Slashdot Mirror
Floating Wind Turbine Platform
Sterling D. Allan writes "Inventor Tom Lee is nearly ready to strike a deal to install a flotilla of offshore wind turbines, combined with hydrogen-generating capability and battery storage, which he says will enable them to have the consistency needed to be a primary grid energy provider, and not just supplemental to the gird. The floating platform enables them to take the turbines to where the wind blows and birds are few, and people even fewer. His objective in commencing this project 12 years ago was to come up with a power solution for developing nations."
The electricity->hydrogen->electricity cycle is only about 50% efficient using utility-scale 100MW plants (slightly lower for 1MW or so sized plants, and much lower for lab-sized plants). Right now there is so little wind power installed that the grid can easily handle large amounts of extra wind power. When 20% of electricity is coming from wind, then they'll start to be substantial benefits to power storage (though I see hydroelectric storage as a more practical form of storage than hydrogen, and that's good until renewables cover 100% of electricity demand and we're at the stage of needing liquid fuel for airplanes and vehicles).
Second, I believe that using a floating platform with very tall (~400 feet or so) structures is asking for trouble. Something floating is far more vulnerable to storms than a securely grounded pile. There must be a good reason it's not being done now.
Thirdly, why have the things so far from shore. Transmission losses (if undersea cables are employed) are large over such distances, and it does take quite a bit of aluminum to make such long wires. If a ship must come to load the hydrogen every once in a while, then you just added a large operating expense (and one of the nice things about wind and solar is very low operating expenses).
So why not stick to tried and true near-shore and land based wind turbines?
Sigh ... disconnect cable, attach cable to buouy, raise anchor, tow platform away (or include propellers on platform to sail away). This is the same process used by oil rigs.
But of course nobody is protesting wind and solar power,
I can't take anything you write seriously.
You are so full of shit that you can't escape your own narrow-minded rhetoric.
The ones I've cited were just the first three entries.
"Rocky Rococo, at your cervix!"
Have you ever seen how big oil platforms are? BP's Thunder Horse is 112m wide, 136m long, and 130m high. It weighs 60,000 tons. GE's biggest turbines are 75m tall at the hub and weigh 300 tons. You could easily place one of these turbines at each of the four corners of Thunder Horse.
All the technology to build large and tall platforms, anchor them to the ocean floor, connect them under the sea to the land, disconnect them when a storm is coming so they can be moved out of the way, reconnect them, maintain them, etc. already exists in the oil platform industry.
These things probably are not as tall as oil platforms. They connect to land through cable which is relatively cheap to manufacture and install compared to pipelines which have to be carefully laid on the ocean floor and have to be designed not to leak oil all over the place. Living quarters would be drastically simpler because turbine maintenance takes many fewer workers than oil drilling (Thunder Horse has facilities for 229 workers to be stationed there semi-permanently). They don't need the same level of safety as oil rigs since they are not pumping and storing an environmentally sensitive substance. They don't need all the drilling and pumping equipment that oil rigs do (wind turbines are vastly less costly/complicated than oil rig equipment).
Can't comment on cost/return. Clearly if there's no return they won't get built, but the technology all exists and these things would be much, much cheaper than oil platforms.
While not an expert in the field, I know a guy who is, and from discussions with him, have gained some knowledge.
Wind turbines are more a 'feelgood' measure than a power generation system. They are, primarily, made from high grade Aluminium, which requires very high amounts of electric power to produce. How much? Well, you're average generator doesn't become energy positive for about 8-10 years. ( est. lifespan 20-35 ).
I would imagine that a floating turbine would require considerably more construction materials, so the maths becomes even worse, especially after taking into account the power transmission/storage requirements.
Like most forms of alternative energy, it's a good idea, but needs more work to be truely viable.
The U.S. Department of Energy's National Renewable Energy Laboratory did a feasibility study on these types of floating turbine farms and found that they could be built using existing technology and provide electricity at approximately $0.05/kWh. The turbines studied did not include the battery storage and hydrogen production described in the article above.
No "breakthrough" required for patents. You merely need to invent something new and non-obvious. An example I reference occassionally is a guy that invented a cam shaft that results in up to 3% more fuel efficiency. Its not a breakthrough, he just designed a slightly more efficient cam shaft.
Also, its not 45 patents, its 2 patents that include 45 claims. The number of claims in a patent is effectively meaningless. Its just the list of what the invention consists of. Also remember that this thing includes hydrogen generation, battery storage of the power and is self-propelled for moving out of the way of storms. There's plenty of places where someone could have come up with a better way to do something or other. Its not clear that you couldn't make off-shore floating wind turbines work without those patents, though.
I work in the wind energy industry and the above comments strike me as misinformed.
Wind turbines are not generally made from Aluminium. Towers are typically rolled steel, and blades are usually glass fibre or other composite construction. It was estimated some time ago that wind turbines became energy neutral in about four months, including manufacture, transport, construction and desposal. They are essentially extremely energy efficient generators. This is in sharp contrast to PV for example.
Lee (and the parent) assert that wind power does not constitute not serious generation. Denmark forms an excellent counter-example, approaching 30% wind energy penetration on windy days. They have the advantage of grid stabilisation from Germany, but even the UK government estimated that 20% penetration would pose no serious problems in grid stability terms.
As for (non-floating) offshore devices, the UK is gaining experience fast. Round 1 projects are in construction or operational, and round 2 are in planning. Several round 2 projects are rated around 1GW, equivalent to a large conventional power station, however, the economics are fairly tricky, even in areas unaffected by Lee's "Land Wind Shadow".
My personal feeling is that if battery technology or hydrogen conversion were economically viable, the vastly lower cost of on-shore construction would more than outweigh the additional wind speeds obtained off-shore, especially if the turbines were put on a hill. Power storage systems tend to be done on a smaller scale (one turbine and a backup generator) for island communities, but this is driven by the high price of energy in these locations.
Lee's design strikes me as perculiar:
1 Wake losses. turbines are usually placed atleast 6 rotor diameters downwind of each other in prevailing directions, to avoid onerous fatigue loads. Lee's machines are 1D apart.
2 Why have the battery storage off-shore? Could there not be a more efficient, and easier to maintain on-shore facility?
Where did you get THAT information from? Wind generators are steel (usually with fibreglass blades). The energy payback is around 6 months which is pretty damned good. Germany is already generating 12% of its power demands from your so called "feel good" measure.
But I'm not convinced the floating platform idea will work - tall, floating structure = asking for trouble.
Oolite: Elite-like game. For Mac, Linux and Windows
Have you ever seen how big oil platforms are? BP's Thunder Horse is 112m wide, 136m long, and 130m high. It weighs 60,000 tons. GE's biggest turbines are 75m tall at the hub and weigh 300 tons. You could easily place one of these turbines at each of the four corners of Thunder Horse.
Not really. Wind turbines need to be spaced at least 5 times the rotordiameter to be cost efficient. Primarily because of the wind shadow behind each turbine, but also because of the increased stress on rotor and tower from turbulent air. So a platform that could acommodate 4 turbines af the size you mention would have to be half a kilometer along each side.
//Wegge
Excerpt:
So to summarise (or paraphrase, if I get too verbose):