The Potential of Tidal Energy for Small Island Developing States and other states, as well

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The Potential of Tidal Energy for Small Island
Developing States (and other states, as well)
by Scott Anderson, PhD Coordinator, The
Tide-Energy Project Near the Mouth of
the Amazon
Presentation made at CSD-15 May 2007 updated
September 2009
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The Potential of Tidal Energy for SIDS

• There are four basic questions you may have about
  Tidal Energy
• 1. Does my country have Tide-Energy potential?
• 2. Can Tidal Energy be captured in a simple,
  inexpensive way?
• 3. How can we evaluate our Tide-Energy
  potential?
• 4. Can we get technical assistance to make an
  initial evaluation?

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1. Does my country have Tide-Energy
potential?

• Examine the map in the next slide and determine
  if your country is in or along a red area where
  there is more intense Tidal Energy.
• If that is the case, you may have Tide-Energy
  potential that can be evaluated easily and
  inexpensively.

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The worldwide distribution of Tidal Energy
On the map below, determine if your country is in
or along a red area.
Asia
N. America
Africa
Pacific Ocean
S. America
Indian Ocean
Atlantic Ocean
Red areas in the ocean have more intense Tidal
Energy.
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The worldwide distributionof Tidal Energy
These countries can receive significant benefits
from Tidal Energy

• Indian Ocean Comoros, Madagascar, Maldives,
  Seychelles.
• Asia China, India, Indonesia, Korea,
  Philippines, Vietnam.
• Pacific Ocean Fiji, Kiribati, Micronesia, Palau,
  Papua New Guinea, Samoa, Solomon
  Islands, Timor, Tuvalu, Vanuatu.
• Central and South America Argentina, Brazil,
  Ecuador, Guyana, Panama, Surinam.
• Atlantic Ocean Cape Verde.
• All coastal nations with tidal passes between
  coral reefs or offshore islands.

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2. Can Tidal Energy be captured in a simple,
inexpensive way?
Yes, with a helical turbine.

• Schematic view of a standard, 3-blade Gorlov
  helical turbine mounted in a frame
  with a generator

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Features of the helical turbine

• Operation of the helical turbine
• designed for hydroelectric applications in
  free-flowing water
• does not require expensive dams that can harm the
  environment
• operates in tidal, ocean, and river currents
• rotates in the same direction regardless of the
  direction of the flow, so it is ideal
  for tidal currents flowing in and flowing out

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Features of the helical turbine

• Requirements
• In order to generate electricity effectively with
  the helical turbine, the flow of water at a
  site must be at least
• 1.5 meters per
  second
• In addition, the faster the current,
  the more energy that can be captured.
• This is very
  important !

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Features of the helical turbine

• But, does it work well?
• Yes, it is very efficient 35
• And how much does it cost?
• Small helical turbine blades are not currently
  available on the market for purchase.
• Their availability and price are now under
  discussion with the manufacturer GCK/Lucid.

Disclaimer the presenter has no financial
interest whatsoever in that
company or in the sale of these blades.
If I can find a better technology, I
will use it.
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Features of the helical turbine
Easy to build

• The skilled carpenter and mechanic (above) and a
  local welder built all of the equipment necessary
  to mount the blades and generate electricity.

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Features of the helical turbine
A complete helical turbine generating system
(c) automotive alternator to charge
batteries
(b) drive shaft, pulley, and belt
(a) special 6-blade helical turbine
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Features of the helical turbine
Locally built

• About 80-90 of a Tide-Energy station can be
  built using locally available labor,
  materials, and equipment.
• The technically refined helical turbine blades
  are the only outside components.
• The total cost of a generating system would
  depend on both of these items.

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Features of the helical turbine
Benefits

• Energy production 120 Ampere-hours/day
• That is sufficient to meet basic needs of 10
  households at World Bank standards for
  solar, rural electrification projects.

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3. How can we evaluate our Tide-Energy
potential?

