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 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
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?
Examine the map in the next slide and determine if your country is in or along a red areawhere there is more intense Tidal Energy.
If that is the case, you may have Tide-Energy potential that can be evaluated easily and inexpensively.
On the map below, determine if your country is in or along a red area.
Red areas in the ocean have more intense Tidal Energy.
The worldwide distributionof 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.
These countries can receive significant benefits from Tidal Energy:
Yes, with a helical turbine.
Schematic view of a standard, 3-blade Gorlov helical turbine mounted in a frame with a generator
Operation of the helical turbine:
1.5 meters per second
In addition, the faster the current, the more energy that can be captured.
This is very important !
But, does it work well?
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.”
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.
A complete helical turbine generating system
(c) automotive alternator to charge batteries
(b) drive shaft, pulley, and belt
(a) special 6-blade helical turbine
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
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.
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:
because of the need to transport batteries to the site to be recharged.
How can we select the better Tide-Energy sites?
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.
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.
(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.
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.
Length of the line in meters
-------------------------------------- = meters per second
Number of seconds
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.
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.
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:
3) This initial evaluation can be done inexpensively in just a few months, using local labor and resources.
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.
+1 (352) 376-0799 / +1 (352) 246-8246 (mobile)