Fun in the Sun: Bringing Sail Wings Back to Greece

By Paul Gipe

I receive a fair amount of mail of the “What do you think of this” variety. Often it’s a quick push of the delete key and I am off about my business. Occasionally I’ve been known to go “Hmm” and forced to go a little further. A proposal by SAILWIND from the Hochschule für Technik, Wirtschaft und Gestaltung, Konstanz (the University of Applied Sciences, Constance) falls into the latter category.

Sail wings have fascinated wind engineers for decades. Frank Eldridge’s influential 1975 book Wind Machines described them as “modern descendent[s] of “jib-sail” rotors.[1] He starts his book with an image of the Smith-Putnam turbine counter posed with an image of a windmill on the Greek island of Mykonos.

That image stuck with me as did a later image of the Lasithi Plateau, the “valley of 10,000 windmills” on the island of Crete. As a result, I’ve long-called sail windmills “Cretan” after that photo though the jib-sail was used throughout the Mediterranean not just in Greece.

It’s the simplicity of the sails and their use of natural materials that intrigued me then as it has others since. After all, the Cretan sail windmill had been used successfully for centuries. It served its purpose well.

I remember stumbling across one at a London exhibition hall in 1976. There it was, a modern adaptation hanging from the ceiling as a focus of the exhibition on “alternative energy.” Developed by the Centre for Alternative Technologies—widely known as CAT—to generate electricity on a hillside in Wales. Soon I would dutifully make my first of several pilgrimages to Machynlleth.

Sometime in the 90s, Nancy and I explored an open air museum in the southern part of the Lüneburger Heide or heathlands south of Hamburg. The first thing we noticed on entering the Internationales Mühlenmuseum Gifhorn was the recreation of a Greek sail windmill with whitewashed stucco.

The museum promotes the sail windmill as a prominent feature on its web site still to this day. It would certainly seem exotic to a Northern European. On a cold, wet day what German wouldn’t long for the sun and warm breezes of a Greek island with a windmill gently turning, creaking and groaning like an old man.

And that is how the University of Applied Sciences in Constance, on Bodensee in German, its faculty and its students became enamored of revitalizing the hundreds of Greek windmills that are still standing.

While vacationing on the island of Santorini, famed for its bright whitewashed walls, domed churces, and deep blue sky, Professor Dieter Schwechten noticed that there were no modern wind turbines or solar farms. The island, blessed with wind and sun, relies on diesel to power the island’s tourist industry. The problem, Schwechten found, was that local authorities didn’t want to use modern technology that might detract from their appeal to international visitors as a vacation get-away.

With local hotelier Agapios Skopelitis, Schwechten dreamed of adapting the windmills that are prominent on the island to generating electricity. They would do this by incorporating modern technology for reefing the sails that were previously furled by hand. Thus was born Sailwind.

To say this would be challenging is an understatement. It’s an enormous technical challenge to make such a design work reliably, safely, and at low cost. The cultural and political challenges are also daunting.

I can easily imagine the authorities who don’t like modern wind turbines making the same arguments against restoring “historic” windmills. After all, the mills have been idle for decades. They’re now only props for tourist brochures. The windmills will be noisy, they’ll say. The mills will be dangerous too with all that spinning fabric, they’ll add, and on, and on. The same litany of pseudo arguments we’ve heard for years.

Of course, it could be simpler to just fly the authorities to a German tourist hot spot like Husum on the west coast of the Jutland peninsula and let them see for themselves that tourism still flourishes there despite the thousands of wind turbines in the region. Better yet, take them to the Spain’s Canary Islands. The islands are more akin to the Greek isles than the “gray city by the sea” and they too have hundreds of modern wind turbines, and probably solar farms as well.

The proponents are not naive. They know their proposal won’t solve the energy problems of Greece or its islands alone. They do think their concept can be part of the solution by harmoniously integrating modern technology into the communities through existing structures that have been accepted for centuries. And engineering students need challenging projects to hone their skills. Restoring a sail windmill with modern technology is certainly more productive than designing another ducted wind turbine or an off-beat vertical-axis wind turbine. Like most with an idea they believe in, Sailwind is looking for money to build a prototype.

I wish them luck.

[1] Eldridge, Frank R. “Wind Machines, Mitre Corp.” NS F RANN-75-051, 1975, 77. The Mykonos windmill is on page 9, the Valley of Lasithi’s 10,000 windmills on page 35, and Princeton’s sailwing wind turbine on page 21.