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Written and Contributed by

NavAlt Solar & Electric Boats Private Limited
Kochi, Kerala


ADITYA – India’s first solar ferry which redefined the inland water transportation across the country is now celebrating 3 years of its successful voyage. Besides India’s first solar ferry, it is the first in the world to get more than 70% of its energy requirements fulfilled from solar. It has a seating capacity of 75 passengers and on a bright sunny day can cruise for more than 6 hours without the need for an external charge.

What is the project about?

The State Water Transport Department (SWTD) of Kerala operates about 100 ferry boats of different sizes from 75 to 100 passengers all over the state. They were all single-hulled boats, either made of wood or steel and powered by a diesel engine. Around 2013, they were facing a big issue.

It was not the pressing issue of air and water pollution, the noise and vibration from the engine making the ride tiring for the passengers, but the operating cost of the boats.

A typical ferry boat operating across the backwater in Vaikom-Thavanakkadavu sector, a distance of 2.8 km, with a ticket price of only INR 4 for the journey, generates about 5,000 daily in revenue. However, just its energy cost for 100 litres of diesel was higher than this figure (about INR 6,041). The direct cost of energy and maintenance is INR INR 6,645 /day.

In this context, SWTD was looking for a solution using solar energy to solve this problem.

We accepted the challenge.

Three things were needed to make solar ferry work.

Firstly, the weight of the boat needed to be around 17 tonnes compared to 35 tonnes for typical diesel ferries.

Secondly, along with weight reduction, the underwater shape was needed to be optimised to reduce the drag significantly so that just 20 kW motor power is needed instead of 60 kW for diesel ferries to run at 6 knots with 75 people on board.

Thirdly, the power train, consisting of lithium batteries, controllers, motors need to be rugged, reliable and marine grade.

After a year of design, six months of mould making, fifteen months of construction and three months of tests, a total of three years, ADITYA, India’s first solar ferry, was inaugurated on 12 January 2017.

ADITYA is a catamaran ferry boat with GRP (Glass Reinforced Plastic also known as FRP (Fibre Reinforced Plastic) hull and aluminium superstructure build under IR class (Indian Register of Shipping, a member of International Association of Classification Societies).

The boat has two energy and power train from the solar array, charge controller, battery bank, motor controller, motor, thrust bearing, stern gear, propeller. These are electrically isolated so that an issue in one system does not affect the other.

Apart from this, each motor is overpowered by 100% so that there is excess power available in need of emergency, high water current, or strong wind.

Compared to the current diesel ferry boat, solar ferry boats save 35,000 litres of diesel annually and reduces carbon emission by 94 tonnes of CO2 every year.

Project Funded by

The working capital for the construction of the boat was managed by Navalt self-funding and milestone payments by the Kerala State Water Transport Department as eventual owners of the boat.

Stakeholders Involved

Kerala State Water Transport Department, operational under the Government of Kerala is the owner of India’s First Solar Ferry – Aditya. KSWTD took the courageous decision to introduce an indigenized solar ferry concept in India which was then available only in European countries.

Department of Ship Technology, Cochin University of Science and Technology (CUSAT) conducted the feasibility study and was a part of the technical committee along with experts from Agency for Non-Conventional Energy and Rural Technology – Anert (MNRE state nodal agency), SWTD, Electrical Engineering and Polymer science departments of CUSAT for evaluating the design and construction.

NavAlt Solar & Electric Boats bagged the order for design and construction and launched India’s First Solar ferry in 2017. We received support from all segments including passengers, the general public, media, Kerala startup ecosystem in our journey all these years. 

What is the impact?

India’s first solar ferry which redefined the inland water transportation across the country is now celebrating 3 years of its successful voyage. In the last 3 years, Aditya had carried over 10 lakhs passengers without a drop of fuel-saving 75 lakhs Indian rupees (OPEX) and avoiding 280 tons of CO2. Break-even is achieved in the last 3 years (considering the operational cost and fuel cost saved) and from this year onwards ADITYA is completely profitable. 

Now the ferry is titled with the prestigious Gustave award as the world’s best electric ferry and is officially announced as an efficient solution that protects the environment in a profitable way by Solar Impulse Foundation.

Images by NavAlt Solar & Electric Boats | © all rights reserved

Links to read more:

A link to the project.

About NavAlt Solar & Electric Boats:

Established in the year 2013, NavAlt Solar & Electric Boats Pvt. Ltd is formed in line with the Make in India campaign. Two French firms, Alt. En and EVE Systems are investing in India to make economic solar-powered ferries. NavAlt aims to offer the benefits of solar ferries in India at one third the price of similar ferries in Europe.

Combining the technological innovation of Alt.En (France) with the design expertise of Navgathi Marine Design & Constructions (India), NavAlt will provide boating industry, more efficient and environment-friendly alternative to conventional ferries and cruise boats.

Our complementary strengths ensure that the clients get the best deal in term of quality and price. With the combined experience of Navgathi and Alt. En, NavAlt is the only entity in the world with experience of building over seventeen large solar ferries from 30 to 150 passenger capacity.

The customer support offered during the whole life span of the vessel and the strong will to change the boating industry to eco-friendly one makes us differen