8 replies to this topic

[E3 wise]

EASTPORT, Maine, 3/5/12  -- The Federal Energy Regulatory Commission has approved plans for a 300-KW tidal energy project near Maine's Cobscook Bay, according to members of the state's congressional delegation.

The permit will allow Portland-based Ocean Renewable Power Company to install turbine generator units on the ocean floor and operate the project for eight years.
The company says it has been engineering and field-testing its turbines in waters off Eastport since 2004 and now wants to install five turbines within a 61-acre area between Goose Island and Grove Point. Each of the units is 98-feet wide and 31-feet tall.

Ocean Renewable Power says it could begin construction of the plant as early as March 2012, adding to the list of wave power plants recently approved by FERC.

A 1.05-MW project in New York's East River was approved in January 2012.

[artistry]

This is very interesting. It seems tricky to be installing the turbines on the ocean floor and they stay in place, as well as generate energy.The testing must have been effective, as they received approval and are going forward. This is very progressive and exciting to hear. I would rather hear about this type of project, than to hear about more nuclear plants. Thanks for the post.

[E3 wise]

Artistry

Here is a link to the company that shoes the technology being used.  I have no professional affliation with the company, that said I really like the technology and have been following the company for about five years. http://orpc.co/orpcp...owersystem.aspx  they also have designs for other applications such as rivers and tidel basin's

[still learning]

artistry, on 06 March 2012 - 07:19 PM, said:

.... than to hear about more nuclear plants. Thanks for the post.

Look at the amount of electricity to be generated..
The rated capacity for this tidal electricity proposal is 300 kilowatts.
Don't onshore wind turbines now run to 1 megawatt or higher?
Nuclear powerplants now run to gigawatt sizes.

Then there is the load factor, maybe 25% for wind and 80% for nuclear and something not released for tidal.

It's good to see that this project is getting started.  Maybe something significant will come of it.
Tidal electricity is something that may turn out to be worthwhile in a wide sense, but I have my doubts.  I wouldn't be surprised if it is a good idea in favored locations, where the tides and the geography/topography is right, but I kind of doubt that it'll be all that useful along most coastlines.  We'll see.

[artistry]

E-3, thanks for providing the link, for the additional information. I appreciate it. I had not heard anything about this method, until I read your post. The article answered one of my questions about movement on the oceam floor. There are modules which are moored to the ocean floor. Thanks again. Cheers.

[Sarah C.]

I was wondering how much power this would produce. It sounds like it will not produce massive amounts of power. Perhaps, since it is an experiment, it is not designed to produce massive amounts. I would hope this is true.

[jasserEnv]

In comparison to technologies that use wave power, this technology doesn't seem to be a great way to generate power given the short duration of water movement as the tides change. Like coal plants that site idle and are used only to meet peak load, these turbines will also be idle most of the time meaning that their operating costs will be higher. At the same time, the timing of the tides won't necessarily align with peak electricity usage meaning this captured energy needs to be stored and this will result in additional losses. It just doesn't seem like a great use of technology.

[still learning]

jasserEnv, on 08 March 2012 - 08:53 PM, said:

In comparison to technologies that use wave power, this technology doesn't seem to be a great way to generate power given the short duration of water movement as the tides change. Like coal plants that site idle and are used only to meet peak load......

I take it you don't live near the ocean.
Tides don't have a "short duration of water movement," that's not the way they work.  Contrariwise, tidal movements only stop four times a day ("slack water") , once at each low tide, once at each high tide.  Lots of speeding up and slowing down, only a little time stopped.  http://en.wikipedia.org/wiki/Tide

On thing about tides, they are predictable.  Should make the sale of produced electricity easier.
Whie I have my doubts about how practical tidal energy is, mainly because of the construction costs of building underwater and the maintance costs associated with saltwater corrosion and "marine fouling" (stuff grows on anything underwater,  all sorts of creatures looking for a place to settle down and grow), we'll see.  Hope my doubts are unfounded, that it's a great success.

Waves are unpredictable, so wave produced electricity would also be somewhat unpredictable.  While there's pretty much always waves in the ocean, sure, but wave height varies a lot, essentially unpredictably
I have even greater doubts about the practicality of wave produced electricity than I do about tidal electricity.  Same construction and maintainance difficulties with extra unpredictibility.

Idle coal plants, used only for peak load?  Hm.  Don't think I've heard that one.  Has it happened?  I didn't think coalfired steam turbine plants were exactlt "happy" about being shutdown, takes a long time to safely shut them down and a long time to safely restart too.  There are modern natural gas fired gas turbine electricity powerplants that are designed for "peaking" purposes, thought those were the ones that were expected to fill in the gaps.

[E3 wise]

These are all good questions let me fill in a few blanks.  First, this is a Second Phase Testing project in preparation for follow up large scale instillation.  Meaning that a small scale will be tested much like they did in New York for the Hudson River water turbine project.  This includes study of ecological and environmental impacts with a review process for the state and federal governments.
That said 300 KW is small the average home uses between 12 to 20 KW depending on location, size and efficiency, so this is enough for around 15 homes.

  A small start yes, but like wind which stated small at 100 KW almost 30 years ago,  this can be scaled up to much larger sizes. Likewise, Still Learning is absolutely right in that ocean and tidal is much less variable than wind, in other words much more predictable.

The company website is http://orpc.co/orpcp...owersystem.aspx  there are three different designs for river, tidal and ocean applications.  The ocean design is being studied for the Gulf Steam off Florida right now and I got to say from some background research I have been doing It looks exciting, We will see.  Hope this helps but also check out the company’s website.