Imagine My Surprise . . . . .

.... to discover that others had happened upon a similar idea for a wave energy conversion / floating platform stabiliser to one that I have played with for over ten years now. My inspiration came from reading the Marshall Savage book, The Millenial Project.The version above was conceived by Joseph George, and is described further here. The idea as pictured needs some modification to provide greater robustness in high seas, but the drawing demonstrates the function of one short row of the devices. In an actual floating platform, many such rows would exist, in arrays.

The next two images portray a similar device which helped win the Rolls-Royce Prize for best Master's Thesis in 2007, and the JEC Innovation Award in 2009. This prize winner is the result of a collaboration between Norwegian and Belgian engineers. As you can see, the "point absorbers" in the second platform converter are not open-bottomed like the absorbers in the Joseph George design at top.

The image above and to the right shows a "wave farm" comprising four of the platforms pictured below and to the left.
The platform design with multiple point absorbers presents advantages that are not available from several other wave energy conversion devices, particularly when incorporated into a seastead design.

The concept of using such point absorbers for both wave energy conversion and for "shock absorbers" to smoothe the platform's ride, appeals to my sense of multi-functionality. For rough seas in the open ocean, some form of "breakwater" would still be necessary to reduce the shock to the platform and the point absorbers.Looking at the most recent prototype design for a seastead from the Seasteading Institute, it is not terribly difficult to imagine the placement of similar point absorbers beneath the platform, given the suitable infrastructure. As I said, however, in high seas the occupants of such a seastead might be grateful to have a sturdy floating breakwater on the job. Al Fin engineers are in the process of designing such a "device."

I am pleased to see that the "point absorber" wave energy conversion idea has been developed to this point by multiple inventors, and hope that such platforms can eventually be used productively.

Daring to Cross the Waters By Pedal, Sun, Beer, and Wave, 69 Year Old Ken-Ichi Horie

First he pedaled a boat from Hawaii to Okinawa. Then he crossed the Pacific in a solar-powered boat. Next he soloed the Pacific in a catamaran built of beer kegs. Now, he plans to sail from Hawaii to Japan in a novel "wave-powered" boat--in slow motion.

This month, 69-year-old Japanese sailor Ken-ichi Horie will attempt to captain the world’s most advanced wave-powered boat 4,350 miles from Hawaii to Japan. If all goes as planned, he’ll set the first Guinness world record for the longest distance traveled by a wave-powered boat and, along the way, show off the greenest nautical propulsion system since the sail.

A simple spring system enables twin fins beneath the bow of the Suntory to move up and down with the incoming waves and pull the boat forward.
At the heart of the record-setting bid is the Suntory Mermaid II, a three-ton catamaran made of recycled aluminum alloy that turns wave energy into thrust. Two fins mounted side by side beneath the bow move up and down with the incoming waves and generate dolphin-like kicks that propel the boat forward. “Waves are a negative factor for a ship—they slow it down,” says Yutaka Terao, an engineering professor at Tokai University in Japan who designed the boat’s propulsion system. “But the Suntory can transform wave energy into propulsive power regardless of where the wave comes from.”___PopSci

How efficient is the wave-powered mechanism? At first glance, I would have to say "not very." A maximum speed of 5 knots means his journey will take at least 3 months. His electronics and communication will be powered by solar panels. He will also have an emergency outboard engine on board, just in case.

I like the idea of tapping into the wave energy of the sea, to drive a boat. As a proof of concept, it is not a bad adventure. Yet, waves are a tertiary solar effect, derived from a secondary solar effect--the wind. Somehow, I cannot help but think that there is a good reason why ancient seafarers chose sail over wave power for traveling long distances by sea.

Sustainable Ocean Living--Piece by Piece

Energy Islands are floating modular renewable energy platforms that incorporate photovoltaics, solar thermal towers, wave energy, ocean current energy turbines, wind turbines, and OTEC (ocean thermal energy conversion). Designed by architect Alex Michaelis, the concept is aimed at capturing a share of Richard Branson's Virgin Earth Prize.

