With the successful circumnavigation by Solar Impulse 2 , it is clear that photovoltaics are ready. If we can fly around the world, what else can we do? We can boat across oceans!
Clearly the time has come for this, because there are at least two hobby-grade solar boats going this year, and a professional grade. Of course, we’ve had solar powered toys, and conventional watercraft have used solar generators for years. But this batch is (a) entirely solar powered and (b) crewless. They also use a bunch of now ubiquitous technology.
One group is cruising the Pacific with a small robotic unmanned boat. The Seacharger has reached Hawaii from California, and is now on the way to New Zeeland.
Another group has dispatched the Solar Voyager to cross the Atlantic from Massachusetts. Solar Voyager is a small robotic Kayak, which should reach Europe by the end of the year.
On a more professional scale (though partly funded by megawealthy enthusiast Wendy Schmidt), NOAA’s Pacific Marine Environment Lab is operating two unmanned, sail powered, “Saildrone” craft in the Bering straight. These research vessels have no humans aboard, but carry a payload of solar powered scientific instruments to collect detailed data from a hard to reach region of the ocean.
I suspect there are plenty more project likes these, though not too many attempting open ocean navigation. The technology is here, and not just solid photovoltaics and batteries for power.
These robots use GPS to navigate (using Arduinos and other readily available digital tech), which is really cheap and easy now. (You phone does it, so anything larger than that surely can.) Actually, navigation at sea isn’t terribly difficult if you have GPS, everything is pretty much long straight arcs.
They are remotely monitored and, when necessary, commanded via satellite. In fact, I think they all use Iridium, which has global coverage, for pennies a minute. (I thought Iridium was dead, but apparently not.) These drones can be remotely operated just like your toy quadcopter, with very similar software. (But at something like 30 cents per short phone call, you want the boat to be pretty much self driving.
Another shared technology is gopro-like cameras and “track our progress on the web” pages, though the implementations could use some work on the latter. Still, we now expect to be able to sit at home in our armchair and follow solar powered drones from everywhere. (By the way, this use case is actually was something we were thinking of when we were booting up the Internet.)
In short, it is very clear that there is a critical mass of communication and computational technology and photovoltaics and batteries, that together puts sophisticated autonomous boats within the reach of hobbyists and scientists. Cool.
I’m not sure these boats are doing anything particularly valuable. Even the PMEL Saildrone data is pretty limited. It’s kind of like having a moving research buoy, which gives a bit more coverage than static buoys, but it is still very tiny on the scale of the ocean. They will need thousands of them to get much useful science, and who knows how feasible that will be.
The good news is that with no petroleum-based propulsion or people on board, these boats are fairly benign. They may not do any good, but they aren’t doing much harm. They are also small and quiet, so they don’t disturb the native animals too much.