Reality check on wind energy (Willem Post)

Aug 18, 2011

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Willem Post

Willem Post BSME (Bachelor of Science in Mechanical Engineering) New Jersey Institute of Technology, MSME (Masters of Science in Mechanical Engineering) Rensselaer Polytechnic Institute, MBA (Masters of Business Administration) University of Connecticut. P.E. Connecticut. Consulting Engineer and Project Manager. Performed feasibility studies, wrote master plans, and evaluated designs for air pollution control systems, power plants, and integrated energy systems for campus-style building complexes. Currently specializing in energy efficiency in buildings.

Contact:  wilpost@aol.com

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Willem Post, Dutch Renewables About-Face towards Nuclear

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Does Wind Energy Pay?: Because Denmark is a MODERATELY windy country, and many of its wind turbines are older, less efficient units, . . . its national average wind capacity factor (CF) was 0.242 for the 2005 -2009 period, not high enough for a private enterprise to make money with wind power, unless the subsidies are great.

The newer, offshore wind turbine facilities have CFs approaching 0.40. However, because the installed cost is well over $4,000/kW and the O&M (Operation & Maintenance) is about 3 times that of Danish onshore wind turbines, it is doubtful their wind energy is more competitive than onshore wind energy.

For a private enterprise to make money with wind power, low installed cost, say $2,000/kW, low O&M (1/3 of offshore) and a capacity factor of about 0.40, such as in many areas of the Great Plains states in the US, are required for the costs of moderately-subsidized, newer wind turbine facilities to be competitive with electricity of existing coal, gas and nuclear plants. Such Great Plains wind energy would cost less than the cost of electricity of NEW coal, gas and nuclear plants.

The low capacity factor, the additional grid management efforts to deal with wind energy, the transmission losses of sending wind energy to Norway’s and Sweden’s hydro plants, the wind energy output management, the wind energy integration fees paid to Norway and Sweden, and the above-market-rate FITs all make Danish wind energy a money-loosing operation; some of the losses are hidden in government accounts and the rest is recovered by adding very high taxes to Danish residential electric rates. As a result Danish household electricity cost of (energy+taxes+fees)/kWh are the highest in Europe. The untaxed Danish COMMERCIAL electric rates are at about 1/3 of the residential rate; a government manipulation to advantage its industrial companies?

The Danish wind elite will not find it easy to own up to this in public, so they advise other nations to “do as we do” and “go offshore”; Vestas, their national wind champion, will do more business as a result.

If the Danes cannot make wind pay at a national CF of 0.242, the Dutch (CF 0.186) and the Germans (CF 0.167) will not be able to make it pay either.

Growing Opposition to Wind Turbines: As the Danes became aware, largely because of the internet, that the poor economics of their heavily-subsidized wind energy is a major reason for Denmark’s high residential electric rates, opposition to the 400-ft tall onshore wind turbines increased so much over the past 6 years that Dong Energy, the giant state-owned utility, finally announced in August, 2010, that it would abandon plans for new onshore wind turbines and that any future wind turbine development would be offshore. This may have elicited a sigh of relief from the Danish people and a feeling they have some control of their government after all.

The reason for the slowness of Dong Energy is to protect Vestas, a national champion; with government subsidies it became the largest such company in the world (GE is second). . . .

Wind Energy and Job Creation: In 2009, the Institute for Energy Research commissioned the Danish think-tank CEPOS (Centre for Political Studies) to report on electricity exports from Denmark and the economic impact of the Danish wind industry. The report states that Danes pay the highest residential electric rates in the European Union (partly due to subsidized wind power), and that the cost of saving a metric ton of CO2 between 2001 and 2008 has averaged $124. The report estimates that 90% of the jobs were transferred from other technology industries to the wind industry, and that 10% of the wind industry jobs were newly created jobs, and states that as a result, Danish GDP is $270 million lower than it would have been without wind industry subsidies.

Subsidized job creation and industry building are economic downers not only in Denmark, but elsewhere as well, including Vermont, as shown by the White Paper Report by the Vermont Dept. of Public Service.

