Tidal Power works....but has severe limitations.
Catch The Wave.
Tidal Power Generation.
The Annapolis Tidal Generating Station was completed in 1984. It was a pilot project sponsored by the provincial and federal governments designed to explore the potential of harnessing energy from the sea.
Annapolis Tidal utilizes the sea water of the Bay of Fundy. Tides, which can sometimes reach 21 feet in height, rise and fall every 12 hours and 25 minutes in harmony with the gravitational forces of the Sun, the Earth, and the Moon.
Annapolis Tidal Generating Station
Annapolis Tidal Generating Station
2004 Visitor Centre Hours
Daily: 10:00 am - 5:45 pm
May 16 - Oct 15
For information contact the Annapolis Royal Visitor Information & Tidal Exhibit Center
(902)532-5454
(
www.annapolisroyal.com/)
This facility has the distinction of being the first and only modern tidal plant in North America. The station is located in Annapolis Royal by the Bay of Fundy, home of the world's highest tides. Twice a day, the tide comes in and out. Twice a day the turbine turns. Twice a day electricity is generated which is supplied to the provincial electric grid.
Annapolis uses the largest straflo turbine in the world to produce more than 30 million kilowatt hours per year - enough to power 4,000 homes.
Annapolis is one of three tidal power plants in the world. The largest plant is located in France, in the estuary of La Rance near St. Malo. With a capacity of 240 megawatts, it generates on the incoming and outgoing tide. The output capacity of Annapolis Tidal is 20 megawatts. The smallest tidal plant is located at Kislaya Guba on the White Sea in Russia. It has a 0.5 megawatt capacity.
The future of tidal power generation.
The operating experience of the Annapolis Tidal Generating Station has proven that the straflo turbine technology is sound with few modifications.
The potential for electrical generation in the Bay of Fundy is enormous. Large tidal plants in the Minas Basin and the Cumberland Basin could generate more electricity than is currently produced in Nova Scotia. However, the environmental impact of the huge barrages could be far-reaching. Further studies, for example, would be required to determine the possible impact of these barrages on the tides along the eastern seabord.
Some day the tides of the Bay of Fundy may be seen as the preferred source of energy. For the moment, however, large scale tidal power is not yet economically and environmentally viable.
How does Tidal Power Generation work?
Single-effect turbines generate electricity only when the flow of water is towards the sea. This is how the huge four-blade propeller turbine or "runner" works, generating up to 20 megawatts at peak output. As the runner turns, the rotors' magnets sweep past the wire coils in the stator creating an electromagnetic current which is tapped and converted into useable electricity at a nearby substation.
The electricity is then transmitted down the line and distributed to homes and businesses.
http://www.nspower.ca/AboutUs/OurBus...idalPower.html
Solar is the key for now...in my opinion.
Solar Steam Turbine, Examining the Curnutt Solar Furnace
February 25, 2004
Introduction
Last month we set the agenda for this year's work -- solar steam to turbine-electric power. I'd like to remind everyone that the purpose of this club is to inspire innovation in key areas of growth in the 21st century. It is absolutely necessary for all of us to develop real alternatives to overpriced sources of energy so we can regain control over our lives. As long as unregulated utility companies are allowed to gouge the general public, we'll never be free.
As founders and directors of the Global Motive Power Revolution, my small staff can set the tone & direction of the revolution from centralized utilities; it is up to all of our members to experiment and share what they discover.
Overview of the Curnutt Solar Furnace
Curnutt solar furnaceThis month we are going to take a look at the first of two solar reflector designs -- the Curnutt solar furnace. Basically this design uses an array of (100) 12" x 12" flat glass mirrors all tilted to focus solar energy to a point approximately 12 feet from east to west, and azimuth adjusted to account for seasonal changes in the sun's (north-south) path.
Charles Curnutt first developed this system in the late 1970's in 29 Palms, California for the same reasons we initiated this club effort -- to break the stranglehold of the government-big biz energy cartell, through decentralizing energy production. Charles' solar furnace design was first published in Mother Earth News magazine in their July/August 1978 issue, with further developments printed in January/February 1979, and finally in their Autumn 1980 "Guide to Home Energy".
After seeing Charles Curnutt's solar furnace in operation and producing electric power from a homemade piston steam engine-alternator arrangement, Mother Earth News staffers designed and built their own unit. Their results were quite impressive.
From a 10 ft. x 10 ft. array of mirrors, they reached temperatures of 1600 degrees (F) at the focal point, and produced about 6,000 watts of power.
In one test session they reached 300 psi of steam pressure! Normally, operating pressures are in the neighborhood of 80 to 100 psi, depending on the water inlet pressure. Pressures as low as 60-70 psi are usable with a disk turbine -- however, the higher the pressure and fluid flow, the greater the power.
Mount Construction
solar furnace construction - hole in ground
hole in ground hole with girder
hole with girder girder with cement
girder with cement
post on girder
post mount
mount cross arm
cross arm
The first thing to keep in mind with a solar tracking system is that the reflector must rotate from east to west on a substantial mount with a clear, unobstructed view southward.
The ground portion of the mount we have used in the past for our dish systems consists of either a heavy duty I-beam or 6-inch steel tube cemented into the ground with a couple yards of concrete. It's important to make sure that the concrete mass is sufficient for counteracting wind loading. A typical wind load on an 8-10 foot reflector at 60 mph is around 3,000 pounds.
The I-beam or steel tube may extend some 5-6 feet above ground, or may be capped with a 0.5-inch plate just above ground -- ready for bolt-on extension. Make sure the steel section is perfectly level, before the cement begins to set up.
On top of the steel post is the mount which holds the reflector array and allows it to rotate east to west. The mount must be lined up with the North Star, so make sure it is built with rotational adjustment in mind.
Reflector Frame
Next is the reflector frame. This frame does two things:
bullet holds the mirrors and steam generator head
bullet rotates on the mount to track the sun
reflector frame on mount
reflector frame mirrors on frame
mirrors on frame
The reflector frame is essentially a 10 ft. x 10 ft. square steel frame with eight vertical or horizontal legs positioned just slightly over 12 inches apart. One hundred (100) mirror holders are welded to the ten vertical/horizontal legs. The mirror holders must allow movement in two planes so they can be aligned to focus on the steam generator head.
with steam head
with generator head
The steam generator head is a steel heat exchanger, about 18" x 18" -- similar to a car/truck heater core. Pipe supports for the steam head can either run up the center or from the corners, both to support the steam head and to feed water/steam to and from the head.
tracking actuator
with actuator
Finally, a tracking actuator is attached to both the rigid post/mount and the swinging frame.
That about wraps up the basics of this Curnutt solar furnace. As we mentioned earlier, we are simply setting the course and direction of the project -- inspiring ideas for club members to act on. As with all of our projects, there are countless details in fabricating these systems. So let's get to work and see what can be accomplished this year.
Next month we are going to study a parabolic reflector design fabricted in FRP (fiberglass reinforced plastic). We intend to cover:
bullet basics of mould or plug construction
bullet FRP lay-up
bullet practical mount design
bullet reflective surfaces
Until then, let's hear from our other club members who undoubtedly have experience and practical knowledge in solar-to-steam technology.
http://www.phoenixnavigation.com/ptb...les/ptbc36.htm
there is a better design....I will research it later.