Solar-powered boat MS Turanor won't win many races, but contributes zero carbon emissions. PlanetSolar

Lots of boats come and go in New York Harbor each day, but one catamaran in particular is attracting some stares from passersby, thanks to the 5,554 square feet of solar panels spackled on its upper deck.

The MS Turanor PlanetSolar, which is moored in Battery Park City for the next few days, looks like a flattened spearhead on skis, though a representative from the Swiss Consulate General compared it to a “grasshopper on the ocean.” The boat was originally dreamed up by a Swiss adventurer named Raphael Domjan and German businessman Immo Stroher, is sponsored in part by the Swiss government and has the honor of being the largest completely solar-powered sea vessel in the world. (Appropriately enough, the name Turanor comes from “Lord of the Rings” author J.R.R. Tolkien’s invented Elvish language Sindarin; “tur” means “power” and “anor” means “sun”). It's already circumnavigated the globe before, visiting 28 countries on a trip from September 2010 to May 2012. While in its berth, PlanetSolar keeps its wings folded slightly, but out at sea, the sides of the top deck fan out to expose its full complement of solar panels to drink in the rays.

PlanetSolar isn’t going to break any speed records. Out at sea, it averages a bit under 6 miles per hour, with an attainable top speed of a little over 16 miles per hour. The boat also lacks air conditioning – a feature that a group of New York journalists was quick to grouse about on a sweltering June morning on Tuesday. But PlanetSolar requires no gasoline and puts out no carbon dioxide emissions, which has some advantages, both for the environment and for scientific experimentation.

University of Geneva climatologist Martin Beniston is supervising a scientific expedition aboard the vessel called the PlanetSolar DeepWater mission. The craft has been tracking the powerful Atlantic ocean current known as the Gulf Stream since moving along the U.S. East Coast. After its New York City pit stop, PlanetSolar will be dropping into Boston, St-John’s, Canada, and Reykjavik, Iceland, before coming into port in Sweden. Along the way, researchers on Beniston’s team will be examining the characteristics of seawater, phytoplankton, and suspended particles in the air, all to get a better picture of how the atmosphere and the ocean interact and influence climate.

And because the research is taking place on a completely solar-powered vessel, “we can be near 100 percent certain that the aerosols [suspended particles] we capture are natural,” Beniston said. On other powered ships, the exhaust fumes from the boat are likely to contaminate air samples.

On cloudy days, PlanetSolar can rely on stored power to keep going forward – the nine tons of batteries stowed in the boat’s floats can hold a 72-hour charge. The ship’s captain, Gerard d’Aboville, closely monitors meteorological reports to manage his resources. If he sees that the boat will pass through a large cloudy area, he’ll cut the speed several days beforehand.

D’Aboville noted that the boat isn’t especially fast (though he’s crossed oceans in far slower craft – d’Aboville crossed the Atlantic Ocean in a rowboat in 1980, and rowed himself across the Pacific in 1991). The slowness is due in part to the fact that PlanetSolar weighs about 90 tons.

“It could be 30 tons, but then we could not have passengers, and it would be a prototype,” d’Aboville said.

So how long before the vast container ships across the globe are decked out with solar panels? It still seems a long way off. The captain “would not dare to say” that large shipping containers could trade in their diesel engines for solar energy in the near future. “It is not even a dream today.”

But PlanetSolar is still an important ambassador of solar power, d’Aboville said – a good way to test the waters. In July, Switzerland will be sending another solar ambassador to New York, when the completely sun-powered Solar Impulse plane touches down at JFK airport.