March 1, 2011 - solar ships

For millennia, humans have used renewable energy to propel ships over the oceans.  The winds that have filled the sails of hundreds of generations' most technologically advanced vessels gained their power from the Sun's radiation shining on land and sea, creating temperature differentials that in turn caused the winds to blow.  Archaeological evidence suggests that the first sailboats may have been used by the Egyptians over 6,000 years ago.  Sail technology may have arisen in multiple separate regions of the world over time, but whoever was responsible for the first sailboats clearly started something big: harnessing renewable energy to move people and cargo over the water.

Photo: winter in Northeast Harbor, Mount Desert Island, Maine.

 Sailcraft still ply the world's waters of course, though the development of commercially-viable steam engines in the 18th century significantly changed the course of ship design and technology.  Naval engineers and marine architects continue to make advances in sailcraft design, using new materials and new design tools to create faster and more efficient vessels.  At the same time, a new kind of renewable propulsion system is arising: solar-powered ships.

As you read this, the 100-foot MS Turanor PlanetSolar has crossed the Atlantic, traversed the Panama Canal, and is well under way across the Pacific in its bid to be the first solar-powered vessel to circumnavigate the globe.  Constructed by Knierim Yacht Club, in Kiel, Germany, the PlanetSolar uses 537 m² of solar PV panels to generate up to 93.5 kW of power - about 125 hp.  The solar PV panels have an efficiency of 18.8%, and are linked to six 388-volt lithium ion batteries with an aggregate storage capacity of 2910 amp-hours (Ah).  (Compare the current Toyota Prius hybrid drive battery, which has a nominal capacity of 6 Ah.)

June 8, 2010 - tidal power in history: Winnegance to Passamaquoddy

I was fortunate to use wind power yesterday afternoon: I went sailing with a colleague on his Hunter 41. While on my way to the dock in Falmouth, I stopped by the site of a historic tide mill:

From Energy Policy Update

This isn't the best photo, but beyond the picnic table, you can see a stone pier extending across the mouth of Mill Creek. It seems information on the history of this mill site is limited, but it is suggested that it milled grain, and then lumber. The Town of Falmouth maintains a short but nice trail here, although parking is very limited.

In 1935, President Franklin Delano Roosevelt created the Federal Writers' Project, a program under the WPA designed to put writers to work while promoting economic development through tourism and industry. The project published 48 state guides to America (plus Alaska, Puerto Rico and Washington, D.C.) known as the American Guide Series. Each state in this series compiled its own detailed histories and descriptions of every city and town, along with narratives of interesting automobile tours.

Yesterday, I looked at the history of tidal power development at Winnegance, near Bath and Phippsburg, Maine. The 1937 Maine Writers' Project Guide describes the one remaining tide mill at Winnegance:

At 3 m. is the junction with a dirt road. Left on this road to a Tide Mill, 0.4 m., which until 1935 was used for cutting lumber. This old structure is a primitive forerunner of the mills and factories planned as part of the Passamquoddy Power Project.

So we can see that by 1937, policymakers including the federal government were reconsidering Maine's tidal power resources. Winnegance's tide mills were just on their way out, but the Passamaquoddy Power Project was just on the eastern horizon. Tomorrow I'll look at the 500 MW PPP in more depth.