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It's quick, it's quiet, and it's covered in 300 square meters (3,229 sq ft) of solar panels. The 78-ft (24-m) electric SolarImpact yacht is a concept designed as the first of its kind – an ocean-going solar-powered yacht. An 800-kWh battery on board gives it 10 hours of cruising capability, which can be extended by topping up the battery when the Sun's shining.
The yacht's giant solar array, which covers the vast majority of its upward-facing surfaces, can generate up to 320 kWh a day if they're getting lots of sun. They can serve as the vessel's sole power source if conditions allow, and you're prepared to take your time.
Although this 70-ton aluminum-hulled beast boasts 1,000 kW (1,341 hp) of all-electric power and has an impressive maximum speed of 22 knots, if you're running all the regular systems solely on solar, you will be able to cruise indefinitely, but only at a slow 5 knots – which would take you around the world in about six months if there wasn't a whole lot of land in the way.
Sea-steaders, rejoice!
(Score: 2) by hemocyanin on Thursday September 20 2018, @02:02AM (2 children)
The solar cells are there for backup. I never realized the amount of energy it takes to run a boat until I started looking at buying one and it really hit home when I started using it a lot -- I have a power boat for fishing -- nothing fancy or even that big (it's only 26') but when I do the math comparing fuel used to distance traveled, I get 1.75 MPG. The decimal is in the correct position. The most inefficient gas guzzling car gets something like 10x the distance on a gallon of gas as I do in my boat.
I have an older Leaf and I love it, but I think it will be a long time before battery the energy density required for boats is available for even full displacement hulls like sailboats (why not just use the sails??) or trawlers, and way off beyond my death for planing hulls.
Secondly, being able to apply power only a few hours per day is fine if you either assume perfect conditions or barely ever leave the dock. For example, if you can go 4 knots, three hours of juice will take you 12 nautical miles. If you cruise out 6 NM and then the weather changes so you are fighting a headwind that saps 1 knot of speed, you are going to find your batteries dry at 4.5 NM, or 1.5 NM from your dock or anchorage. That's a problem in a boat.
(Score: 3, Informative) by suburbanitemediocrity on Thursday September 20 2018, @09:35AM
A small 15m yacht with dual 455HP engines to push you to 30kts cruising speed is 670kw!
(Score: 2) by JoeMerchant on Friday September 21 2018, @02:21AM
It's definitely not super-practical. These "efficient" cruising speeds can barely make headway in the local tidal river against the current (current runs around 3.5knots normally...)
The "convert your boat to electric" electric motor sellers make claims like 20kW electric motor equivalent to 40hp diesel, and in some ways it is, but not in the "there's a storm coming and I need to get back to the dock NOW" way. Just like in cars, batteries weigh more than fuel tanks and IC engines put together, and while electric motors with sufficient power are available, they're not cheap, so lots of electric solutions end up underpowered due to cost considerations, and seriously under-ranged for the same.
I just recently ran a scenario past an electric conversion company: occasional 30 mile cruise in the inland waterway, their suggestion: add a (fuel burning) generator to the system to extend range, and cruise at 1/2 hull speed (aka 3.5 knots) to conserve energy.
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