Each island would be built on a floating platform and at its centre would be a plant that converts heat from the tropical sea into electricity and drinking water. Below deck would be marine turbines to harness energy from underwater currents and around the edge floating devices to provide wave power.

Vegetable farms and homes for workers will complete the colony and the power will be piped back to be used on the nearest populated land mass.

Michaelis, who is working together with his father Dominic, an engineer, estimates that each island complex could produce 250MW.

NextEnergy

Combining enough Energy Island modules to form the outside of a protected lagoon, you would be on your way to renewable power, agriculture, and aquaculture for your floating city.
Aquarius is the sea-colony concept from Marshall Savage, writer of The Millenial Project. Self-sufficient Aquarius floating cities would be the first step to colonising the galaxy. The lessons learned from building sustainable and profitable colony-cities-on-the-ocean could be transferred to floating cities in outer space.

A different group has coalesced around the concept of "Seasteads". For the seastead movement, building a sustainable floating city is an end in itself.

In the past, pioneers and malcontents would head to the frontiers, of which few now exist. The oceans, which make up 71% of the earth's surface, have always been a place for those seeking new ways of life. They are the last great unclaimed region. Ships are not well suited for permanent living, but by creating new land on the oceans we can achieve both freedom and a reasonable degree of comfort.

Freedom of movement and self-sufficiency are both intimately connected with political freedom. Fixed locations such as seamounts, islands, and atolls are much more vulnerable to the whims of nearby governments [minerva link], but a mobile seastead can always move if the political climate becomes unsuitable. While a seastead is likely to import many goods, being able to supply its own basic necessities will also add greatly to its independence. This approach to nation founding reduces - but does not eliminate - the difficulty in finding sovereignty, by operating in international waters...If the seastead is parked in area that does not get regular rain storms an alternative method of fresh water replenishment is needed. Either sea water distillation or reverse osmosis will work. Both forms of sea water reclamation require pretty hefty amounts of power. Distillation can be done with solar evaporation trays and condensers; whereas reverse osmosis runs off of electricity....

Seastead Book
Seascape One, pictured above, is a combination tourist destination and high-end condominiums designed to float around the Mediterranean Sea. It incorporates multiple renewable energy features, including wind and solar power. The tall white structure projecting above the living section is a solid sail, for clean (but slow) propulsion. Lessons learned from operating such a design should be applicable to a more rough weather seastead.
Paolo Soleri designed floating arcologies which could also be classified as "seasteads." The "Nexus" floating city project is more than a little based on a Soleri design.

This is a floating city designed to accommodate 100,000 persons. 7 kilometers long and 4 kilometers wide with the capacity to be mobile, grow its own food, produce its own electricity and, owing to it existing beyond the 12 mile governmental jurisdiction boundaries, create its own government, income system and tax base. In essence, this mobile city becomes its own independent country....The city utilizes several different types of electrical power generation. Five Ocean Thermal Energy Conversion units are positioned at strategic zones of the city to supply electricity. Banks of freestanding windmills and photovoltaic solar cells produce additional electricity. The "head" of the floating city is a small mountain range with a specially designed frontal structure that cuts Tsunami tidal waves into smaller, manageable waves with little destructive effect. It is a tidal wave barrier that requires the city to head into the on-coming wave. Nexus

The video above is a graphic portrayal of some of the aspects of the "Energy Island" concept--the UK project that wants a piece of the Virgin Prize.

Wave Power

Wave power is derived from solar energy--by way of the wind. It is a constant, 24 hour energy source, so unlike solar and wind, waves could potentially serve as baseload power. Several approaches to tapping ocean wave power have been tried, none particularly useful so far. One ongoing project off the California coast may merit attention.

Pacific Gas and Electric Company has announced that it has entered into a long-term, two megawatt (MW) commercial wave energy power purchasing agreement with Finavera Renewables Inc. Located off the Northern California coast, the Humboldt County Offshore Wave Energy Power Plant will be developed by Finavera Renewables. The project is expected to begin delivering renewable, clean electricity in 2012.

