Cape Cod windmills then and now

I've always loved windmills.  There's something about them that just makes me smile.  I think it may have something to do with the combination of engineering elegance, and architectural whimsy that they universally exhibit.  I like em all, from the old weather beaten Aeromotor out in Auntie Em's pasture, to the shingled mill tower so unjustly attacked by Don Quixote de la Mancha.  In some respect, my favorites are the businesslike acres of high tech spinning industry one finds in modern wind farms.  Certainly part of the appeal is the lure of getting something for nothing.  Using our minds to create a device to harness this insubstantial energy then stepping back and letting it do real work while we sit in the shade.  When we moved to Cape Cod in the mid 1990's, I was delighted to find that the salty breezes here have powered many a windmill over the span of history and they are still very much in the news today.  

The Past: Canvas & Shingles

The first windmill constructed on Cape Cod was built in 1687 at Cobb's Hill in Barnstable Village.  This eight sided smock-type mill was built by the millwright Thomas Paine of Eastham, Massachusetts who received 32£ for his efforts.  The success of Cobb's Hill mill quickly gave rise to many others and over the course of the next one hundred years over fifty of these statuesque beauties were spread over the Cape.  Nearly every town had at least one windmill to perform the essential task of grinding the harvest of grain.  The local mills also served a more social function as a gathering place where the townsfolk gathered to enjoy a chat while they waited for their grains to be ground.

Every successful windmill required the efforts of at least three talented individuals. First, there was the millwright, who constructed the windmill tower, a structure strong enough to withstand the fierce winter storms common to the Cape.  Next came the millstone picker, who was responsible for selecting and carving the millstones as well as maintaining them once they were in service.  Finally, the miller, often a retired sea captain, who ran the mill, adjusted it based on the wind conditions and repaired the many yards of its canvas sails.  Not so very different from a ship after all.

The smock-type windmills traditionally built on Cape Cod were a second generation improvement on the earlier post mills developed in Europe. Smock-type mills have a fixed tower housing the mill machinery,  and a "smock" or cap on top that rotates, allowing the blades and rotor to follow the wind. Typically the body of a smock-type mill is octagonal and tapers slightly inward as it rises above the ground.  Inside the tower were one or more sets of millstones used to grind the grain.  Millstones are typically thick granite disks about a meter in diameter and 40 centimeters thick with shallow grooves radiating out from the center.  The bottom stone is fixed in place and the top stone rotates above it, powered by the blades and rotor through a gearing system.  The distance between the top and the bottom stones could be adjusted, controlling the coarseness of the grind.  

You can still find many fine examples of these historical windmills throughout the Cape.  Lovingly restored windmills can be found in the towns of Bourne, Orleans, Chatham, Sandwich, Brewster and Eastham among others.  Some these are privately owned, while others, such as the Old Mill in Eastham are open to the public. 

The Future: Turbines and Megawatts

While the old shingled windmills spinning slowly in the sea breeze have a solid lock on our nostalgic daydreams, the imagination of modern cape codders has been captured by windmills of a very different type.  Cape Wind Associates, a private corporation proposes to put 130 high tech wind turbines on Horseshoe Shoal, five miles off the southern shore of Cape Cod.  Each wind turbine will stand 197 meters above sea level, and have three 50 meter blades.  The project will cover 25 square miles and a peak output will produce enough energy to power more than half a million homes, and save over a hundred million gallons of oil each year.  Cape Wind Associates anticipates spending over $150 million dollars on the project.

On the face of it, you might think that this would be a dream project for Cape Cod.  After all, it's clean, it's green and it would make a statement to the rest of the country that we are serious about exploring alternative sources of energy.  Unfortunately, the reality has been nearly so simple and the project is currently snarled in a nasty political tug of war.  

