Cost subsidy of 45 lakhs (capital subsidy and Fuel Cost Mcy Maintenance custom duty waiver for solar equipment) i.e., 45 lakhs, thereby a net price of 2.55 Crore. The total cost of a conventional ferry and that of a solar ferry is listed in the two graphs above. If we were to compare the total cost of ownership between the two boats, see graph below. 85 Conventional boat Solar boat Initial Cost Grid charging The above graph shows that although solar boats have higher upfront costs, the total cost of ownerships is lower. This boat has a break-even...

Sandith Thandasherry About NavAlt NavAlt is a joint venture between the three AltEn (Alternative Energies), France is the firms, a private limited company registered world’s leading solar ferry builder from in India, with ownership stake as Navgathi France. They have successfully designed and build 15 solar ferries from 30 to 75 passengers. These ferries run over 10 solar boats in India for the Asian market. hours daily and 350 days in a year. AltEn, after extensive R&D over 20 years, has patented many core technologies needed NavAlt Solar and Electric Boats Pvt. Ltd. for building a high...