“Harnessing the ocean’s energy on a utility scale is a critical achievement in renewable energy technology and this project represents our first step in that direction,” said Fong Wan, vice president of Energy Procurement, PG&E....Finavera Renewables has initiated development plans for the two megawatt wave energy project to be constructed approximately 2.5 miles off the coast of Humboldt County, California

NextEnergy
One of more interesting proposals for transducing wave energy to electric power comes from SRI International.

The concept derives from the discovery a little over a decade ago of so-called dielectric elastomers, stretchy plastics that react to and generate electricity. When electricity runs through an elastomer, the elastomer compresses and contracts, much the way a muscle does. It didn’t take long for researchers at SRI International, a nonprofit organization based in Menlo Park, Calif., to realize that the process would work in reverse: stress and relax the elastomer, and it will generate electricity....Imagine a cable of elastomer with one end tied to the ocean bottom and the other attached to a buoy on the surface. When the buoy rides up a crest of the wave, it stretches the elastomer. When it sinks into a trough, it contracts and then generates a pulse of electricity.

NYTimes

So far, the energy generated is on the order of watts, not kilowatts. But SRI is not an organisation to give up too easily. In fact, a wide range of companies, corporations, and other organisations are vying to make wave power a viable commercial enterprise.

The UK Department of Trade and Industry projects that wave power could by 2025 produce 20% of the UKs power electric power demands.

Wave Energy Resource Links:

Wikipedia Wave Power
Peswicki Ocean Wave Energy Directory
Alternative Energy News: Wave Power
Wave Energy Centre Resources
Wave Power OCS White Paper

While nations with a large coastline, such as the UK, can profit from wave and offshore wind energy, the killer app for such energies is the "seastead". A floating island, well away from land, would be in an optimal position to exploit wave power, sea winds, and OTEC. The full energy repertoire of a large seastead would include ample PV, solar thermal, and possibly small scale nuclear.

A seastead is a seagoing version of a relatively self-sufficient city-state. As most regular Al Fin readers know, many trends in current events are leading toward an era when the city-state becomes important again in world affairs. Singapore is the best example of a contemporary city-state, although Hong Kong has the potential to be another, should the mainland communists lose their vampire's grip.

Most modern nation-states are entirely fossilized in their present form. Only a large catastrophe would lead to the disintegration of most western nation-states. Should that catastrophe occur, the cities and regions that had made prior planning for at least temporary self-sufficiency, would ride the aftermath with the least bloodshed and suffering.

Floating seasteads have the potential to carry their own coral reefs and fish/edible sea creature breeding grounds in the flotation undercarriage--so healthy aquaculture should be easily possible. Energy supplies should be no problem, given the diverse and relatively constant nature of renewables available. Food crops could be grown via aeroponics/hydroponics, so there would be no need to hoard soil (as in "Waterworld"). Freshwater could be supplied via solar distillation, OTEC flash distillation, nano-facilitated electrolysis, etc.

In the case of a killer pandemic or nuclear fallout contamination of large cities and croplands, a floating seastead would provide the type of isolation that might allow the survival of fairly large populations. A successful large-scale seastead would also involve large scale underwater operations--giving scientists a perfect testing platform for various technologies useful in a permanent undersea habitat.

Those readers familiar with Marshall Savage's Millenial Project will remember that the Aquarius seastead was the second out of 8 steps to colonise the galaxy.

I see the seastead as a floating example of an "arcology" in the broader sense. The arcology concept can be useful for a land-based semi-autonomous city-state, a seastead, an undersea city, an orbital colony-city, a sustainable moonbase, etc.

A good question to ask: what is the smallest human population that can be sustainable technologically, genetically, societally, culturally, etc. The answer would be a bit different, depending upon the topology, resources, and room for expansion. With advances in genetics, the danger of inbreeding in a small population would be more controllable--but that level of genetic control is well in the future.

More on these idle speculations later.