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Willem Post, Examples of Wind Power to Learn From

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Various government entities, eager to show their greenness regarding global warming, passed laws to subsidize renewable power, so-called “green power”, as if there is such a thing. Some governments even passed laws that declare hydropower as non-renewable, but, on reflection of its implications, reversed themselves and passed laws that declare hydropower IS renewable, as recently did Vermont’s legislature.

President Andrew Jackson, Democrat, Populist: “When government subsidizes, the well-connected benefit the most”. The renewables subsidies to the politically-well-connected often result in uneconomic wind power projects, some of which are described in this article.

Vendors, owners, financiers often claim “trade secrets”, whereas in reality they want to obfuscate wind power’s shortcomings, a too-generous subsidy deal, or other insider’s advantage. It would be much better for all involved, if there were public hearings and full disclosure regarding the economics of any project receiving government subsidies, to ensure the people’s funds receive the best return on investment.

EXAMPLE: UNIVERSITY of MAINE WIND POWER A DISMAL FAILURE?

The University of Maine, UM, decided to install a 600 kW wind turbine made by RRB Energy Ltd, an Indian company, at its Presque Isle Campus. Results from a 20-month wind resource assessment indicated the campus receives enough wind for a community wind project, not a commercial wind project.

Community wind power is defined as locally-owned, consisting of one or more utility-scale or a cluster of small turbines, totaling less than 10 MW, that are interconnected on the customer or utility side of the meter. The power is consumed in the community and any surplus is sent to the utilty which supplies power as needed.

The purpose was to generate power and to use the wind turbine as a teaching tool for the students. Because it is almost impossible to obtain operating data from the vendors, owners and financiers of wind facilities, UM, to its credit, decided to make available all of its wind turbine operating data.

Capital Cost and Power Production

Estimated capital cost $1.5 million
Actual capital cost $2 million; an overrun of 33%
The project was financed by UM cash reserves and a $50,000 cash subsidy from the Maine Public Utilities Commission.
Estimated useful service life about 20 years.

Predicted power production 1,000,000 kWh/yr
Predicted capacity factor = 1,000,000 kWh/yr)/(600 kW x 8,760 hr/yr) = 0.190

Actual power production after 1 year 609,250 kWh
Actual capacity factor for 1 year = 609,250 kWh/yr/(600 kW x 8,760 hr/yr) = 0.116; a shortfall of 39%
Value of power produced = 609,250 kWh/yr x $0.125/ kWh = $76,156/yr; if O&M and financing costs amortized over 20 years are subtracted, this value will likely be negative.

Actual power production after 1.5 years 920,105 kWh
Actual capacity factor for 1.5 years = (920,105 kWh/1.5 yrs)/(600 kW x 8,760 hr/yr) = 0.117

Operation and Maintenance

According to the European Wind Energy Association: “Operation and maintenance costs constitute a sizable share of the total annual costs of a wind turbine. For a new turbine, O&M costs may easily make up 20-25 percent of the total levelized cost over the lifetime of the turbine.”

Power Used by the Turbine (Parasitic Power)

Parasitic power is the power used by the wind turbine itself. During spring, summer and fall it is a small percentage of the wind turbine output. During the winter it may be as much as 10-20 % of the wind turbine output. Much of this power is needed whether the wind turbine is operating or not. At low wind speeds, the turbine power output may be less than the power used by the turbine; the shortfall is drawn from the grid.

Two little-wind days were selected; a summer day and a cooler winter day to show that in summer the parasitic power is less than in winter. In winter, the wind speed has to be well above 4.5 m/s, or 10.7 miles/hour, to offset the parasitic power and feed into the grid. Speeds less than that means drawing from the grid, speeds greater than that means feeding into the grid.

This will significantly reduce the net power produced during a winter. On cold winter days, even at relatively high wind speeds of 10.7 miles/hour, or greater, power is drawn from the grid, meaning the nacelle (on big turbines the size of a greyhound bus) and other components require significant quantities of electric power; it is cold several hundred feet above windy mountain ridges.

