What do you give to a U.S. State for a holiday present? How about a new high speed train line or two, a decent sized array of tidal turbines for Long Island Sound, or maybe factories that make products that are useful and in demand and which replace foreign imports? Or, if you don't like that state, perhaps a lump of coal in the form of a new nuclear reactor (which has to be paid for by the residents of the state)? Or maybe even more mass unemployment on top of the really bad unemployment that we already have in NY? Or maybe two lumps of coal in the form of even more grabs for the money made in NY by those numerous welfare queen red states which somehow get more money spent in them by the Federal government than is taken out in taxes, while NY State bleeds out at least $20 billion/yr to those "Red (welfare) Queen" states like Iowa, Nebraska, Wyoming and Alaska?
But, ever since George Bu$h got selected as President, "mean" has been the main refrain by much of America (the "Heartland", like we have no cardiac activity in NY State) towards NY's people, as well as by a lot of NY Republicans and wealthier types towards the vast majority of NY's less wealthy citizens. No doubt in some cases this ire and resentment may be deserved (Carl Paladino, Pedro Espada, Hiram Monsarate, Joe Bruno... actually, it could be a pretty long list). But it seems like NY State in general and the vast majority of its people in particular just can't catch a break, especially with things like falling median real income and a rising real cost of living for most people (oil, college education, health care and food prices), even though most of those items do not count towards the "overall cost of living". We've even been told we have wimpy renewable energy resources, and that to maintain energy supplies we need to invest in other places (the Canadian Maritimes provinces, Quebec, the U.S. Great Plains States) to get our renewable, non-polluting electricity and/or have NY installed nukes (16 new ones according to one of the NY Climate Plan options) for "homegrown" electricity. The proverbial "River of Slime" (Ghostbusters 2 - http://ghostbusters.wikia.com/wiki/Psychomagnotheric_Slime), a stream of "negative energy" that feeds off of the misery of many and in turn increases their susceptibility to do bad things/think bad thoughts (autocatalytic evil) just never seems to end...
So, here's a discussion of a very positive trend - something with the capacity to make NY a much nicer place. Like provide us with jobs, homegrown renewable energy at affordable prices, and a way to avoid the massive export of money for energy imports to NY (from other states, from other countries). This can be done with/via Low Wind Speed (wind) Turbines (alias LWST), which have only recently been commercialized, and are now sold by two companies in the U.S. (and made by one of them in the U.S.) - Vestas (made in Colorado) and RE Power. There will be other companies joining in on the fun (= major market opportunity) in the very near future, and a few shades of them (very low speed, low speed, medium low speed, medium speed) that can be tailored to a given wind resource will be marketed and sold in large quantities throughout much of the western world (Europe, USA).
And while these LWST may not drop the cost to produce pollution-less electricity, they vastly increase the area of land on which electricity can be made at reasonable costs - especially in places like NY State. For some fast wind states like Nebraska and Minnesota, LWST are largely irrelevant, since there is so much fast wind speed land area that can vastly over-produce electricity for such states. And while exports of some of that electricity can be done (on "wind plantations"), it turns out that by the time that Great Plains electricity is delivered to markets where people live, it is probably cheaper just to make most of that electricity near where it would be consumed using LWST units. It certainly makes more economic sense to make, install and operate those LWST in more populated, low wind speed regions - at least for the people living in those regions. After all, local manufacturing, local service jobs land lease payments, local property taxes/PILOT payments and local grid improvements (more manufacturing and construction jobs, etc). But whether economic sense will prevail is another matter altogether.
So, cheer up, NY, if only until the Republican's take over control of the U.S. House of Representatives in early January of 2011. The LWST phenomena is about to hit our state/the NE part of the U.S., and there is a lot of potential to do good by ourselves, and our planet. It's sort of like a Christmas (or choose your religious/lack of religious happy day) present for NY State. And given recent events and recent trends, it's about time something nice happened around here.
Discussion
The secret behind a LWST versus a "regular" or or a high wind speed turbine is really not all that mysterious. In order to tap faster winds at any given site, one way to do this is to increase the height above the ground where the winds are tapped (i.e use a taller tower). Similarly, to obtain a larger quantity of energy from a given wind speed (i.e. from a specified site and height), the best way to do this is to increase the size of the rotor blade (which is the same as increasing the swept rotor area) for a given generator size. A bigger blade and taller tower also go together very nicely, since wind speeds near the ground (as encountered by a blade at the bottom part of its rotation) are both more turbulent and slower than those at the top part of the rotor circle. To complete the picture, the wind turbine is customized for low to moderate wind speeds, and set to ignore some wind speeds which are more common at high wind speed locations (i.e. have a wind speed cut-off of 20 m/s instead of 25 to 30 m/s). Once this is done, the manufacturer has to figure out how to manufacture this system at a reasonable price. A LWST will cost more to buy and install than a Medium Wind Speed Turbine (MWST) for a given rated capacity, and in turn a MWST will cost more than a High Wind Speed Turbine (HWST) for a given capacity, but the cost of the product of these turbines (the electricity) can actually be lower for the higher cost unit - it all depends on the available wind resource.
