The idea is to develop a boat that runs on a motor powered by batteries. No sails, just an engine-powered boat. Batteries would be continuously charged by solar panels/coverings and in-built hydrogenerators.
Do you have any comments, add-ons, or examples?
Can you think of any other efficient way to generate electricity on the boat without drastically affecting the speed?
I want to buy a boat and I would like it to be a smaller yacht (I don't like sailing).
I have two problems:
I have no money for the yacht and
I have no money for the fuel
Let's say that maybe sometimes in life I will have money to buy a middle-sized boat, so that solves the first problem. The second one remains and it's big. I found information that an average superyacht spends around 500 liters of fuel per hour just to run the engines and not moving the boat . While cruising, the costs grow up to 2500$ per hour. Although I would like something much smaller, the fuel costs are still pretty big.
What if we built a zero-energy boat that power itself? A perpetuum ship that could run for years without needing to stop to fuel up. The idea is to brainstorm and see could the energy generated from solar panels placed all over the ship, solar coverings of the boat sides and the hydrogenerators like this one be enough to power a battery that powers the electric motor.
What else could we add to enhance the energy production?
The idea is nice and attractive. It's definitely not novel per se, but it could have novelty in its DIY aspect. What you propose here is a money-saving, small option, almost along the lines of off-grid, self-reliant living. So maybe we could brainstorm how to approach making such a boat with the least finances. In that regard, it reminds me of many ideas/sessions that Darko has posted. So my suggestion would be to change the title to a DIY Perpetuum boat (just a suggestion).
Talking about technical aspects important thing here is the ratio between the size of the boat and the surface area of solar panels - the smaller the first one and the bigger the second, the easier it will be to make it run entirely on solar and the faster it could go. Look at this
- the surface area of the cells is crazy big (almost nothing else can be on the deck). On the other hand, the boat is also rather huge.
It will very much depend on what speed do you want to attain with that boat. A small boat that moves slowly should be no problem to power with solar cells (if you want to take your time to "sail" around the world, for example, while living on the boat), but if you want to be able to go rather fast, then, of course, it will be more difficult. I tried to research the physics of this a bit, but didn't manage to find the right formulas, thismight be of use.
Basically what's necessary is to calculate what size of the propeller(s) and power of the rotor(s) can move a ship of a certain mass. The maximum speed that you want to be able to achieve will define the upper limit of the rotor power. When you'll know the range of the rotor power, you can turn it into the range of the electric power that will be necessary to get from the solar cells and you'll know how many cells at what light intensity will be able to generate that power. So the mass of the ship, the surface area of the cells, the light intensity, and the power of the rotor(s) are the main factors to take into account. Oh, and the fact that electricity will be necessary for other things inside the boat is not to be forgotten.
So it will depend a lot on where you'll be sailing, what kind of weather it will happen to be, all that. If you want to be able to go non-stop (a real Perpetuum situation) then nighttime is a big problem. I don't think you can rely solely on the power gathered in the batteries during the day for this. Unless again you are ok with just drifting or moving very slow. To have a sail just for situations where there's not enough power from the cells seems like a good idea - a hybrid boat (also, most likely already existing).
Please leave the feedback on this
Solar-electric hybrid yacht with backup generator
salemandreusJul 11, 2021
The Silent Yacht 55 is branded as “Solar-powered and self-sustaining” in this review.
This article explains how was designed partly to address the exact problem you mentioned of conventional yachts consuming vast amounts of fuel even while idle. The creator “[researched] the best ways of harnessing renewable power aboard a cruising boat to keep the generator off. He weighed up wind, solar and hydrogenation [...] [saying] [...] ‘When we did the measurements, solar produced much more [than the other options].’”
-It has no engine, runs on two electric motors
-Can be powered by either:
An array of 10kw solar panels which allow for cruising in continuous sunlight.
A bank of 140kwh lithium batteries (on the older model mentioned in the above review) or 210kWh (newer model).
You can cruise using the battery bank from 2-12 hours (older model) before needing to recharge, depending on how much power you are using. These would be used when you don’t have direct sunlight powering the yacht or if you want more power.
100kw 600l diesel generator (admittedly this is diesel but far far more efficient usage of it than the superyacht!)
Hybrid of running on battery power while being charged by the generator
This is the most efficient usage of the diesel: When your battery gets low you can run on batteries with the generator charging them at the same time (this also kicks in automatically below a certain threshold so you don't have to worry about running out of power or having to start the generator up manually) and this hybrid running provides what This reviewer in 2019 describes as "pretty much continuous running" - and this was on the older model, before the battery upgrade. It then only runs at 50% power, which is optimal for charging the batteries and powering the generator.
According to the second link article about the older model, one user boasted about being in his second year generator-free on the yacht, as one would barely use the generator at all at lower cruising speeds of 5-6 knots. Although though if you are wanting high cruising speeds you will still have to use the generator some of the time so it seems there would be some trade-off between fully clean energy and speed.
The newer model with the 210kWh battery was reviewed here last year which had this to say about the yacht’s power usage and self-sustainability:
“With a 600-litre diesel capacity the generator’s tank will not need regular fills and there are no mechanicals to service apart from the generator itself so you need to carry very few spare components. You don’t depend on shore power either so if you genuinely want to live on board and get away from the crowded surroundings of a marina this boat delivers that.”
Some other notable perks of this model:
Mostly clean energy
Silent - all of the reviewers remarked on how silently it ran, one even titled the article "The Sound of Silence"!