Finavera is on the verge of getting its AquaBuOY wet, as it announces a new wave power project in British Columbia.
Vancouver's Finavera Renewables hasn't even gotten its AquaBuOY wet yet, but today it announced a new wave power project in British Columbia.
The company's AquaBuOY technology converts the vertical movement of waves into pressurized seawater by means of two-stroke hose pumps.
The pressurized seawater then moves a turbine, which drives an electric generator.
Check out the seagull-seducing animation here >>
The 70-foot high test buoy, which is under construction at Oregon Iron Works in Portland, is set to make its first splash into Makah Bay in Washington State later this month or in early September.
And it's not that big just for show.
"To be able to get the amount of power that we want we need to fill it with a lot of seawater," Finavera spokesman Myke Clark told Cleantech.com, adding "the final device will be bigger than that."
The Makah Bay test is expected to generate 1 megawatt, but other projects, including British Columbia, are shooting higher.
Finavera said the project in Ucluelet, B.C., which today received an Investigative Use Permit, would have an initial potential generating capacity of 5 MW, which Finavera said is enough electricity to power almost 2,000 homes.
But the company isn't stopping there. The Ucluelet project, off the west coast of Vancouver Island, has a planned expansion to 100 MW.
Finavera has 5 wave power sites in various stages of planning, two in the United States, one in Portugal, one in South Africa and the Ucluelet project in Canada (see Finavera wave energy project gets preliminary FERC nod).
Grabbing power by air as well as by sea, the company also has wind energy projects under development in Canada and Ireland.
At 70-feet, with a 13-foot diameter, the AquaBuOY is quite a bit larger than SRI International's test buoy (see Muscling the waves).
SRI is using a rubbery material that stretches and contracts with the waves to generate electricity.
SRI dropped its buoy, which doesn't look like it needs a tractor trailer to get around, into the waters off of St Petersburg, Fla., on Aug. 3.
We're not kidding about the tractor trailer >>
The AquaBuOY even dwarfs Verdant Power's 20-foot tall East River turbines in New York (see Verdant deploys tidal power array in New York).
Verdant uses tidal power generators, as opposed to Finavera and SRI's wave power systems, but while Verdant's turbine blades made it to the water before its competitors, it's been having its share of problems.
All six of the turbines have been shut down for repairs after taking some damage from the rougher-than-expected East River tides.
But Finavera's Clark said, "all of these technologies and projects are early stage, so you have to go through these growing pains."
"You have to put these in the water to see how these things come out, how they work," he said.
Getting them in the water takes some patience, as government approval has been slow in the past. But new rules at the U.S. Federal Energy Regulatory Commission are expected to speed things up (see Marine power companies applaud possible FERC changes).
"The project in Makah Bay, we've been in the permit process for about five years. It's a long time, but it's only because we were the first ones to do it," said Clark.
Clark said there's really no comparison when it comes to the permit process in the U.S. versus Canada.
"It's a bit of a slower process right now," he said of the company's home province. He noted that with the abundance of hydro power in British Columbia, "there's not that much need to look for other sources of energy."
"Our projects primarily are going to be focused on the West Coast of the U.S."
The company's already got a third project in works for the States, putting in an application for another preliminary permit in Northern California, just outside of Trinidad.
"That's another 100 MW project," he said. "It's a great population base for the energy there, and there's a willingness from the state government and the local government to get renewable energy up and running."
Water vs wind turbine blade structure
Verdant had the top 1/3 of its turbine blades sheared off by the power of the East River. The design of underwater turbine blades apparently was not of sufficient strength. Although water current turbine blades are only a fraction the diameter of wind turbine blades, the forces on these blades are perhaps 50 to 100 times greater due to the sheer mass of the water pushing against them.
The blades may be smaller in diameter and rotate at considerably lower rpm as compared to the wind type but the potential for energy conversion is just as great.
Let us examine kinetic energy. The formula is:
KE = 1/2 m v^2
Kinetic energy equals one half of the mass times the square of its velocity.
1. With wind energy, the mass is about 1/1000 the mass of liquids or solids of the same volume. Much of the energy is due to the velocity portion of the equation. In actual practice, the energy that can be practically converted rises with the cube and not the square of the velocity. There is a minimum start up wind velocity to get the blades moving and then also a second greater minimum velocity (cut-in speed) for the generator to start producing energy.
2. With ocean/river current flow, the mass being about 1000 times greater than air per unit volume means that Kinetic Energy derived from conversion of moving water becomes more mass than speed related.
If we were to compare the two energy sources,
1/2 m(air) x v^2 =
1/2 x 1000m(equal vol water) x v^2
we would then better be able to see that it is not necessary for the velocity of the water to be great in order to provide equitable Kinetic Energy. Actually, the volume of the water passing through the blades of the ocean turbine would have to be only a fraction of the volume needed for an equivalent amount of energy produced by a wind turbine. Thus the need for smaller diameter but much stronger blades for the ocean turbine.
adrianakau@aol.com
Good analysis
And science aside, putting turbines underwater also makes for far nicer aesthetics. Wind farms are an eyesore.
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