14 May, 2010, wind speed 2.9 m/s (6.9 miles/hour), net power output -0.3 kW.

20 Nov, 2010, wind speed 4.5 m/s (10.7 miles/hour), net power output -5.6 kW.

Below is a representative list of equipment and systems that require electric power; the list varies for each turbine manufacturer.

– rotor yaw mechanism to turn the rotor into the wind

– blade pitch mechanism to adjust the blade angle to the wind

– lights, controllers, communication, sensors, metering, data collection, etc.

– heating the blades during winter; this may require 10%-20% of the turbine’s power

– heating and dehumidifying the nacelle; this load will be less if the nacelle is well-insulated.

– oil heater, pump, cooler and filtering system of the gearbox

– hydraulic brake to lock the blades when the wind is too strong

– thyristors which graduate the connection and disconnection between turbine generator and grid

– magnetizing the stator; the induction generators used to actively power the magnetic coils. This helps keep the rotor speed constant, and as the wind starts blowing it helps start the rotor turning (see next item)

– using the generator as a motor to help the blades start to turn when the wind speed is low or, as many suspect, to create the illusion the facility is producing electricity when it is not, particularly during important site tours. It also spins the rotor shaft and blades to prevent warping when there is no wind.

Conclusions

The huge difference between predicted and actual capital cost and capacity factor would be disastrous for a commercial installation. Because this is for “teaching purposes” such a detail is apparently not that important. The capital cost and any operating costs in excess of power sales revenues will likely be recovered by additions to tuition charges.

UM should find less expensive ways to educate students in all areas, not just wind power. Cost per university student in the US is already well over 2 times that of Europe, a competitive disadvantage.

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Willem Post, Wind Power and Carbon Dioxide Emissions

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The New England Electric Grid, NEEG, managed by ISO New England, ISO-NE, has a generating capacity of about 34,020 MW, electrical energy supplied to the grid is about 130,000 GWh/yr. It includes over 350 central power plants and 8,000 miles of high-voltage transmission lines to serve about 6.5 million customers. The supply to 2010 NEEG is 55.4% from CO2-producing fossil fuels (44% gas, 11% coal, 0.4% oil), 29% from CO2-free nuclear, 6.2% from CO2-free hydro, 3.3% from interstate transfers, 3% from CO2-producing wood waste, 2.4% from CO2-producing solid waste and 0.7% from Other i.e., CO2-free wind, solar, etc. Almost all of this energy is STEADY and the T&D systems of the NEEG are designed accordingly.

Historically, electric grids have experienced varying electric demands during a day and varied the output of their generating plants to serve that demand and, at the same time, regulate frequency.

Cold, quick-starting, quick-ramping peaking plants, such as a mix of gas-fired OCGTs and CCGTs, are turned on and off each day to serve normal daily peak demands which occur once or twice per day. From a cold start, CCGTs take about an hour before there is enough steam pressure to operate the steam cycle. During this hour they run as OCGTs at about 30 to 35% efficiency, instead of the 55 to 59% efficiency as CCGTs.

Base-loaded coal and nuclear plants, which take about 6-12 hours from a cold start to rated output, are less suitable for variable output operation. Usually they operate near rated output for about a year for coal plants, for about 1.5 years for nuclear plants, after which they are shut down for 3-4 weeks for maintenance and refueling.

Base-loaded coal plants, designed for most economical, least polluting, steady operation near rated output, are often used to follow daily demand profiles and are sometimes used for the frequent, rapid balancing operations to accommodate wind energy; the coal plants used for such balancing operations need to be designed for ramp rates of 5-10 MW/min for a 500 MW plant.

Balancing operations of coal plants require more fuel per kWh and emit more pollutants, including SOX, NOX, CO2 and particulate per kWh, as shown by coal plants used for balancing in Colorado, Texas, etc. The main reason utilities use coal plants for balancing is because they lack sufficient capacity of hydro plants and gas-fired OCGT and CCGT plants to accommodate the mandated “must-take” wind energy.

Base-loaded nuclear plants, designed for most economical, steady operation near rated output, are very rarely used for balancing operations. They typically have capacity factors, CF, of 0.90 or greater.

