The energy is not free, since the solar panels cost money and don't last forever. Even at optimistic prices, it's still something like 0.03 USD/kWh. Install them on a boat and they have to deal with constant vibrations, humid conditions, seagulls shitting all over them, etc etc etc.
I used to work on ships and almost everything constantly breaks down without constant maintenance. I bet it would be much cheaper to put the solar panels on land and charge the ship when it's in port.
That may all be true, but there are other benefits that could make it worth it. For example it could be, in theory, self-sufficient forever if something else breaks down making it unable to maneuver. Then you can at least sit in the middle of the sea and have your heating and cooking and desalination working until you repair the propulsion.
There’s something funny to me about taking your experience with solar on a small sailboat and extrapolating this to a commercial ferry that would need a very large solar installation that’s funny to me. Something tells me the experience isn’t transferable.
The point isn’t to power the main drive, the point is to preserve energy used elsewhere on the ship.
My experience sailing and dealing with vessels from 30ft to 180ft give me a perspective that you probably don’t.
Providing solar panels along the roof would give the ship a few KWh of power that would otherwise be drawing from the main batteries. This would extend the range of the ship by 5-10%.
The ship battery is 40,000 kwh and uses at least 10,000 kwh per crossing, with 10 minutes to recharge. A handful of kwh are negligible because this isn't a sailboat.
The electricity sector in Uruguay has 98% renewable power
For how much cost? The range of the ship is already handled well by the batteries. An extra 5-10% isn’t going to meaningfully add value nor reduce fuel costs. There’s no way to recapture the capital expenditure such solar panels would require.
The 5-10% number is completely invented. I doubt it's half as high as 5%, but until and unless someone does the maths, there's no point in speculating.
The math has been done many times for solar panels on the roof of cars, and it's not worthwhile. Ships are not the same though.
At any rate, it's inevitably far more sensible to put a larger solar panel + battery installation at a fixed place on land, and charge vehicles from that.
The journey it makes is 90 minutes and it can charge for that journey in 8 minutes. Offloading and onloading the thousands of passengers (and 220 cars!) takes much longer than the 8 minutes for the battery to charge.
I wouldn’t go that far. Not at hull speed. But a good fraction of it. The silent 60 for example.
Full throttle you’ll be out of juice in a week. Hull speed maybe a month. Depending on wave conditions. But going, stopping, having lunch, enjoying the day, going again, enjoying tomorrow, you can be out there as long as you have provisions.
It is big difference between mounting solar on your personal sailboat and installing them on a large commercial passenger ship. The regulations are totally different.
Oh you mean like the Aptera or the Hyundai Ioniq 5? They do have solar panels built in. Prius Prime as well. These aren’t powerful enough to charge the main drive though, not enough surface area and voltage.
The Aptera vehicle is vapourware and likely always will be. It's not a practical vehicle that is on sale.
Solar roof on Ioniq 5 and Prius is an option, not standard. And it's rare. In fact, I've never seen it or even heard of it until I looked up what you were saying. And for the Ioniq 5 solar roof, it seems that it's not even offered at all in some countries.
The Prius one is "Offered as an option on the range-topping XSE Premium trim". Far from standard. This roof literally adds up to 4 of miles of range on a good day. (1) So it's a high-end gimmick that has niche use at best on a car, when compared to a fixed solar / battery installation situated where the car is parked.
The Aptera has been in development since the 90s and still hasn't shipped. The Ioniq 5’s solar option is a total gimmick - the panels capture a negligible amount of energy. Literally months of perfect sunlight to charge the battery. Nobody is producing solar vehicles at any scale.
I see many Hyundai Ioniq 5s on the roads in London UK. Exactly 0 of them have a solar roof - it's not even offered as an option here. It's a gimmick and there's no demand for it.
But why not put it on a Tesla if it will be so much more efficient than putting the same panels on your roof of your house and charge your Tesla with that?
Because they want to sell you the cheapest car possible for the most money possible, sell you a home charging unit, sell you solar shingles, sell you a new power plant for your home to go with those shingles. They are not in the business of making their cars efficient, only making the cash flow efficient.
> sell you a home charging unit, sell you solar shingles, sell you a new power plant for your home to go with those shingles
I don’t think you’re listening. This entire argument would lead to there being an expensive solar option for Teslas. There isn’t. It’s a terrible idea because the yield is bad. Solar panels are big flat panels that point at the sun. Cars are made of curved shapes.
This guy's impractical homebrew rig gets "20 to 30 miles per day" when unfolded and the car is not in motion. That unfolding is necessary as there just isn't enough surface area on a car roof to make it worthwhile.
It's still far more practical to 5x or 10x the number of solar panels, mount them on a fixed structure like a house roof, where they never have to be folded or moved around, and park the car next to it, to charge.
the fact that many new electric cars do have solar panels, I fail to see your reasoning. A solar panel isn't going to provide you with enough energy to drive. Merely enough energy to trickle charge your batteries.
Now, should you run out of charge during your drive, you simply have to wait a while and you'll have enough to get you to a charging station. Or you can walk, taxi there. On an ocean or channel crossing, you don't have that luxury and must rely on other ships if you run out of charge. The point I'm making is that any electric vehicle should incorporate solar panels into the design to minimize it's dependence entirely on the batteries and can extend it's time doing what it's designed to do.
As solar panels advance and the wattage increases, this will be more and more important as it will open up new avenues for transportation. Like the solar LSA plane "Solar Impulse" that can fly indefinitely.
> the fact that many new electric cars do have solar panels
Not true. Not many at all, in fact vanishingly few. I don't know of any EV currently on sale where it is standard. Because it's not practical. See comment above.
> Now, should you run out of charge during your drive, you simply have to wait a while and you'll have enough to get you to a charging station
Or not, as it adds a few miles of range per day of charging. You're far better off using the V2L capability of another EV to bring the charge to you.
> As solar panels advance and the wattage increases, this will be more and more important
No, it won't. Even at perfect panel efficiency , there just isn't enough room on a car roof to charge a car in reasonable time. Solar panel improvements won't do it.
> Like the solar LSA plane "Solar Impulse" that can fly indefinitely.
You can already drive an EV indefinitely, by mounting a much larger surface area
of solar panels on your house, and charging your car from that regularly, with or without an intermediate battery that allows you to charge the car overnight. This is proven and practical, unlike solar panels on the car. For solar panels on a car, the math is that it just never will be practical.
At least capture some of that to charge some batteries or extend the length of your voyage.