Tidal Energy

Anyone who has been caught in a nasty undercurrent knows the power of the tides. And just as windmills can covert the physical energy in a breeze into electricity, tidal turbines can do the same for the motion in the ocean. The engineering principle is no different — the steady currents found in coastal of water like Canada's Bay of Fundy turn the rotors of an underwater turbine. But tidal streams are far more predictable than wind, which means utilities using tidal don't have to worry about unexpected still days. The cost of putting equipment under water and concerns about the impact on the marine environment have kept tidal experimental, but that's beginning to change. Verdant Power recently completed a successful trial in New York City's East River, and the UK-based Marine Current Turbines is preparing for a 10.5 MW project off the coast of Wales.

[Sparty]

Could you tell us some more about Scotland's wave and tidal energy. I gather that the Scottish coast has a large tidal range that should be quite a powerful driving force?

[Alite]

Tidal energy is valuable for a few. Of course tidal energy should be used. But tell me this, what proportion of energy should be based on tidal?
Ro

[Alite]

Tidal energy is limited to specific locations. It is a great energy source that should be used but is not available to most cities and so can only be small part of the energy solution. Wave power is more prevalent

[Sparty]

I find both concepts to be interesting.

As I understand it Tidal requires quite a large range from high to low tide.. several meters or more. I remember seeing a world map with that data published in the early 80's.

Current energy is also interesting -we had a brief trial of that here on the Gold Coast but it didn't seem to progress.

Wave power is a strong contender as the story below outlines... and once again Australia is at the forefront of the science if not the economic wil to invest in it...

WESTERN Australia is set to become the site for Australia’s first ever commercial wave power project, with the expansion of the CETO wave technology to its next stage off Garden Island.
After months of negotiations, Carnegie Wave Energy recently secured a license from the State Government to install and operate a commercial scale, autonomous CETO wave energy device off Garden Island, aimed at demonstrating its performance capability for delivering energy.


Carnegie Chief Operating Officer Greg Allen says the company is moving through a clear process towards a large scale commercial operation.
“We’ve come through from the concept development, through proto-typing through the pilot phase at Fremantle. The first stage of the Garden Island deployment, which is the stage we’re currently in, is to deploy a single autonomous unit, that won’t be connected to land.
“It has an energy dissipation unit that’s attached to the side and will simulate the load on the unit. That’s the pre-cursor and the information from that will feed into the detailed design for the 5MW facility. That design work will happen throughout 2010 with construction of the next phase commencing 2011.”
The Garden Island stage will form part of Carnegie’s 5MW commercial demonstration project supported by $12.5m of State Government Low Emissions Energy Development (LEED) funding.
Mr Allen says the plans are to take it from a 5MW facility to a 20MW and finally a 50MW facility, with the projections for a 50MW wave energy facility comprised of CETO units indicating it could provide power at around $150 per megawatt hour.
“These stages will then give us the demonstrated performance of the unit, expanding the knowledge we already have from our Fremantle pilot plant, into deeper water and to a commercial scale.
“That will verify the costs of the total plant as well as the output for a whole system. At that point we have a technology that’s bankable; we know the costs, we know the output capability and we know the life expectancy.”
The CETO system comprises an array of submerged buoys tethered to seabed pump units. The buoys move in harmony with the motion of the passing waves, driving the pumps which in turn pressurise water that is delivered ashore via a pipeline.
High-pressure water is then used to drive hydroelectric turbines, generating zero-emission electricity.
Deployment of the first commercial scale, autonomous CETO wave energy unit will begin shortly with the installation of the unit’s mooring system.
Mr Allen says Carnegie has reached an agreement with local energy providers to ensure the on-sell of the power.
“We have a memorandum of understanding with Synergy to negotiate the off-take from the facility. We are also one of the shortlisted proponents for supply of power to the second desalination plant with WaterCorp.”

[Alite]

Sparty has said most of the numbers, all of which are compelling.
If an island nation like Australia does not take advantage of waves then the sahara should start selling ice blocks.

I hear that Carnegie has been snubbed by the government for a wave energy option that is above water, ugly, and so doomed to fail. No-one wants above water generators when below water generators do the same thing.

This is a clear case of government ... ... deciding to not do what is best for the local community but to go for the money.

I'd love to know who made this decision.

Alite

Why is tidal energy not promoted more and more widely used? Lack of interest or lack of funds? Or the result of the lobby of the oil industry?

Is tidal energy an alternative or are there too many obstacles?

Originally Posted by eric0224_yu

T tidal streams are far more predictable than wind, which means utilities using tidal don't have to worry about unexpected still days. The cost of putting equipment under water and concerns about the impact on the marine environment have kept tidal experimental, but that's beginning to change. Verdant Power recently completed a successful trial in New York City's East River, and the UK-based Marine Current Turbines is preparing for a 10.5 MW project off the coast of Wales.

Because of the massive size of the oceans, Tidal Power has great potential for future power and electricity generation . Although the energy supply is reliable and plentiful, converting it into useful electrical power is not easy. Another good thing for Tidal Energy is it's a largely untapped, renewable ENERGY source based on lunar gravitation rather than solar radiation.

I once rented a holiday house that was powered by a small stream. The owner had put in a 2.5 inch black poly pipe about 100 meters upstream at the top of the fall of about 45m. He then passed the water over a paddle wheel connected to a car transformer and this led to a bank of batteries.

There was enough power for a fridge and several low wattage lights.

I wonder if a bigger system could work?

I guess it already does as hydro-electric schemes but what about something in between?

Update:


"LucidPipe can operate across a wide range of flow conditions, volumes and velocities. The unique lift-based vertical axis spherical turbine design generates electricity by extracting excess head pressure from large diameter (24”-96”), gravity-fed water pipelines and effluent streams. To maximize electricity generation, several LucidPipe systems can be rapidly and easily installed into a single pipeline,* allowing operations to continue normally." More - http://www.lucidenergy.com/lucid-pipe/

Hello, Every one!!
I am new to this forum community, I am very glad to join this community and I want to share my ideas and knowledge with the forum members and increase my knowledge,
Thanks