Electric boats - history
Over 150 years the first trials with electric-powered boats were made in England and France, before the gasoline and diesel have even been invented. In 1880, the first electric outboard motor was developed but the "success story" of combustion engines began just after, and continued until recently.
With projects like "Sun21", "PlanetSolar" and "SolarImpulse", we proved now to the general public that solar technology and electric propulsion are no longer a dream but a reality. The increasingly stringent regulations for internal combustion engines (on both recreational craft and commercial vessels), coupled with a rising price of fossil fuels and a strong will for environmentally friendly technologies, the age of electric mobility has definitely begun.
Solar Boat - the technical elements & components
1. The solar radiation is converted into electrical energy by photovoltaic panels.
2. This electricity is stored in batteries (equivalent to the fuel tank).
3. An electric propulsion (equivalent to a combustion motor) uses electricity to drive the propeller that allows the ship's propulsion.
4. In case of heavy use and / or use during periods without sunshine, it is possible to charge the batteries at dockside, for example at night.
Optional:The surplus energy produced by photovoltaic panels, while the batteries are at full capacity (this is the case on sunny days if the boat is not used) can be re-injected into the grid, thereby transforming the ship into a production unit.
A hybrid kit can power the batteries through an on-board generator, this "range extender" makes the boat independent of its batteries.
Frequently Asked Questions
Reliability: Electric drives were used in the first half of the 19th century and ships like the Queen Mary 2 or submarines are equipped with it, so this is a known and proven technology ! An electric motor, unlike the combustion engine has very few moving parts and is therefore subject to far fewer constraints of use.
Security & certification: Our boats are licensed to transport passengers and many classification societies (Bureau Veritas, Germanischer Lloyd, RINA) have certified our units. The use of standard, maintenance-free lead battery, a known and proven technology for decades, ensures maximum safety, the proposed optional batteries (including lithium) are only purchased from reliable suppliers.
Autonomy: We size our battery packs in order to provide at least 8 hours at cruising speed in the absence of solar gain. This autonomy can be increased by adding a hybrid kit (optional).
Speed: Energy storage in batteries is relatively limited, especially compared with fossil fuel. To reach a commercially attractive autonomy, it is imperative to operate boats with hulls studied for their low resistance, ideally long and slender. Our boats whose length varies between 8.50m and 17m, reach cruising speeds of the order of 9-12 km / h. Maximum speeds are around 12-17km / h but involve a much higher energy consumption.
Energy source: The sun is the main supplier of energy, which is required both to operate the engine as well as the on-board consumers (lights, navigational instruments, sound system ...). Some customers are 100% self sufficient with solar power only; some others are charging the boat at grid during the night, for eg. in anticipation of a long journey with little sun the next day. Last, the hybrid kit provides power to the battery while running.
Target areas for solar powered boats: Although one of our units has crossed the Atlantic (sun21 Project in 2007), our core business is located on preserved water bodies that are of particular interest for a gentle navigation respectful of its surroundings: lakes, rivers & canals, ports & marina, coastal strips... Our crafts are suitable for navigation in both freshwater and sea, evidenced by our customers in the Mediterranean or on the English Channel.
Durability & Maintenance: We build our boats in fiberglass and composite whose life is of course based on the maintenance and usage (a horizon of 20-30 years is very realistic). The electric drive contains little or no wear parts and requires no lubricant. A yearly check is sufficient. Batteries have a lifespan of about 800 cycles (lead batteries), which translate into a change on average every 5 years for our customers; manufacturers of Lithium batteries announce about 2000 cycles of charge / discharge. Solar panels do not wear out and their performance are guaranteed at least 20 years.
Warranty: The boat's structure is guaranteed for 5 years, and components are warranted by their respective suppliers (at least 1 year).
Comparing the cost of operating a solar boat related to a diesel operated boat: On top of the "image aspects" (which results in an facilitated access to financial funds to acquire the boat as well as a draw for customers), the great advantage of the solar boat is that it replaces the cost of fuel by free solar energy that may be completed by a very modest charge from the grid (2-3 Euro as sufficient for a full charge providing 8 hours of navigation). The electric drives do not use lubricant and require almost no maintenance, unlike diesel motors. In terms of operating the boat, the immediate availability of an electric motor and its cleanliness drastically reduces the need for preheating and preparation, unavoidable on traditional units.
Photovoltaic panels: We chose to use mono crystalline panels. This choice is due to the excellent performance of these cells, enabling thus a significantly extended autonomy of the boat compared to polycrystalline or even amorphous cells.
The engines of our boats are sized to be the best compromise in terms of energy and powerful enough to allow the vessel's maneuverability in the different circumstances of navigation. Powers may seem relatively weak at first but be aware that an electric motor needs roughly only half of the power of a combustion engine for the same performance and thrust.
Current and expected progress: The acquisition costs of photovoltaic panels have dropped significantly and this trend should continue. In parallel, the performance of the panels keeps on improving as well (our recent installations use modules whose total return greater than 18%. On the battery front, the lithium technology now brings significant improvements in storage capacity, low weight and durability. The important work (and volumes) of electric-cars enable the boat to take advantage of these advances.