• Each Tidal Energy site has different
  characteristics that can affect its usefulness.
  These include the shape of the coastline or slope
  of the sea floor near the site, as well as its
  distance from local populations who have a demand
  for energy.
• Therefore, each Tidal Energy site should be
  evaluated individually.
• Two important characteristics of a Tidal Energy
  site to evaluate are
• 1) the location of the site in relation to
  the user of the energy
• 2) the measured speed, duration, and
  frequency of the tidal current at the
  site

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3. How can we evaluate our
Tide-Energy potential?
Step 1 Select the better
Tide-Energy sites What is a better Tide-Energy
site? The better Tide-Energy sites will have fast
tidal currents and be

• close to users of the energy
• or convenient for users to reach, especially by
  boat,

because of the need to transport batteries to the
site to be recharged.

• Important a Tide-Energy generation system
  stores energy in batteries. Because the
  capacity of batteries is limited, the batteries
  will probably have to be recharged every 3 to 7
  days, if used by households for lighting and
  other domestic purposes. Also, the batteries
  themselves are heavy, so it may take an effort to
  transport them to a site to be recharged.

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3. How can we evaluate our
Tide-Energy potential?

• How can we select the better Tide-Energy sites?
• use local knowledge
• use maps and nautical charts

Persons with reliable knowledge of
(1) places with fast tidal currents and
(2) where people live in the surrounding
areamay be able to select the better Tidal
Energy sites merely with the aid of maps and
charts. If so, Step 1 can be completed quickly
and inexpensively without the need for fieldwork
to determine these features.
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3. How can we evaluate our
Tide-Energy potential?

• Step 2 Measure the tidal current at
  the better sites
• There are three key measures to evaluate the
  tidal current at a site
• 1) How fast? As stated above, the flow
  of water at a site should be at least
  1.5 meters per second, or 3 knots.
• 2) How long? That flow should occur for
  at least 6 hours per day.
• 3) How often? Flow at that speed and for
  that time should occur on at least
  14 days per monthly tide cycle.

What equipment do we need to measure the speed of
the tidal current? You can make useful
measurements using very simple equipment.
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3. How can we evaluate our
Tide-Energy potential?
Necessary equipment (1) bottle weighted so only
the neck is visible floating above the water
(2) a line to attach securely to the bottle (3)
a tape to measure the length of the line and
(4) an inexpensive digital watch with a
stopwatch feature.
1

2
3
4
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3. How can we evaluate our
Tide-Energy potential?

• How is the speed of the tidal current measured
  and calculated?
• From a fixed position
• (1) release the bottle into the current and
  
• (2) count the number of seconds until the
  bottle reaches the end of the line.
• Then calculate
• Length of the line in meters
• --------------------------------------
  meters per second
• Number of seconds

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3. How can we evaluate our
Tide-Energy potential?

• How many measurements of the speed of the tidal
  current are needed?
• Because the speed of the tidal current varies by
  day, week, and month, a number of measurements
  will be necessary to make an initial evaluation.
• To make an initial evaluation of the tidal
  current at a site, the speed of the current
  should be measured at least
• every 15 minutes during a tide cycle (12
  hours),
• once a week,
• for three months, beginning in either
  January, March, July, or September.
• That would mean 13 days of measuring, spread over
  3 months.
• Is that do-able for you?
• This would conclude Step 2.

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3. How can we evaluate our
Tide-Energy potential?

• With this information it should be possible make
  an initial evaluation of the Tide-Energy
  potential of the site.
• If one or more sites have sufficient Tide-Energy
  potential, then it might be of interest to you to
  proceed on to the next stage, that of a pilot
  project, not discussed here.

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Three main points

• 1) The capture of Tidal Energy using helical
  turbine technology can be done in a simple,
  inexpensive way, using much local labor,
  material, and equipment.
• 2) But, before attempting to implement
  Tide-Energy technology, each Tide-Energy site
  must be evaluated in terms of
• its location and accessibility in relation to
  users
• the speed, duration, and frequency of tidal
  current at the site.
• 3) This initial evaluation can be done
  inexpensively in just a few months, using local
  labor and resources.

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4. Can we get technical assistance
to make an initial evaluation?
Yes. Insofar as my time allows, I would be
pleased to assist (via e-mail) anyone interested
in making initial Tide-Energy site
evaluations. There would be no charge for this.
Good Luck. Scott Anderson
sdand_at_bellsouth.net 1 [phone] / 1
[phone] (mobile)