Math-wise, the power extractable by a wind turbine is proportional to the cube of the wind speed, the square of the rotor diameter and the wind speed increases logarithmically with the height. A big blade on a short tower will spend a lot of its time in low power regions of the "rotor circle", which is also not good for power and energy production. But a big blade that is mostly exposed to a faster wind is good for power production. This is why LWST units tend to use taller towers than corresponding fast or medium wind speed turbines.
Because the power in moving wind rises so steeply with the increase in wind speed, wind turbines tend to be less efficient at capturing energy as the wind speed goes past some value (depends on the turbine model), and when winds are too fast, the units go into a stop mode, with the rotor blades pitched so that they don't move. For most commercial units, the cut-off speed is near 25 m/s, though for LWST units it is near 20 m/s. The ratio of the cut-out speed (between 20 to 25 m/s) and the cut-out speed speed (3 to 4 m/s) is between 6.67 to 6.25, but the ratio in power tapped (at cut-out speed to cut-in speed) is between 296 and 244 to 1. In general, really fast wind speeds don't happen that often, especially in low wind speed regions. If turbines did not "shed" efficiency as wind speeds get faster past some optimal point or have a cut-out speed, those rare but quantifiable high wind speed events would tear the unit to pieces.
For example, consider a location like the Lakota Sioux reservation in South Dakota - one of the windier places in the U.S., with wind speeds 60 meters above the ground often averaging 8.5 meters/second (m/s). Then consider SUNY Buffalo's Amherst campus, where wind speeds at 60 meters above the ground average 5.8 m/s. A fast wind speed turbine like GE's 1.5 MW unit with 70 meter rotor diameter and a 60 meter tower could easily get an average power output of 40% to 45% of rated capacity on those Lakota lands, but that same turbine would be hard-pressed to get 20% of rated output at the SUNY Buffalo Amherst Reservation. But, put a turbine designed for the slower winds (like the SUNY Buffalo Amherst Reservation), and such a unit could average nearly 30% to 35% of its rated output.
In the 2010 US wind Map, estimates were made of the available wind power that could be expected to be produced for each state - NY's can be found in this graph: http://www.windpoweringamerica.gov/images/windmaps/ny_wind_potential_chart.jpg. Note: some of the raw numbers for some wind speeds can be seen in tabular form at http://www.windpoweringamerica.gov/pdfs/wind_maps/wind_potential.pdf. This graph allows one to estimate the installed wind turbine capacity for NY at a given net output for a standard wind turbine model, which approximates a GE 1.5 MW x 77 (1.5 sl model) meter rotor diameter unit (now the most popular one in the U.S., or at least the model most often installed in the U.S.). For example, at a 25% capacity rating, 67 GW worth of wind turbines (or about 45,000 of them) could theoretically be installed on 80 meter towers and still meet the criteria used in this wind model (lots of them, see http://www.windpoweringamerica.gov/pdfs/wind_maps/wind_potential.pdf). The average output would be about 16,750 MW, or about the same as NY's present average electrical usage (about 16 GW = 16,000 MW). At a 100 meter tower height, NY's installed capacity would be about 113 GW, equal to about 34 GW on a delivered basis, or about twice NY's non-hydroelectric average demand.
In Figure 1, this curve is numerically simulated, but with the range extended down to the 20% net output level (commonly used in Germany, very rare in the U.S., as we have vastly superior wind resources, more land and cheaper electricity prices, which means that low wind speed sites are rarely used to make wind derived electricity). NOTE - this is just a math projection of the existing data points, and probably can't be extended too much further. This extrapolation corresponds to an estimate of between 21% (80 m height) to 29% (100 m height) of NY's land area available for a minimum allowable 20% (MWST) wind turbine net output or more.
Figure 1As can be seen, there is a considerable difference in the delivered output (= wind turbine capacity multiplied by the % net output) at the 25% net output levels for a GE 1.5 sl wind turbine. Just by using towers that are 20 meters taller, the rated capacity increases from 67,000 MW (67 GW) to 113 GW, and the average delivered power output would increase from about 16 GW (present average NY consumption level) to nearly 34 GW.
