`
SeaSteading -- Homesteading the High Seas
This is one of my
miscellaneous projects.
Like most of my projects, its status is
work in progress.
SeaSteading -- Homesteading the High Seas
A low cost approach to colonizing the ocean surface
is examined. Flotation is accomplished using
thousands of recycled 2-liter carbonated beverage
bottles. Food is grown using tried and true
`victory garden' style gardening, rather than
advanced hydroponics. Power generation is performed
via a combination of photovoltaic, wind, and wave
energy extraction rather than sophisticated
OTEC (Ocean Thermal Energy Extraction.) The net
result is a system that can be developed and deployed
for without expensive R&D, thereby reducing risks
and increasing investor confidence.
Why would anyone want to colonize the ocean surface?
There are a number of reasons -- adventure, religious
freedom, tax avoidance, trying out new forms of
government, etc. Of the ones listed, tax avoidance
is my pick as the most powerful motivator for the
development of sea surface colonization technology.
In my meanderings around the Web, I have run across
three organizations that are discussing the possibility
of colonizing the ocean surface -- the
Atlantis Project, the
New Utopia Project, and the
Millennial Project (now the Living Universe
Foundation.) There are probably others, but these
are the ones I have encountered so far. Both the
Atlantis and New Utopia project appear to be in the
`trying out new forms of government' camp. The
Millennial Project is based around the concept of
colonizing the ocean surface as the first step
towards colonizing the galaxy as described in Marshall
Savage's book The Millennial Project: Colonizing
the Galaxy in Eight Easy Steps
[Savage1992].
It is my personal opinion that these efforts
will fail because they are currently structured as
fairly big and expensive projects that will have a
very difficult time attracting the requisite capital.
I claim that it is difficult to raise millions of
dollars in capital, when an investor has the opportunity
to invest their money in the current hot area (as
I write this -- Internet stocks) and double their
money in six months. I would be delighted
to be proven incorrect in my prediction.
This paper proposes a different strategy to achieve
the colonization of the ocean surface. By way of
analogy, the western territories of the United States
were not colonized by a few well financed colonization
efforts, but instead the west was colonized by tens of
thousands of more individualized efforts. One of the
primary ingredients was the Conestoga wagon technology.
The Conestoga wagon was affordable by individuals
and allowed them to successfully take their
possessions to their eventual destination. In the
discussion below, I intend to outline some technology
that is within the financial means of individuals
and would allow individuals to colonize the ocean
surface, rather than large colonization corporations.
I call this technology a seastead, for `SEA homeSTEAD'.
I currently live in the United States and it is
at this time a very litigious society.
As I have read up on ocean technology, I have gained
a very healthy respect for the ocean and how dangerous
it can be. If you decide to do any of the things
mentioned in this paper, be sure to do your own
independent research to decide how dangerous the
activity is. I assure you that I have no intention
of living in the middle of an ocean without first
verifying that my flotation device can withstand
some serious ocean storms. I recommend that you
take similar precautions.
I do not guarantee any of the technology presented
in this paper. If you decide to build any of the
technology presented, you do so at your own risk
and I am in no way liable for what happens to you
or your equipment.
Before you can colonize the ocean surface, you need
to prepare the surface for your arrival. Ultimately
this task involves producing some artificial land.
The basic concept is you need to put your land on
top of something that floats; otherwise, you are
colonizing the ocean floor, which is a completely
different engineering task!
Flotation is based on Archimedes principle that
buoyancy is created by displacing water. A boat
accomplishes this task by having a water tight
shell that displaces the water as shown below:
The amount of buoyancy is equal to the total weight
of the displaced water.
As I researched the topic, I discovered that the
concept of artificial islands has been around for
quite while; indeed an entire chapter is devoted
to the concept in chapter 7 of The Future for
Ocean Technology
[Ford1987].
Basically, the artificial island technology to date
is based on barge technology. You take a large
shell and cover it. The problem with barge
technology is that it is not particularly cheap.
The Atlantis Project is based around Sea Cell (tm)
technology. A rough diagram is shown below:
The Sea Cell (tm) concept is based around an air
tight shell that is inverted to displace water.
Again, the amount of buoyancy is equal to the total
weight of displaced water. One of the big problems
with the Sea Cell (tm) technology is that it is
patented an thus has to be directly obtained from
the patent holders. This particularly annoying
since the patent holders are having a difficult
time raising the capital needed to go into serious
production. Thus, even if you wanted to use Sea
Cell (tm) technology, you might have some serious
difficulty getting delivery of them.
The Millennial project wants to build their
flotation devices out of an interesting material
called seacrete or seament. This fascinating
material is manufactured directly from the
dissolved minerals in sea water by passing an
electrical current through a mesh immersed in
the water. Since the one of the goals of the
Millennial project is to use locally produced
materials whenever possible, the desire to use
seament is quite consistent. However, if your
goal is just to live on the surface of the ocean
with as little investment as possible, seament
may not be the most economical material to use.
Seament requires a lot of electricity to
manufacture. The Millennial project assumes that
OTEC (Ocean Thermal Energy Conversion) will
provide the requisite amount of power; unfortunately
OTEC is still fairly early in its development
cycle, so its economic viability have not yet
been demonstrated. If you are using an alternative
form of energy (e.g. photovoltaic, wind, etc.),
the cost of seament will be quite high. I think
most seasteaders will opt for less expensive
flotation solutions if they are available.
The flotation method I describe below uses
thousands of recycled 2-liter plastic beverage
bottles. A cross section of 2-liter bottle is
shown below:
Plastic beverage bottles have a number of advantages:
-
Availability
-
Large numbers of the bottles are simply
thrown away. They can be yours for free
if you simply agree to haul them away.