The unlikely list of project opponents includes:

The give and take of the argument is a fascinating study in the complexity of modern environmental politics and NIMBY-esque rhetoric.  Here are some representative examples:

Marine Mammals

Pro: The most common ocean mammals in Nantucket Sound are seals. Extensive studies of the Bockstigen wind farm off the shore of Sweden found no adverse impact to the abundant local seal population there. In fact, seals have been regularly observed sunning themselves on rocks near the Bockstigen wind farm and near the Tuno Knob wind farm off the shore of Denmark.

Con: Horseshoe Shoals is within 7 miles of Muskeget and 12.5 miles of Monomoy islands, which are important haul-out areas for more than 7,000 gray and harbor seals and pupping sites for gray seals.  Data indicate that harp, hooded, harbor, and gray seals are stranded regularly from Falmouth to Monomoy and are, therefore, likely transiting the area on a regular basis. Because of potential noise during construction, wildlife may abandon habitat, seals may abandon pups, and animals may experience potentially permanent hearing loss. 


Pro: When designed properly, wind turbines are much safer to birds than other sources of energy production. The nation’s reliance on fossil fuel energy has brought enormous harm to birds from oil spills, habitat destruction due to practices like “mountaintop removal” mining, and mercury contamination of the fish they eat.

Con: Horseshoe Shoals is in the middle of the Atlantic flyway with one of the largest known concentrations of waterfowl on the east coast.  As many as 250,000 to 500,000 birds are found here for at least six months of the year.  The endangered roseate tern and threatened piping plover are known to migrate through Nantucket Sound, as do thousands of other birds during their spring and fall migration.  It is critical that these species and their rich habitat are not adversely impacted by the construction of a windmill farm.

Navigational Hazards

Pro: Cape Wind does not seek exclusive use of Horseshoe Shoal. Access for boaters who use this shallow shoal will not change. The wind turbines will be spaced six-to-nine football fields apart to provide plenty of room for navigation. Cape Wind will be given permission to install wind turbines only if government agencies determine that, on balance, it is in the public interest to provide this clean, non-polluting electricity from this location in this manner. Cape Wind is undergoing a full, comprehensive and rigorous permitting review from federal, state and regional authorities. Numerous government authorities are involved in reviewing and approving various aspects of this project including: US Army Corps of Engineers, US Coast Guard, Federal Aviation Administration, Massachusetts Energy Facilities Siting Board, Massachusetts Executive Office of Environmental Affairs, Massachusetts office of Coastal Zone Management and the Cape Cod Commission.

Con: The Corps of Engineers is considering permitting this project under Section 10 of the Rivers and Harbors Act, which is designed to address hazards to navigation. This is insufficient for a project of this magnitude. Other activities that impact the marine environment, such as oil and gas exploration and development, are subject to laws requiring issuance of leases through a competitive process, and provide procedures for addressing environmental concerns and balancing project benefits against adverse impacts.  Until the proper process has been established to consider the impacts of windmill farms such as this project, we call for a halt to the issuance of permits for wind, wave, and other energy installations in federal waters.

Visual Impacts

Pro: From the shore, the slender supporting towers will blend in with the horizon making them nearly invisible on all but the clearest days. While many people who have seen modern wind turbines describe them as beautiful and fascinating to watch, we recognize that aesthetic values vary. The project’s location several miles away from shore will reduce the visual impact of the wind turbines. On clear days, they will appear like small masts on the horizon.

Con: The towers will not, as developers insist, "blend in with the marine landscape" unless they are installed under water. The horizon and miles of towers will be plainly visible from south-facing points on Cape Cod at or above sea level.

And on and on and on.  The long history of windmills on Cape Cod continues to this day. 

Look there, my friend Sancho Panza, where thirty or
more monstrous giants present themselves, all of whom
I mean to engage in battle and slay!

- Cervantes


Comprehensive Windmill Website:
Mechanical drawings of a Smock-type Windmill:
Cape Wind Associates:
PMMRC Windfarm Statement of Concern: 
Alliance to Protect Nantucket Sound: