OK folks, this is the 21st century, with current technology don't you think it is time to add solar boating to the mix?
Good question. Here's a real long opinion....
Solar certainly has promise. The entire roof of our new 787 assembly building in Charleston, SC is covered with solar panels. I'm told that the power generated from them when fed back into the grid makes a major big dent in the power bill for operating the assembly plant, which as you can imagine uses a LOT of power.
So I think solar, like wind, makes sense where it makes sense. In Charleston, it's sunny most of the time and even in the winter the days are reasonably long. Not so in the PNW, BC, SE Alaska, etc. as Tom pointed out. So solar is not very common here other than some folks off the grid use it to heat hot water. For electricity they tend to use generators.
I do not see the problem so much as a technological one but a practical one. Moving a boat around of the type most boaters still want these days takes a lot of power. One or two gas or diesel engines worth of power. And most boaters, from what I've been able to gather, want to go fast. Or at least reasonably fast. While there are those who say they like going slow (8 knots or less) I think in the overall market of boats that are sold worldwide, they are a very tiny proportion of buyers or potential buyers.
People like to go fast. They want to get places NOW, they want to communicate NOW. My job takes me all over the world and everywhere we go--- China, Brazil, the UK, Norway, Malta--- people are trying to go faster. Trains, cars, planes, boats, you name it. The only thing that stops people from going faster is cost, safety, or a lack of technology.
For every slow cruising boat owner I know or have met, I know or have met many times more people who have bought Bayliners or Sea Rays or Grady-Whites or ski boats or bass boats or some sort of relatively go-fast production boat. And as I think Art and others have pointed out a few times, the interest in slow cruising boats seems to be dying out with the generations that have them today. The relatively few twenty, thirty, and forty-somethings I know who are interested in boats to fish or take their young families cruising in all yearn for fast ones.
There are huge billboards in China promoting new oceanside developments that include manmade lagoons and docks for keeping a boat outside your condo-type home. Alongside the development billboards are the billboards promoting the boats their market research has shown their potential buyers want to own. They ALL show fast, sleek boats--- Sea Rays are predominant along with other fast runabout or express-cruiser type boats. No billboards for 8 knot plodders.
Qatar, now the world's richest nation, has boat dealers alongside the Ferrari and Lamborghini dealers at their new massive oceanside development, The Pearl. And the boats in the marina? All fast cruisers or express cruisers. No "efficient" cruisers like Nordic Tugs or whatever. And no sailboats. Not one.
And you're not going to be running your friends and family around at 20-plus knots in a sleek, Ferrari-like boat that's 40 or 50 or 70 feet long that's solar powered.
In my department there are eight (I think) very active boat owners. Of the eight, I am the only one with a slow, "efficient" boat.
(I am also the oldest one... perhaps another "indicator" of some kind although as I have stated in the past I absolutely abhor going slow in a boat and my wife is the same way. The only reason we put up with it is because we so far aren't willing to spend on boating the money it would take for us to have a go-fast cruising boat. We have other things to spend it on that are more important to us right now.)
The other boaters in my department have various models of Bayliner cruisers and a couple of them own Tollycraft 26s, a gas-powered inboard, V-drive fast cruiser.
So while the go slow, use as little energy as possible boaters are definitely out there, I don't think they're out there in enough numbers to make solar powered boats viable EXCEPT to the very few who are interested enough in the challenge to tinker around and come up with something workable on their own. Workable, but not producible to a market large enough to make it producible.
I think solar is a long, long way from even beginning to compete with fossil fuels when it comes to cars, boats, planes, etc.. We keep discovering more petroleum and gas reserves or new, more efficient ways to produce more petroleum-based fuels.
It's certainly a tantalizing windmill to tilt at--- harnessing the zero cost of the sun's energy. And as I say, there are applications that make economic sense, like our assembly plant roof.
But as a practical, marketable, producible source of energy, particularly for individual transportation devices like vehicles, boats, planes, etc., I think there are better options. Fuel cells, for example. We (Boeing) flew a fuel-cell powered plane in Spain a couple of years ago. Total success. Now nobody in the industry is pretending that fuel cells are going to power the 7X7 in the future. But we have them flying on test planes (737) to power various systems on the plane, thus removing those loads from the engines which means the engines can operate more efficiently. It's still a long way from being a production reality, but it has promise.
I think solar boats can and do work, and for the tinkerer like deckofficer and others it's an interesting and challenging objective. But I think only on a one-off basis.
But in the big picture I believe there are energy sources "out there" that we have not even realized exist, nor do we have the knowledge yet to discover them let alone make use of them, that eventually will push petroleum and solar and wind and fuel cells into the past.
After all, the Egyptians could have built a 777 instead of piling up rocks into pyramids. All the principles of mathematics, physics, chemisty, aerodynamics, metalurgy, you name it, existed when they were mucking about with boulders. All the principles, theorems and formulas for mining bauxite and smelting it into aluminum and forming it into airplane skins and all the rest of it existed when the Egyptians were doing their thing with rocks and papyrus. They've existed since time or earth or Mind or Spirit or whatever you believe in, began. Two and two has always equalled four.
So I am otimistic that the future holds some amazing things that we cannot even conceive of even though we humans always tend to think that the time we are living in is the absolute ultimate, it can't get any better than this. The Egyptians certainly felt that way, and if you'd have told them that one day man would be flying around the world willy nilly and driving over the ground at 70 mph and communicating with each other using little handheld glass panels they'd have put you inside one of their big pile of rocks.
So.... I think solar is an interesting stop along the way and in some applications it can prove useful but I don't think it's going to be the be-all, end-all solution to our energy requirements. Its applications are too limited-- geographically let alone performance-wise--- and the "bang for the buck" in terms of energy for the investment does not seem to be there and I tend to think never will be. Something else will come along to push it aside.
As far as the forum is concerned I think the suggestion to create a "bucket" for the alternative energy enthusiasts is a good one. It's the kind of subject that the proponents tend to get very, very detaily about as they debate the pros and cons of this sort of solar cell or that one and how to wire them up and what motors are the best and so on. Interesting to them, not so much I suspect to the majority of participants on forums like this who want to know why their diesels are putting out white smoke.