Many states/communities have recycling
programs where the bottles are collected
for eventual recycling. It may be possible
to get significant numbers of bottles by
purchasing the bottles from the recycling
center. If the hassle of getting a sufficient
number of recycled bottles is a problem,
you can always purchase new bottles in bulk
quantities from a number of competing bottle
manufacturers. Indeed, you might be able
to dig around in you garbage right now and
find enough bottles to start your own
flotation experiments!
-
Cost
-
Millions of these bottles are manufactured
every day. They can be directly purchased
in bulk from numerous competing manufacturers
or they can be purchased from a recycling
center or they can be obtained for free by
asking for them. So even though you are
going to need thousands of them, they will
still be quite inexpensive
-
Durability/Resiliancy
-
The plastic bottles are quite resistant to
corrosive sea water. In addition, since
thousands of bottles are being used for
buoyancy, numerous individual bottles
can lose their pressurization without
affecting the overall buoyancy.
-
Incremental
-
You can add surface area to your seastead
incrementally.
The bottles are pressurized to about 2 atmospheres
and assembled into 7 bottle hexagonal cells. The
hexagonal cells are assembled into large sheets
and stacked on top of one another to get the desired
amount of buoyancy.
Now I will get into some of the details. The first
issue is bottle pressurization. Why pressurize
the bottles? Well, as unpressurised bottles are
pushed deeper and deeper into water, the greater
water pressure will start to collapse a bottle
that is at one atmosphere of pressurization.
Water pressure is approximately two atmospheres
at a little less than 10 meters (32 feet for those
of you who like English units.) As long as the
bottle is pressurized to two atmospheres, it can
be pushed under water to a depth of almost 10
meters before it starts to crumple.
You can pressurize the bottle any way you want.
I can envision a special attachment that grabs
onto the bottle lip, makes an air tight seal,
pressurizes the bottle, screws on the bottle cap,
and releases the bottle. Unfortunately, such an
attachment sounds pretty expensive to me. I want
a low technology solution. My alternative proposal
(I have not tried this yet) is that you buy a chunk
of dry ice and some nice thick gloves. You break
off small pieces of the dry ice. You drop a small
piece of dry ice into each bottle and screw the
cap on. Eventually the dry ice sublimates and
pressurizes the bottle. If the piece you drop in
is too big, well, the bottle will pop (sort of
like a balloon) and you need to get another bottle.
What ever dry ice is left over can be thrown into
a punch bowl to produce a really neat bubbling
punch! Anyhow, it does not matter how you pressurize
the bottles just so long as they are pressurized.
The next trick is to band the bottles together into
a hexagonal bottle grids. My preference is that the
bottles point down. That way if the cap leaks pressure,
the inverted nature of the bottle will still displace
the required amount of water. The bottle grid
consists of seven bottles arranged in a hexagon
as shown below:
The bottles are attached to one another using
nylon fishing line and a little dab of hot glue
to prevent the knot from coming loose. The fishing
line is wound around each bottle by 420 degrees
to ensure that the bottles are firmly attached
and so that the hexagon cells can be nestled next
to one another without bumping into the fishing
line. In addition, for the stacking step, the
lips around the bottle necks are going to get
in the way, so they need to be clipped off using
some tin snips.
The bottle can be stack on top of one another by
simply ensuring that the necks of top layer fit
into the interstices of the lower layer as is
shown in the top view below:
Note how the bottle necks fit directly into the
bottle interstices on the layer below. While
gravity and the buoyancy of the lower bottles
pushing up should be adequate to keep the bottles
joined together, it seems prudent to wrap a little
fishing line around them all to ensure that the
stay together. A cross-sectional view of some
bottles stacked on top of one another is shown
below:
There is an issue of how to design the sides
of the flotation. If there is a flat side,
the ocean waves will hit the side and splash up.
Flat sides will probably have to be built up
into fairly high walls to prevent the ocean
waves from broaching the walls and spilling
plant killing salt water all over your crops.
An alternative is to put a sloping barrier
around the perimeter so that the ocean waves
will break and dissipate as they climb the
slope. Probably some combination of the two
is what will ultimately be adopted.
As I was researching sea structures I ran across
the book Materials for Marine Systems and
Structures edited by Dennis Hasson and C.
Robert Crow
[Hasson1988].
This book devotes an entire chapter to the topic
of biofouling -- plant life attaching itself to
your flotation device. In other words -- barnacles
on your bottom! Basically, biofouling occurs
in two steps -- microfouling followed by macrofouling.
Microfouling is the attachment single celled
organisms to the surface. Macrofouling is the
attachment of larger organisms such as barnacles
and mussels. There is a chart on page 105 that
suggests that macrofouling is strongly dependent
on proximity to the shore. The further you are
from shore, the less of a problem it is. If
macrofouling persists, according to the book
on page 115, chlorine is an effective biocide:
There is no consensus about the concentration
of chlorine needed to control macrofouling.
Similarly, no agreement has been reached
about the relative advantages of low-level
continuous chlorination compared to
intermittent chlorination and the application
rates depend on a variety of factors, including
the predominant organisms, growth rates,
location, season, and water temperature.
In general, the soft macrofouling organisms
can be controlled by intermittent chlorination
at a level of 1.0mg/L residual chlorine for
one hour out of every eight hours. Hardshelled
foulers including barnacles and mussels, require
continuous discharge of low-level chlorination
-- 0.25-0.5mg/L of free residual chlorine.
If biofouling becomes a major problem for the
seastead, a system for chlorinating the water
around the seastead may need to be developed.
