Category: Hydrokinetics
Tidal Energy – By Guest Blogger Anil – Continued
| February 20, 2010 | Posted by Anil under Hydrokinetics |
Continued from yesterday…..
Another drawback of tidal energy is the dependence on location for a successful project. As with most of other water based methods of energy generation, the location plays an essential role in harnessing the potential power source; site procurement costs gets high increasing the cost of the entire project.
Currently there are very few tidal power stations in the world. The largest and oldest is located in northern France at the La France river mouth estuary. The other sites suitable for the utilization of tidal power exist in many places around the world majorly in France, the United Kingdom, Former Soviet Union (now Russia), Canada, and the United States. Before setting up the plant, it is important to have a proper feasibility study.
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Tidal Energy – By Guest Blogger Anil
| February 19, 2010 | Posted by Anil under Hydrokinetics |
Water covers about 70 percent of our planet, majorly composed of the oceans with endless waves and perpetual tides. Water is a source that lays the foundation for many forms of renewable energies like Hydro energy, Ocean energy, Tidal energy and Wave energy. With the advent of newer renewable energy sources, water is heavily counted upon as the source of green energy. The major advantage of water based energy sources is that water can be harnessed to create energy with almost zero carbon emission.
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Hydrokinetics and the DoE
| December 5, 2009 | Posted by Craig Shields under Hydrokinetics |
We’ve seen a marked increase in the attention — and the funding — given to hydrokinetically-generated energy by the Obama Administration’s Department of Energy. Personally, I’m gratified by this; until recently, I had been concerned that this subject was being badly neglected; I’m glad to see this turnaround.
I happened to be working on my book on renewables yesterday, and had the good fortune to knock out the chapter on hydrokinetics, which is based on a talk with Dr. Brian Polagye at the University of Washington. Brian is part of the DoE’s Northwest National Marine Energy Research Center for Tidal Energy; I was referred to him by an expert on the subject at the Electric Power Research Institute (EPRI) who told me, “In my opinion, Dr. Polagye is the nation’s leading researcher on hydrokinetic energy.” Good enough for me!
A few highlights:
I think – or I guess I should say I thought – of hydrokinetic energy as being essentially constant. The sun doesn’t shine 24 hours a day, but rivers never stop flowing. Yet there are significant variations in the extractable power from flowing rivers. As I suppose I should have surmised, rivers, based on rainfall as they are, experience significant seasonal variations. And tidal currents, of course, have periods of relative calm in cycles during the day. So there is nothing unique about hydro as a renewable source from this perspective.
As I noted in the white paper I wrote on the subject last summer, those wishing to submerge power generating devices in the rivers or oceans — in the US, at least — face a considerable battle in terms of regulation. As an advocate for renewables, that rankles me — yet Brian helped me put this in perspective. According to what he told me, the DoE is far more involved in expediting approval for such projects now than they were when the original devices were developed — but it’s still not easy – nor should it be. “If both sides aren’t screaming, regulators probably aren’t doing their job,” he said. “Environmentalists should probably be concerned that regulators aren’t sufficiently aggressive in protecting aquatic ecosystems, and entrepreneurs in power companies should be yelling that regulators are too sheltering and too slow to grant approvals.”
When I asked for an example to illustrate the point, Brian replied, “Easy. I’m up here in Puget Sound. If I have a turbine in the water and an orca washes up with its belly cut open – even if that was really caused by a ship’s propeller, it would set this operation back a decade – if it wouldn’t kill it completely.”
For my money, the real issue with hydro is scale. The theoretical limit to the amount of hydrokinetic energy that can be generated in our rivers, for instance, is the potential energy of the water in the first place, i.e., the weight of that water times the vertical distance it will fall. That is, by reports I’ve seen, insufficient to generate more that a few percent of North America’s power needs. “That may be true on a continental basis,” Dr. Polagye agrees. “But on a regional basis, hydro can make an extremely significant contribution.”
Fascinating stuff. My sincere thanks to Brian for his time, and for the dedication that he and so many others make to such a wonderful cause.
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Hydrokinetics in the News
| October 11, 2009 | Posted by Craig Shields under Hydrokinetics |
Interest in the hydrokinetically-powered electric generator (HyPEG) is really heating up. I had numerous calls with potential investors late last week that show real promise.
Also, for the book on renewables that I hope to have published in January, I’ll be interviewing Dr. Brian L. Polagye, in the Department of Mechanical Engineering at the University of Washington. A colleague referred to him as “the nation’s leading researcher on hydrokinetic energy.” As I wrote back, I’m truly honored to have the good fortune for a conversation with a man of that stature; what a learning opportunity this will be.
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Hydrokinetically Powered Electric Generators
| September 25, 2009 | Posted by Craig Shields under Hydrokinetics |
Those of you who read my Three Brass Tacks article on hydrokinetics will remember the concept of the HyPEG (Hydrokinetically Powered Electric Generator). I’m thrilled to announce that we at HLK (Hydrokinetic Labs, LLC) made significant forward progress this week, where US Representative Geoff Davis (R-KY) recommended that the DoE take a hard look at funding and developing HyPEG technology.
It’s too early pop the champagne corks, but it’s certainly movement in the right direction.
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Hydrokinetics – Different Approaches
| September 25, 2009 | Posted by Craig Shields under Hydrokinetics |
I am by no means an expert in fluid dynamics or hydrokinetics more specifically, but I must say that I’m happy to be learning more every day about the opportunity that exists in extracting energy from the motion of earth’s rivers and oceans. Intrinsically, there is a lot to like there, since the vast majority of the sun’s energy that our planet absorbs goes into our waters, rather than our land masses and atmosphere. The challenge lies mostly in the fact that, though water is a far more dense fluid than air, it tends to be slow-moving – almost all of it under 3 knots.
In fact, this was my initially negative reaction to the concept of the HyPEG – if you’re taking kinetic energy from the river, isn’t the velocity of the water is far more important than the mass? The answer: Sort of. More relevant: The power of a rotating structure is its speed times its torque. And yes, in the HyPEG, that speed won’t be large, but the torque will be enormous. When the inventor quoted the figure (30 million foot-pounds), that shut me up really fast.
There are numerous other ways to overcome this challenge, however, and one of them is depicted in this video on a technology called vortex-induced velocity, which is under development at the University of Michigan. Note that things that swim do so by taking advantage of the density of the fluid, and using their bodies or tails to create temporary vortices of fast-moving water.
Though there are no cost figures mentioned in the video, to me, this sounds like an expensive solution. I should also note that it seems like a danger to aquatic life – a “sushi-maker” as they say — to describe submerged devices that that tend to chop up fish. Having said that, I have to applaud the creativity. Hey – may the best technology win.
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DoE Backs Hydrokinetics
| August 28, 2009 | Posted by Craig Shields under Hydrokinetics |
I’m always glad when readers write in to alert me to news items in renewables that I may have overlooked. Scott Ledgerwood writes:
Craig — enjoyed your hydrokinetics write-up. In case you missed this, see DOE notice on upcoming projects for Advanced Water Power Technologies; it specifically mentions hydrokinetics.
Thanks, Scott. I heard that the DoE received 3500 requests for grant money – obviously an order of magnitude or so more than they had anticipated. My partner with the HyPEG invention is busily applying for grant money to develop his idea, and I know he’ll be glad to see this. In particular, I note that that the Oak Ridge National Laboratory in Tennessee is evaluating turbine designs for fish-friendliness. As I’m sure you recall, that is one of the key features/benefits of the HyPEG.
Thanks again.