In Figure 2, the use of a wind turbine more attuned to lower wind speeds is shown (in this case, a Vestas V100 x 1.8 MW unit (100 meter rotor diameter) is compared to the GE 1.5 sl unit. Due to the larger size of these turbines, they cannot be placed as close together as the smaller GE units (77 meter rotor diameters). As can be seen, the LWST achieves a higher percentage use at a given wind speed, notably at the lower wind speeds, or the same net output but at lower wind speeds. And since the rated capacity of the V100 unit is 1.2 times greater than that of the GE unit, much lower wind speeds can result in the same average power output. (Note: the V100 comes with an option of an 80, 95 or 119 meter tall tower; the wind speeds at 95 meters are very similar to those at 100 meters above the ground).
Figure 2The wind speed/percent capacity relationship of a normal turbine (GE 1.5sl in this example) vs. a LWST unit (the V100 in this case) is shown in Figure 3:
Figure 3The LWST option allows the use of much more potential area in NY to economically generate electricity. For example, the GE units, if 100 meter tower heights were generally used, could be used at net output levels of 25% or more across 9.2% of NY, where average wind speeds are at least 6.1 m/s at a 100 meter height (about 75,00 potential sites). Average wind speeds required to produce a 25% net output with the Vestas V100 are only 5.3 m/s. And while this does not sound like much of a change (only a 15% change), this LWST could provide a 25% net output using wind speeds with only 67% of the power as comparable ones would be for the GE 1.5 sl turbines.
In the 2010 US Wind Map, the estimated wind power density was given as 5 MW of wind turbine capacity per square kilometer (km^2), and this holds regardless of the size/rated capacity of the unit, assuming a roughly similar rotor size to generator capacity. This correction factor for the Vesas V100 and the GE 1.5sl units needs to be kept in mind (0.77).
When the wind turbine capacity is converted to usable land area, the following relationship for the GE unit can be seen (Figure 4). This also allows the wind speed versus allowable land area relationship to be estimated without the proprietary GIS data used for the 2010 US Wind Map.
Figure 4The estimated usable area listed for the US Wind Map for NY was 22,587 km^2 at a 25% capacity, and 11,610 km^2 at a 30% rated output. Estimating this down to the 20% rated output level (with hub height wind speeds at 100 meters averaging 5.64 m/s) gives a value of 34,671 km^2 of usable land surface, or about 29% of NY State land. Note: this also includes provisions to exclude parkland, steep slopes and many urban areas. And it also does not mean that turbines would be placed at a density of 5 MW capacity per km^2 on all 34,671 km^2 (about 13,543 square miles).
Using these areas (29% of NY State) as potential places for commercial scale wind turbines but using LWST units instead of medium wind speed turbines, the following relationship develops:
Figure 5As can be seen, LWST units have much higher net outputs at the low wind speeds that much of NY's usable lands have as a wind resource. As a result, there is more potential for electrical energy production using LWST, and this is shown in Figure 6:
Figure 6(Note: dots are in the "middle" of "wind bins"; numbers correspond to minimum wind speed for that "wind bin" corresponding to 2.5% of net wind turbine output).
It turns out that using the GE turbines with 100 m tall towers and at average wind speeds of 5.64 m/s (20% net output) would provide a potential of 47.1 GW of electricity on a delivered basis. Since NY has an average need for 13 GW of non-hydro power (plus 3 GW of hydro/biomass), there is plenty of potential to replace all of NY's pollution derived electricity (gas, oil, coal, nukes) just using these medium wind speed units, or roughly 3.6 times the present need. However, switching to LWST units, the NY State delivered electricity potential is 62.6 GW, or roughly 4.8 times the present need.
It also turns out that LWST are less expensive to operate when average wind speeds are less than 6.7 m/s, based on an installed cost for the GE unit of $3 million ($2 million/MW capacity) versus $4.5 million for the V100 ($2.5 million/MW capacity). This is shown in Figure 7:

Figure 7
While these cost numbers ($100/MW-hr = 10 c/kw-hr) may seem high, that is due to the "unsubsidized" term - where all tax avoidance and other incentives (such as NY's Renewable Portfolio (RPS) incentive) are NOT included. With the NY RPS, the subsidies for a V100 operating at a site with a 6.6 m/s average wind speed at hub height would amount to nearly $5 million ($200,000 more than the installed cost of the unit) during the initial 10 years of operation; over a 20 year period, these would average at least $250,000 annually (much more when the time value of money is included), or $41/MW-hr, dropping the needed break even electricity price to near $51/MW-hr. Obviously, a higher price would be needed to provide a reasonable profit to the owner, so required electricity prices of at least 6 c/kw-hr ($60/MW-hr) would be needed as long as these subsidies are maintained; without them, a price of near $100/MW-hr (10 c/kw-hr) would be needed.
The 10 c/kw-hr to 12.5 c/kw-hr unsubsidized price needed for LWST is actually much less than UNSUBSIDIZED costs of coal, oil, old nukes and most especially new nukes. As for natural gas sourced electricity (assuming the marginal price needed for new gas (about $10/MBtu) is employed), fuel prices equating to $83/MW-hr need to be added to CO2 pollution costs of about $35/MW-hr, resulting in a price of $118/MW-hr that represents a viable break even price. However, natural gas prices are presently averaging about $4.50/MBtu (well below the price needed to justify new exploration and production activity), and are notoriously fickle, and natural gas prices have become completely disconnected from oil prices on a thermal basis. And at present there is effectively no price paid for dumping CO2 pollution into our atmosphere. Trying to relate a long term electricity price to short term natural gas prices is just plain meaningless....
Conclusion
Of course, the electricity production capacity only has to be as large as electricity consumption (and this consumption term also includes the losses incurred by electrical energy storage via pumped hydroelectric systems, and other marginal energy storage systems). For land based systems, NY State only requires about 10 GW on a delivered basis for land-based wind turbines. When added to the existing 3 GW of hydroelectric/biomass, as well as the potential of 2 GW of tidal and anywhere from 2 to 10 GW offshore based turbines, all of NY's electricity could be supplied, in the aggregate, without CO2 or "rad-waste" pollution. Of these "new" renewable systems, the onshore wind turbines would be the lowest cost approach.
10 GW on a delivered basis of land based wind turbines is about 25 to 36 GW of rated capacity for LWST (depends where they are placed). This would be around 14,000 to 20,000 wind turbines of this variety, or about one turbine per two to one per three square miles. However, this would translate into large regions with no turbines and some regions of a more concentrated nature. For example, this could be arranged as 1600 square miles (3.4% of NY's land area) where the wind turbines are placed at 12.5 MW capacity per square mile (about 7 V100's per square mile).
And then there is the NY Climate Plan(s). Even at their most green form (and that is not much), only 1.85 GW (delivered basis) of wind derived electricity is planned. That is less than 5.5% of NY's "MWST" capacity (similar to the GE 1.5sl) where the 25% minimum capacity is employed, or less than 4% of the "20% or greater" MWST capacity. That (4% to 5.5%) is not exactly straining the capacity limits of NY using commonly implemented wind turbines - NY State has over 500 of the GE 1.5 sl units already operating.
But, the cowardly approach of NY's Climate Plans become even more evident when LWST units are examined. After all, 1.85 GW is only 3% of the 62.6+ GW (delivered basis) that could be made using LWST at costs vastly less than new nukes or PV systems, and at about 50% less than the cost of offshore wind units. A whole 3% of NY's on-land wind turbine capacity - whoopee!
One thing should be quite apparent with regards to those NY Climate Plans - they seriously did not even try to employ wind turbines to take the pollution (CO2 and nuclear waste) out of NY's generation capacity. Coming up with 10 GW on a delivered basis should be no problem at all - that would use only 16% of NY's windy lands, which are only 29% of NY's total land area (total of less than 5% on NY's land area would have a turbine in sight). And this would provide something like 1 million job-years of employment, much of which could be captured by NY with this $74 billion capital improvement to the state over a 20 year time frame. Those in charge of the Climate Plans just never bothered to go Green, sufficiently, at even a fraction of our state's capacity. Odds are they were overly concerned with keeping electricity prices low, in spite of the fact that any use of fossil fuels even a decade from now would be economically foolish, due to their high cost, as well as the FACT that predicting future prices is a poor crapshoot, at best, and a bad bet if the wrong assumptions (like there will be plentiful low priced fossil fuels available...).
And if you don't use it (the Green Energy Approach), well, you lose a major chance at economically revitalizing the state. Instead, the only significant source of income will be that which can be stolen from within the state and from outside the state by Banksters and their friends in the Finance, Insurance and Real Estate businesses. And we probably only have one other massive fraud-fest similar to the mortgage mess of 2002-2008 before the rest of the world wises up and decides to go gamble at some other casino. So it would be nice if our leaders wise up.. Meanwhile, places like Quebec and Ontario will be "eating our proverbial lunch" as their systems allow wind turbine derived electricity to be priced at a level that justifies such investments.
But, sometimes our leaders can be our own worst enemies. And that would be unfortunate at the current time due to the fragility of our economy in the aftermath/continuation of the Great Recession of 2007-2010 and the official arrival (as announced by the International Energy Agency) of Peak Oil.
DB