Since chlorine is a nasty chemical to deal with,
I sure hope that macrofouling does not become a
problem for the deep seastead.
There are a number of issues associated with
transporting the hexagon cells to the seastead
assembly site, assembling them into a large
floating area and then floating them out into
the ocean. I am going to leave these issues
unanswered because I think some experimentation
is going to be needed to figure out the best
answers for these issues. Let me just say that
none of the problems look difficult to solve.
Once you have your flotation surface sitting
in the water, it is time to cover it with dirt!
First, we put a layer of 5 mil black plastic
on top of the bottle ends. Second, we apply
a layer of mixed stones and gravel on top of
the first plastic layer. We rake the stones
and gravel into squares with sloping sides
and a depression in the center as shown below:
The depression in the center are where we are
going to collect fresh water that manages to
seep through the upper layers of soil. Third,
we apply another layer of 5 mil black plastic
on top of the sloping squares. This layer of
plastic prevents fresh water from seeping all
the way through and dripping into the ocean
and is shown below:
Fourth we drop some drop some water level
sensors with pumps into the depressions.
These devices are discussed in the fresh
water management section below. Finally,
we put some more gravel on top of the plastic
followed by layers sand and soil until we have
about half a meter (say 18 inches) of soil.
This should provide an adequate layer of soil
for most crops and vegetation.
If you want to plant trees, a significantly
greater amount of soil depth is needed and
correspondingly greater amount of flotation
under the heavier soil load is required.
Now that we have the prepared the surface of our
flotation with a layer of soil, we can start to
build the remainder of our seastead on top of it.
There are numerous books published on the topic
of being self sufficient and living off the land.
The one I used was Building for Self
Sufficiency by Robin Clarke
[Clarke1976].
There is a decision we have to make about just
how self sufficent we want to be. The more
self sufficient we are, the less material we
have to import into our seastead. The initial
seastead will probably be rather small, so they
will not be as self sufficient as the ones built
later on.
There are two major differences that must be dealt
with as self sufficiency books are applied to seastead
technology. First, even though the seastead is
surrounded by water, fresh water is going to have
to be tightly managed. We do not have the option
of tapping into a stream or drilling a well to get
unlimited supplies of fresh water. Fresh water
management is covered in greater detail later in
the water section below. Second, surface area is
going to be at a premium. Every square meter of
land is going to require at least a hundred recycled
beverage bottles to support it. Large meandering
structures that occupy lots of space are not going
to be viable in early seasteads.
I should comment that most of these self-sufficiency
books start out with a preface that I will paraphrase
as `humanity is running out of energy and resources;
thus, we must change our evil high technology ways
and go back to basic living off the land.' These
statements should not be taken at face value, because
many of them are not supported by scientific evidence.
For example the inflation adjusted cost of energy and
resources has continually declined when measured over
periods of greater than ten years. A more balanced
view of energy and resources can be found in
The True State of the Planet a compendium
of papers written by ten environmental scientists
who publish in peer reviewed journals. The True
State of the Planet is edited by Ronald Bailey
[Bailey1995]. A number of the energy books
I reference below suffer from the same basic
flaw, however, once you get past the preface and
first chapter of these various books, they tend
to be pretty reasonable.
The first issue that I delve into is food production.
When it comes to food production it is necessary
to decide how self-sufficient the food production
should be. There is a spectrum of choices ranging
from importing everything to producing everything
locally. Realistically, the initial seasteads are
unlikely to be a 100% self sufficient due to lack
of available space and experience. For example,
growing wheat for bread will take a fairly large
amount of space; whereas importing a few bags of
wheat is quite inexpensive and easily stored.
A reasonable goal for an early seastead is to be
self-sufficient in fruits and vegetables. The
remaining food staples can be imported.
When it comes to growing food, there is either
standard soil based gardening or soil less
hydroponic technology. To keep things relatively
simple, I suggest starting with regular soil based
gardening and branch out to hydroponic technology
at a later date.
There is a long history of people supplementing
their diet with home grown vegetables. During
World War II, these gardens were called `Victory
Gardens' and the name has stuck ever since. When
I was digging around looking for books on victory
gardens I ran across the book Square Foot
Gardening by Mel Bartholomew
[Bartholomew1981]. What I like about this book
is that it tries to minimize the amount of time
spent in the garden. Most other books seem to
focus on gardening as a hobby and tend to soak
up as much time as they can get.
The square foot gardening method espoused by
Bartholomew starts by asking how much food do
you want to grow. Next, the system figures out
how much area you are going to need. The book
has a heavy emphasis on vertical gardening by
training plants (like peas and beans) to grow
up vertical strings. Vertical gardening makes
a great deal of sense on the seastead where
land is at a premium. The garden is organized
as a grid rather than long rows. Everything is
measured in 1 foot squares. Then you plant the
squares at the right times of the season for the
plants to reach maturity. The food is harvested,
the plain remains are composted and you do it all
over again. The goal of square foot gardening
is to spend just a few minutes a day on garden
maintenance.
The only real disadvantage of soil based gardening
is that it requires soil which must be imported to
your homestead. Hydroponic food production allows
you to grow food without importing soil. My reference
on this topic is Hydroponic Food Production
by Howard Resh
[Resh1978]. A further advantage hydroponic
gardening is that it can generate substantially
more food in a given area than soil gardening.
Given these advantages, it makes some sense to
to start growing some plants hydroponically to
gain experience with hydroponic technology.
Eventually, over time hydroponic technology
will displace some of the soil technology on
the seastead. The amount displaced will ultimately
depend upon how effective hydroponics are.
