Solar-Powered Engines ?

[simonpickard]

Hello all,

It'll be a few years yet before I can even think about the Cruising life but I'm loving this forum as it's great to soak up all the joint knowledge here.

One thing I've seen recently is a guy who swapped his Diesel engine for an electric one.
Got me thinking.. Are we at a place where tech allows us to power an engine via Solar panels / wind? The advantages of this seem massive if it's doable?

Tried a few searches but not nothing back really. Has anyone done this? Is it possible?

Just think... No more fuel costs.

Regards,
Simon

[sdowney717]

like this one?
Island Pilot DSe Home Page

Discovery Channel’s HD Theater recently featured the DSe on episode #9 of “World’s Most Expensive Rides.” Check your cable guide for reruns.

GREEN Tech is neither cheap nor green

[familycruisers]

Battery tech is getting there, like some of the lithium ion. They are light relative to amount of stored energy, but can be highly combustable when punctured or over charged.

[pillum]

Not possible with the present technology Simon. You never really know what's around the corner, but unlikely in the future unless there are some battery/photovoltaic technologies not yet invented. Even assuming you could cover the total deck area of a 40' boat with PV cells, you'd still have only have around 400 sq ft of cells, at an average of 12W/sq ft - 4,800W. If you assume a 70% light factor and a 90% power conversion efficiency this will leave you with only around 3kW of motor thrust, that's about 4HP. A forty foot boat would need 40HP.

[Bash]

Originally Posted by simonpickard

Just think... No more fuel costs.

There already is a technology whereby a boat can be propelled through the water without the consumption of fossil fuel.

It's called a sail.

[simonpickard]

Good point about the sails!
I guess my point was if this could be used WITH sails?
So charge up the batteries while you're sailing, and use an electric motor when needed?

Then it becomes an issue of how much battery power you have no?
If you replaced your fuel tank with batteries would that be close? Or am I dreaming?

Regards,
Simon

[Rhapsody-NS27]

There's probably a few companies that have electric motors. Click here to see one example. You can do a search on this site and find other threads. It's been discussed about the charging and how to set up and pros/cons.

[donradcliffe]

This group used a combination of solar powered electric and sail propulsion to move 6 big double canoes across the Pacific. They have a range of about 10-12 miles on a charge, which is enough to get them into and out of harbors.

The Vaka - Pacific Voyagers

[sdowney717]

all currently buyable solar cells will become obsolete when nantenna cells become available
Nantenna to Improve Solar Capture Threefold - Domestic Fuel

One of the drawbacks with solar energy is they only collect, on average, 20 percent of available sunlight. To address this problem, University of Missouri engineer Patrick Pinhero, an associate professor in the MU Chemical Engineering Department, is developing a flexible solar sheet that will capture more than 90 percent sunlight. Pinhero notes that energy generated using traditional photovoltaic methods (PV) of solar collection are inefficient and neglects a large amount of available sunlight. His team has developed a thin, moldable sheet of small antennas called nantenna that can harvest heat from industrial processes and convert it into electricity. The idea is to extend this technology to a direct solar facing nantenna device that would, in essence, collect heat and sunlight.

who knows when but it is a very good idea.

“Our overall goal is to collect and utilize as much solar energy as is theoretically possible and bring it to the commercial market in an inexpensive package that is accessible to everyone,” Pinhero said. “If successful, this product will put us orders of magnitudes ahead of the current solar energy technologies we have available to us today.”

current cells are too expensive and too weak.
I am holding off doing anything solar until some reasonable tech is available like the nantenna solar heat cell.

[barnakiel]

Yes. But it will be a small engine, or else you need big panels/windgens. Then, unlike wind and sun system, a diesel engine can be started any time. Then, current batteries are huge and heavy. Then, the whole system (solar panels and windgens, cabling, regulators and chargers, batteries, the engine will be way more expensive than an equivalent combustible system. Also, it will take way more space.

But all the components are there and the electric option is very good for some applications - e.g. a small daysailer that needs the engine to leave from and enter into its slip or say return to the slip, should the wind untimely die.

Also, a genset / el engine option sounds very good in other applications.

b.

[Adamante]

Originally Posted by sdowney717

I am holding off doing anything solar until some reasonable tech is available like the nantenna solar heat cell.

Or if you don't feel like waiting, the MS Turanor is available for around $20M.

[skipmac]

The simplistic answer is yes, electric power recharged by solar panels is available now BUT limited max power so suitable mainly for under 40' monohulls AND very limited range unless you have a diesel electric generator to charge up.

You would have to put in a few thousand pounds of batteries to replace the energy in an average diesel fuel tank. There are some high tech, lighter weight battery alternatives but the cost is extremely high.

[PushingThePen]

Having a bit of experience with alternative energy systems, it is very possible to convert a boat to electric, since there are other charging sources besides just photovoltaic (solar).

One major boost is the small, high output, wind turbines. These are light weight, easy to mount and can be integrated to alternative energy systems.

One of the key factors of any system is banking the batteries, not simply connecting them all together. By using a multi-bank format, it limits backlash and optimizes energy output to the battered.

Another thing to keep in mind is the need to up the DC voltage, which will allow the use of a more efficient motor.

Remember, alternative energy comes in a lot of different shapes and sizes. They even have a solar fabric. Panels are the old standard. Along with this, there are different type of solar cells that have various degrees of efficiency and output. Mono-crystalline, poly-crystalline and thin-film are the big 3.

The secret to making an efficient package is integrating the various type to work effectively together.

As to the costs... A lot more on th front end, but a lot less over the life of the components.

A catamaran, sailboat would be the best option, but even a powerboat can be converted effectively.

[PushingThePen]

Also, keep in mind that converting a boat to alternative energy doesn't mean you have to have a boat that looks like you simply threw a bank of panels on top and called it good. Many of the technologies can be artful integrations. Another look is th electric engine is a LOT smaller. You would also remove fuel tanks, keeping a small one for a backup generator and the batteries, though heavy, can be situated in several convenient formats for weight distribution, along with sifting them to the outside for proper venting. Several simple, safe methods for this.

One of my goals is to make a completely alternative energy motoryacht, with guts.

[GordMay]

Originally Posted by PushingThePen

... One of the key factors of any system is banking the batteries, not simply connecting them all together. By using a multi-bank format, it limits backlash and optimizes energy output to the battered ...

What is "backlash"?
What is the difference between "banking" and interconnecting batteries?
How does "banking" optimize energy output (input?) to batteries?