In addition to the vegetables, it makes sense to
to have a number of fruit and nut trees planted on
seastead to provide a regular supply of fruits
and nuts. Since trees require more than half a
meter of soil, it may be necessary to grow the
trees in raised tubs. These raised tubs will
be heavy, so it may be necessary to add additional
flotation bottles underneath the tree tubs.
One real advantage that the seastead has when it
comes to growing crops is that it is possible to
reduce or eliminate weeds and insect pests. This
is extremely difficult to do on land, since the
weeds and pests are just blown across the property
boundary. With a seastead, care can be taken to
try and minimize the number of insects and weeds
that take hold on the seastead. By immediately
removing any unwanted pests and weeds whenever
they are encountered, it is possible to get to
a state where they have all been eradicated.
Once a crop has been harvested, the plant remains
can be through into a compost heap. Over time a
compost heap will generate new soil that can be
added to the seastead soil. Composting is covered
in both Building for Self-Sufficiency
and Square Foot Gardening.
Now it is time to switch focus over to fresh water
management. Despite being in the middle of an ocean,
obtaining and retaining an adequate supply of fresh
water is going to require some careful thought and
implementation.
Below some various grades of water are defined:
-
Distilled Water
-
Distilled water is water that has desalinated
by evaporation and recondensation. It is
tends to be quite flat to drink. Distilled
water can be aerated to improve its flavor.
-
Potable Water
-
Potable water is water that is clean enough
to be directly ingested and has enough air
and minerals mixed in that it `tastes good'.
-
Rain Water
-
Rain water is water that has been collected
from rain fall. It may have a little dust
mixed in with it that should be filtered out
prior to drinking.
-
Grey Water
-
Grey water is water that has been used once
for either washing, bathing, or showering.
It tends to have a small amount soap mixed
in with it. Grey water can readily be used
to water vegetation.
-
Black Water
-
Black water is water that has bodily waste
mixed in it, either urine or excrement.
With some work black water can be neutralized
to the extent that it can be mixed in with
other grey water for vegetation watering.
The seastead will have a bunch of plumbing to move
the various kinds of water around.
There will be a continual loss of fresh water due to
evaporation and slow leaking. This means that the
fresh water needs to be replenished. There are four
possibilities for water replenishment -- rain water
collection, distilling sea water into fresh water,
reverse osmosis of sea water into fresh water, and
importing fresh water. Of the four, importing fresh
water seems the least practical and rain water
collection seems the most practical.
Rain water collection is the simplest means for
replenishing fresh water. By putting gutters on
roofs and solar collectors we can directly route
rain run-off into some cisterns. It is inevitable
that dust will get mixed in with the runoff. A
simple filter can be used to filter the dust out
in order to make the rain water into potable water.
In addition to gutters, the seastead has been
carefully designed to collect all water that seeps
through the soil. With some additional filtering,
it should be possible to filter this water to remove
the soil particles and convert it into potable water.
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.
The soil has been carefully designed to have
collection depressions for collecting any fresh
water that seeps through. A device that is a
combined water level sensor and a small electric
pump can be placed at each depression. When the
depression starts to fill up with water, the water
level sensor triggers and the pump starts to pump
the water away. These combined pump/water level
sensors will have to be carefully designed to
last a long time; otherwise, they will have to
constantly dug up and replaced. After a rain
storm the resultant rain water run off can be
pumped out from under the soil and into a rain
water cistern. It may make sense to direct the
soil rain run off to a grey water cistern and
the gutter run off to a potable water cistern.
To further conserve water, all crops and landscape
vegetation should be irrigated with drip irrigation.
To further conserve water, the irrigation system
should be run at night to reduce evaporation due
to sunlight.
The dwelling should have both black water and
grey water drainage systems. The black water
drain is connected to the toilets and the grey
water is connected to the sinks, showers and
baths. The grey water can be lightly treated
and then directed to a grey water storage tank
for subsequent crop and landscape watering.
The black water drainage needs to be treated
before it can be reused. One possibility is
to use a septic tank. Another possibility is
to use algae treatment ponds. Somebody (not
me) is going to have to figure it all out.
One concern that must be dealt with is salt
water contamination of the soil. As waves
crash in the ocean around the seastead, small
droplets of ocean water are formed that are
blown around by the wind. These small droplets
can land on the soil and slowly increase the
soil salinity. Once the soil becomes too salty,
crops will no longer grow. One solution is to
do all crop growing in covered greenhouses on
the seastead. I could not find any reference
that would give me an idea of how serious a
problem salt contamination will be.
Our seastead is going to need some power to run various
tools and appliances. The Aquarius project proposed by
the Millennial Foundation proposes to use OTEC (Ocean
Thermal Energy Conversion) technology for energy production.
There are numerous advantages to OTEC technology -- it
works night and day, it brings nutrient rich water to
the surface, and it produces fresh water as a side effect
of its operation. Unfortunately, it has some problems
too -- it is big, capital intensive, and is currently
only available in prototype form. There are other
workable alternatives that are both less capital
intensive and more technologically mature -- solar power,
wind power, and wave power. (Nuclear power is yet another
alternative, but it is extremely capital intensive and
politically difficult; in terms of seasteading, nuclear
power makes OTEC technology look easy.)
Basically all of the alternative power sources have
one problem in common -- the power is intermittent.
Solar power does not work a night, wind power does
not work when the winds are calm, and wave power
does not work when the seas are calm. The only
effective solution to this problem is collect and
store excess energy for times when power generation
is not available. For now, the most mature technology
for storing energy appears to be electro chemical
batteries. Since we are going to need a battery system
anyway, it means we can use a combination of solar,
wind, and wave power as suits our needs.
There are a variety of different forms of solar
power -- photovoltaic, solar heating, solar dynamic,
etc. For this paper, I am going to focus on
photovoltaic power.
Photovoltaic (i.e. solar cells) technology was
originally developed to supply power to satellites
in outer space, a remote and hostile environment.
Currently, photovoltaic power can make economic
sense for remote areas that do not have a connection
to the electric power grid (like seasteading.) There
is now a large body of practical experience with
photovoltaic power that can be applied to our seastead
application. The reference I used was The New Solar
Electric Home by Joel Davidson
[Davidson1987]; I am sure there are plenty of other
appropriate alternative books on the subject. Like
the self-sufficiency books above, each of the solar
power books tends to have the same preface about how
we are running out of energy. As usual, please
discount the preface and first chapter and move onto
the rest of the book, which is typically quite
pragmatic.
Photovoltaics have a number of disadvantages:
-
Cost
-
Photovoltaic panels are expensive. They
keep coming down in price, but they are
still not cheap.
-
Efficiency
-
Even the most efficient photovoltaic cells
have only recently started to achieve
conversion efficiencies over 30% and these
are horrendously expensive. The commercially
available solar panels have conversion
efficiencies in the 8-15% range.
This relatively low energy conversion
efficiency means you need more solar panels
to achieve the desired level of power generation.
-
Battery Storage Required
-
Since the sun does not shine at night, there
is no power coming in from the solar panels
at night. To work around this problem, the
it is necessary to collect additional energy
during the day and store it for night time
use. The most common energy storage method
is to use a bank of bateries. The batteries
are expensive and the extra energy collection
increases costs as well.
Despite these disadvantages, they have a proven
track record for remote power generation.
Like solar power, wind power is a fairly mature
technology that has been around for quite a while.
When people think of wind power, the vision of the
wind powered pump on a tower on a farm comes to mind.
There are a number of more modern wind turbine designs
as well. The reference I used for wind power was
Harnessing the Wind for Home Energy by
Dermot McGuigan
[McGuigan1978]; as for photovoltaics, there are
numerous appropriate alternative books on the subject.
Again, most of these books start out with a statement
of the form `we are running out of energy' that should
be discounted.
Wind power has one major advantage over photovoltaic
generation -- 24-hour a day power extraction is
possible. While there are times when the wind dies
down, it possible to place a seastead in a location
where that occurs infrequently. With continuous
power extraction, a large power storage system
based on batteries can possibly be avoided.
Wind mills can be broken into two broad catagories
that are defined as follows from the book:
-
Horizontal Axis
-
Where the propeller (or rotor) on a horizontal
shaft or axis moves in a plane perpendicular
to the direction of the wind. This includes
multi-blade, four-arm and high-speed propeller
types
-
Vertical Axis
-
Where the rotor on a vertical shaft or
axis has its effective wind-catching surface
moving in the direction of the wind. This
includes the more recentlhy developed
Darrieous and Savonius rotors
The standard rotor on a tower with a vane coming
out the back is a horizontal axis wind mill.
Vertical axis wind mills are not as common,
but are commonly referred to as `egg beaters'
or `oil drums'.
It can be shown that windmill are operating at peak
energy efficiency when they have slowed the wind
down by about two thirds. Thus, wind mills have
to let some of the wind get through.
The seastead is free to use any form of wind mill;
they all work with varying degrees of efficiency.
My current favorite is the Savonius rotor, sometimes
referred to as an oil drum rotor. A cross section
of a Savonius rotor is shown below:
Of all the wind mill generators available, the
Savonius rotor is the least efficient. However,
it also looks like its very easy to fabricate,
since many Savonius rotors are manufactured out
of old oil drums. Ultimately, what matters is
not wind mill efficiency, but cost times efficiency.
If cost is sufficiently low, additional power is
obtained by simply erecting additional wind mills.
When horizontal space for the wind mills runs out,
it turns out that Savonius rotors can be stacked
on top of one another.
There is one additional disadvantage associated
with wind power. As the wind blows through the
wind mill, most of the extracted energy is being
converted to electricity. However, some of the
wind power is pushing against the wind mill and
causing the seastead to be blown with the wind.
Some experiments will need to be performed with
wind power to figure out how severe the wind
pushing problem is.
As I was digging around in the alternative energy
section of the library that I use, I came across
a book with the interesting title of Power
From the Waves by David Ross
[Ross1995]. That book exposed me to the
interesting concept of extracting energy from wave
motion. Obviously, the middle of an ocean is a mighty
good place to find a bunch of waves. Unfortunately,
the book by Ross largely chronicles the efforts to date
to extract wave energy in Great Britain to be feed into
the power grid. Most of the designs are pretty capital
intensive and, hence, are not very appropriate for
an inexpensive seastead. However, further research
uncovered a book called Ocean Wave Energy
Conversion by Michael McCormick
[McCormick1981]. Again, most of the technology
described in the book is quite capital intensive
and, hence, not appropriate for the inexpensive
seastead. However, on pages 110-117, an ingenious
devise called the Russell Rectifier is described
and a low cost implementation may be available for
the seastead.
If you have had any experience with electronic
circuitry, the Russell rectifier is the hydrolic
equivalent to a two diode electronic rectification
circuit. A diagram of a Russell rectifier can
be found below:
The system consists of two water reservoirs which
I have respectively called the "high water reservoir"
and the "low water reservoir". The high water
reservoir is connected to the ocean via a one
way valve that only lets water flow from the
ocean into the high water reservoir; this will
only occur when the wave crest is higher that the
water level in the high water reservoir. Similarly,
the low water reservoir is connected to the ocean
via a one way valve that only lets water flow
from the low water reservoir to the ocean; again,
this will only occur when the wave trough is
below the level in the low water reservoir. A
water turbine is connected between the two reservoirs
that is driven by the difference in water levels
of the two reservoirs. In general, the difference
in water levels in the two reservoirs is directly
proportional to the average ocean wave height.
If the the seastead is currently experiencing
2 meter waves (i.e 6 feet for the metric impaired),
the turbine will have a pressure head of 2 meters
to work with.
While there are other wave extraction technologies
that are probably more efficient at extracting
energy from the waves, the Russell rectifier looks
like it will be quite inexpensive to construct
since it consists of a couple of simple reservoirs,
some piping, some one way valves and a low pressure
water turbine. The diagram below shows a few
enhancements to Russell rectifier to make it
easier to build and maintain.
The primary enhancement is that the valves and
turbines have been moved to the top surface where
they are more easily maintained. This way it
is not necessary to dive over the edge just to
inspect the valves and turbines. Instead, they
are at `ground level' where they can easily be
maintained. The one-way valves can have clear
plastic view ports to allow easy inspection.
In order to get the whole system started, you
simply suck the air out to get the water
siphoning around the system. This requires
a small air valve at the highest point of each
one way valve and the turbine. A small electric
or manual vacuum pump can be used to remove
the air to get the water siphoning through the
system.
In addition, all of the pipes simply hang over
the edge of the seastead into the ocean and
over the edge of the reservoirs. A few moments
of thought should convince you that all that matters
is the difference in heights between the ocean and
the reservoirs and not the actual placement of
inlet and outlet pipes. As long as the pipes
do not try to span more the about 10 meters
vertically, the water can be moved around
by the siphon effect.
So how cheaply can such a system be built? Well
all of the piping can be done with inexpensive
four inch PVC sewer pipe. The reservoirs can be
made out of heat sealed plastic liners. By the
way, it is not the end of the world if the reservoirs
are a little leaky. The one way valves can be
adapted from flapper valves used in toilet flush
mechanisms. Some plastic insect screen can placed
over the ocean inlet and outlet pipes to prevent
fish and other debris from getting into the system
and mucking things up. Everything can be glued
together using PVC glue. The most expensive part
of the system is the low pressure water turbine.
Again, we do not need to have the world's most
efficient water turbine; we can make trade offs
between cost and efficiency. What is fun about
this system is that someone could probably build
a prototype using some garbage cans for reservoirs,
some PVC sprinkler pipe for plumbing, and plunge
a basketball into and out of a third garbage can
to simulate waves. I suspect that is would be
possible to build such a prototype and keep the
entire cost of the system under $100. Any takers?
Are there any enhancements that can be applied
to a Russell rectifier to improve its efficiency?
Well, it probably the case that some sort of
wave guide could be attached to the side of
the sea stead to funnel the waves together.
This would result in higher wave crests and
ultimately a higher pressure head to drive the
water turbine. For starters, these enhancements
can be simply skipped over
So the question arises, `Which power generation
system should a seastead use?' The answer is
probably a combination of the above. For right
now, my bet is that the photovoltaic with storage
battery technology is the most mature. Next,
it would be interesting to put up some wind
power generators to see if they can provide
supplemental power generator for night time use.
The Russell rectifier wave power generator is
still basically speculative and should be prototyped
to see if any useful amount of energy can be
extracted from waves.
But what happens if you have a bunch of cloudy
low wind days (i. e. reduced solar, wind and wave
power?) Well, you either put up with the power
failure (i.e. break out some lanterns and
candles for lights) or you fire up your fossil
fuel backup generator; these are the exact same
options that most people face when their power
grid power fails.
An integrated system of photovoltaic, wind, and
wave power with battery storage and ultimately
a fossil fuel backup generator should provide
a very high level of power availability to the
seastead. Such an integrated system should still
cost substantially less than an OTEC system
for the small and medium sized seastead.
Is the seastead a boat or an island?
If a seastead is an island, then is should be
attached to the ocean floor to prevent it from
moving around. Since the ocean floor is typically
five miles from the ocean surface, attaching the
seastead to the ocean floor is actually quite
challenging. An other alternative is to have
steerable propellers in a feedback look with
GPS (Global Positioning System) that can push
the the seastead to its desired location whenever
it starts to drift off location.
My preference is to treat the seastead as a boat.
For one thing, this means that all of the
international law that applies to boats can
be applied to a seastead. In addition, this
means that when some bad weather is headed
for the seastead, the seastead can try to
avoid the bad weather. In addition, when
supplies are low, the seastead can find a
port and resupply itself. In all cases, an
ocean going seastead will find it useful to
have some sort of sea worthy boat to go
between the seastead and shore.
The seastead is not designed to travel at
high speeds. Thus, a number of trolling
motors thrown over the side and hooked up
to the electrical system will probably be
adequate for seastead movement. Some sort
of control system will be useful so that
all of the propellers can be automatically
lined up to point in the same direction
without having to run around the seastead
an manually point each one.
Once the first few seasteads have been deployed,
they can aggregate into small sea villages by
simply rendezvousing at a agreed upon location
and lashing all the seastead into one bigger
sea village. A little planning in advance
can make this very easy. For example, let us
assume seasteads are constructed to be rectangular
in shape. If we place a short `road' across
the narrow end of each seastead, the seasteads
can be lined up so that the `road' can be used
to access each seastead. This is shown in the
figure below:
Over time the sea communities will evolve from
simply linear collections of seasteads, to
grids and ultimately to sea cities. Whenever
someone becomes annoyed with the current state
of a seastead community, it is possible to just
disconnect and take your seastead some place
else.
There is not much that I would like to say about
shelter. The shelter can be as simple as a tent
or as complicated as a multilevel house. For
initial seastead prototypes, my suggestion is to
simply get some sort of inexpensive RV
(recreational vehical) trailer and simply park
it on one end of the seastead. An RV trailer
provides sleeping accomedations, a small kitchen,
a small bathroom, a place hang out, etc.
Since most RV trailers already have separate
grey and black water tanks, it sould be very
easy to integrate the trailer into the fresh
water management system.
If it is desirable to watch television, a satellite
dish can be installed to pick up satellite signals.
This next section contains my opinions about the
current state of affairs with regards to seasteading.
Obviously, some people may not agree my opinions;
they are welcome to write and publish their own paper
outlining why they I am wrong.
Given enough money and will it is possible to build
just about any kind of structure in the middle of
the ocean that you can think about. Unfortunately,
the tough part seems to be coming up with enough
capital to make it happen. Let us examine the state
of the Atlantis, Millennium, and New Utopia projects.
There has been very little visible progress with the
Atlantis project for quite a while. It is quite likely
that the Atlantis project is totally defunct.
The Aquarius portion of the New Millennium project seems
to have gone through a number of phases:
-
Phase 1 (Enthusiasm):
-
Initial enthusiasm and excitement
-
Phase 2 (Replan):
-
Several replans to reduce project costs
-
Phase 3 (Bummer):
-
The growing realization that even the rescaled
plans are still too expensive
-
Phase 4 (Slow Death):
-
Growing disenchantment with the whole project
and a slow exodus of people working on the
project. (This last part is still a bit
speculative.)
The New Utopia project is probably roughly in phase 1.
I predict that the New Utopia project will soon enter
the redesign phase when when the desired levels of
investment fail to materialize. (Remember, this
is my prediction; other people are free to disagree!)
I suspect that New Utopia will follow roughly the
same path that the New Millennium project has.
Basically, the amount of capital required to build
either Avalon or New Utopia is simply too high to
be realistically raised. When an investor can put
their money into an internet stock and double their
money in 6 months, it is awfully hard to make a
business case for a large artificial island that
has no real intrinsic economic value.
My proposed solution is to start very small and
cheap and slowly build up to the desired goal of
a fairly large artificial island in the middle of
the ocean. By keeping the initial costs low,
it is possible to build the initial versions and
show potential investors what they are getting
into at each step of the way.
I figure that an initial 1 acre seastead could be
built by a relatively small dedicated team of
volunteers for between $10,000 and $100,000
depending upon how hard people scrounge for things.
While the this initial seastead would not be
suitable for seasteading the high seas it could
almost certainly survive indefinitely in a large
harbor (e.g. San Francisco Bay or the Puget
Sound) or a lake (e.g. Lake Michigan.)
If I had to select an initial site for a prototype
seastead, I would probably select either the San
Francisco Bay Area or the Puget Sound. Why? The
computer industry has generated a simply astonishing
number of individual multi-millionaires in the San
Francisco Bay and Seattle areas. The future phases
of seastead development could definitely benefit
from the positive attention of a few millionaires.
By locating the initial seastead prototype in one
of these two areas, it is far more likely that one
of these multi-millionaires will become interested
in the seasteading project.
For the sake of argument, let us hypothesize that a
team of 20 people from around the United States
decide to get interested in a seastead prototype.
These 20 people commit $500 towards the project.
Most people spend well over $500 a year on their
personal hobbies (e.g. RC planes, model trains, etc.)
This gives the project a $10,000 budget to play
with. Since $10,000 is not much money, it will
have to be spent very carefully.
The next step is to identify a staging area. A
staging area has some property at which materials
can temporarily be stored. It has a pier that goes
out into a body of water of sufficient depth that
the prototype seastead will not run aground.
Furthermore, the staging area needs to be able
to park the seastead for years at time as it
undergoes development. With a budget of $10,000,
an outright purchase of the staging area seems
unlikely. Some sort of deal will be required.
In parallel with the staging area, a number of
small experiments can be performed. A small
number of hexagon cells can be manufactured and
tested for buoyancy, interconnect properties,
and the like. Somebody who has a back yard
can lay a bunch of beverage bottles on end,
and see how well the plastic-gravel-plastic
technology works for building up a soil base.
Someone can figure out the water level sensor
and pump system for moving water water at the
bottom of the soil depressions around. One
person each can experiment with photovoltaic
energy generation, wind energy generation, and
wave energy generation. A lot of additional
research can take place -- how does a septic
tank work?, how much area is required to be
self sufficient in fruits and vegetables?,
etc. One person can be a librarian who collects
books and articles that are relevant to the
project.
After all of the initial experiments and research
have been completed and the staging area has been
selected it is possible for the team to design
the first prototype seastead. A complete budget
is assembled to figure out what everything is
going to cost, staging area costs, materials,
any special labor costs, and special tools,
etc. Now them moment of truth has arrived. Is
there enough money in the budget? If it is close,
perhaps the team members can kick in some additional
funds. If it is way off, it may be necessary to
scale back the seastead plans some and try again.
Eventually a coherent prototype seastead design
and a realistic budget comes out of this process.
Now comes a lot of rewarding hard work. Probably,
the team members will assemble some number of
hexagon cells at their respective homes and
apartments. Plans are made to transfer all of
the cells to the staging area. The people who
live closest to the staging area will be able
to make multiple hexagon cell trips. The rolls
of plastic sheet, piles of stones, gravel and
sand arrive at the staging area. Finally, the
materials have all arrived and it is time for
everybody to synchronize their vacations to
arrive at the staging area to build the seastead.
When everybody arrives, the hexagon cells are
put into the water and stacked on top one another.
A prebuilt sloping ramp is used to get from the
end of the pier to the top of the flotation.
The plastic sheeting is spread out. A lot of
wheel barrow trips are made to get the stones
on top of the flotation. The stones are graded,
additional plastic is spread down. The level
sensors and pumps are put into the water
collection depressions. More gravel, sand and
soil is spread down. The flotation is starting
to sink into the water from the weight of the
stones, gravel and soil. As with any prototype
effort, problems crop up and are solved on the
spot. Eventually, after a week or two, the
prototype seastead is sitting there in the water,
and it is ready for the first person to sleep on
it over night.
Now comes a period of a year or two where people
come out to the prototype seastead and to tend
the garden, add features, fix problems that develop,
etc. In addition, now that there is a seastead to
actually look at, some public relations can be
done. Publish a few papers about the entire project.
Invite the local newspapers to come on out for a
tour. Indeed, invite the general public to come
on out for one weekend a month. Charge an admission
fee to recoup some of the expenses. Use the general
public tours and public relations efforts to recruit
more people to the cause. If you are lucky some
multi-millionaire will get really interested in the
project; if not, well at least you tried.
After the first prototype has been built and tested
for a couple of years, it is time to take all of
that experience and design the second prototype.
The second prototype has a goal of being a sea
worthy seastead that can be taken out into the
middle of the ocean. Are recycled beverage bottles
really going to work for a sea going seastead? How
serious is salt contamination of the soil? The
second seastead will probably cost about ten times
what the first one cost. But the first one has
generated enough interest in the public that it
will probably be possible to raise ten times the
money.
This process of building prototype seasteads continues
until somebody comes along and says `I think it makes
good business sense to form a company that builds
seasteads and sell them.' Success! Now the seastead
technology is going mainstream! I will leave the story
at this juncture.
Let us compare this strategy with the strategies being
employed by the Atlantis, Millennium, and New Utopia
projects. All three of these projects require significant
up front investment from investors. Which strategy do
you think has a greater chance of happening? A
bootstrapping process from small prototype seasteads
or going straight to the ultimate city on an artificial
island that skips all the intermediate steps? My
opinion is that the bootstrapping process is far more
likely to succeed.
In summary, enough technology already exists to
create a viable seastead. Flotation can be
accomplished using thousands of recycled 2-liter
beverage bottles. Standard gardening techniques
can be used to grow fruits and vegetables. A
combination of solar, wind, and wave generators
can be used to provide locally generated power.
Off the shelf trolling motors can be used to
provide seastead propulsion. A commercially
manufactured RV trailer provides a perfectly
workable shelter containing a bathrwoom, kitchen
and sleeping accomidations. No expensive R&D
on seacrete or OTEC is required to make the
seastead a reality.
By starting with small prototype seasteads,
and slowly working towards larger and larger
ones, it is possible to avoid requiring huge
cash infusions to complete the project.
Instead, each stage of seastead development
uses the prior stage of development to reduce
risk and increase investor confidence.
I would like to acknowledge that I found both
the Atlantis project and Millennial project to
be the primary inspiration for even thinking
about the concept of seasteading. I did not
discover the New Utopia project until most of
the ideas in this paper had already solidified.
-
[Bailey1995]
-
Ronald Bailey: 1995.
The True State of the Planet
(New York: Simon & Shuster -- Free Press)
ISBN: 0-02-874010-6
-
[Barhtolomew1981]
-
Mel Bartholomew: 1981.
Square Foot Gardening
(Emmaus PA: Rodale Press)
ISBN: 0-87857-341-0
-
[Clarke1976]
-
Robin Clarke: 1976.
Building for Self Sufficiency
(New York: Universe Books)
ISBN: 0-87663-945-7
-
[Davidson1987]
-
Davidson, Joel: 1987.
The New Solar Electric Home
(Ann Arbor: AATEC Publications)
ISBN: 0-937948-09-8.
-
[Ford1987]
-
G. Ford, C. Niblett, and L. Walker: 1987.
The Future for Ocean Technology
(London: Frances Pinter)
ISBN: 0-86187-522-2
-
[Hasson1988]
-
Dennis F. Hasson, and C. Robert Crowe (ed.): 1988.
Materials for Marine Systems and Structures
(London: Academic Press)
ISBN: 0-12-341828-3)
-
[McCormick1981]
-
Michael P. McCormick: 1981.
Ocean Wave Energy Conversion
(New York: John Wiley & Sons)
ISBN: 0-471-08543-X
-
[McGuigan1981]
-
Dermot. McGuigan: 1978.
Harnessing the Wind for Home Energy
(Charlotte VE: Garden Way Publishing)
ISBN: 0-88266-117
-
[Resh1978]
-
Howard M. Resh: 1978.
Hydroponic Food Production
(Santa Barbara: Woodbridge Press)
ISBN: 0-912800-54-2
LCCCN: 78-23468
-
[Ross1995]
-
David Ross: 1995.
Power From the Waves
(New York: Oxford University Press)
ISBN: 0-19-856511-9
-
[Savage1992]
-
Marshall T. Savage: 1992.
The Millennial Project: Colonizing the
Galaxy in Eight Easy Steps
(Denver: Empyrean Pub.)
ISBN: 0-316-77163-5.
LCCCN:94-15965
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Wayne Gramlich.
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