Increased wind energy penetration will present additional challenges to grid managers, such as ISO-NE. Because wind energy is variable and intermittent, additional spinning, quick-ramping units, such as a mix of OCGTs and CCGTs, must be kept in 24/7/365 operation to supply and withdraw energy as required. The units must respond to changes of:

– demand of millions of users during a day.
– supply, such as from unscheduled plant outages.
– supply due to weather events, such as lightning, icing and winds knocking out power lines.
– supply from wind turbine facilities.

If these changes, especially those due to wind energy, are of high MW/min, the CCGTs may have to temporarily operate as OCGTs, because their heat recovery steam generators, HRSGs, would be damaged by the frequent, rapid, high amplitude balancing; HRSGs have lower ramp rates than OCGTs. This increased OCGT mode of operation increases fuel consumption, NOX and CO2 emissions per kWh.

An example of what ISO-NE may have to look forward to: California’s wind and solar generating capacity will increase significantly in the near future largely due to government subsidies and “must-take” mandates. The management of their variable power on the grid is anticipated to be a significant grid operating challenge as:

– predicting day-ahead wind and solar outputs remains elusive, even with weather prediction systems
– sufficient balancing capacity of flexible generating units, such as OCGTs and CCGts, is not available at present
– the grid structure lacks the required transmission flexibility.

The US Energy Information Administration projects levelized production costs (national averages, excluding subsidies) of NEW plants coming on line in 2016 as follows (2009$) :

Offshore wind $0.243/kWh, PV solar $0.211/kWh (significantly higher in marginal solar areas, such as New England), Onshore wind $0.096/kWh (significantly higher in marginal wind areas with greater capital and O&M costs, such as on ridge lines in New England), Conventional coal (base-loaded) $0.095/kWh, Advanced CCGT (base-loaded) $0.0631/kWh.

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Willem Post, Was Vermont’s Lowell Mountain Wind Turbine Facility a Good Idea?

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The Green Mountain Power-proposed 63 MW Lowell Mountain wind turbine facility with (21) 3 MW Danish, Vestas V-112 wind turbines, 373-ft (112 m) rotor diameter, 280-ft (84 m) hub height, total height (280 + 373/2) = 466.5 ft, stretched along about 3.5 miles of ridge lines, has nothing to do with community-scale wind, everything with industrial, utility-scale wind. The housings, 47 ft (14 m) long, on top of the 280-ft towers are the size of a Greyhound bus.

The GMP name for this facility is “Kingdom Community Wind”. GMP is using blatantly deceptive PR to soft-soap/deceive Vermonters.

GMP claims to be all about renewables, but it recently entered into an agreement with the Seabrook nuclear power plant to buy 60 MW of steady, 24/7/365, CO2-free nuclear energy at 4.66 cents/kWh, about half the cost of the Lowell wind energy which is variable and intermittent and only partially CO2-free, because it requires gas-fired, CO2-producing, quick-ramping balancing plant energy to make it useful for use on the grid. See below.

Gaz Metro of Quebec, Canada, owns GMP. It recently accquired Central Vermont Public Service Corporation. It now controls at least 70% of Vermont’s electrical energy market.

The wind energy production would be about 63 MW x 1 GW/1,000 MW x 8,760 hr/yr x capacity factor 0.32 = 176.6 GWh/yr, or 176.6/6,000 x 100% = 2.94% of Vermont’s annual consumption.

The capital cost of the wind turbine facility would be at least 63 MW x $2,500,000/MW = $157.5 million, excluding grid modifications.

The Lowell wind turbine facility facility would have a 20 – 25 year useful service life. However, gearboxes and blades sometimes fail within 5-10 years.

The CF of 0.32 and the $2,500,000/MW are the averages of recently-built, ridge line wind turbine facilities in Maine.

The average CF = 0.32 of the Maine wind turbine facilities was determined from public data provided by project developers. Actual CFs are a closely guarded business secret. It would be better if a project receives public subsidies, all operating data were required to be made public to ensure the public’s money is not wasted on non-viable projects, as often happens because of political inside dealing.

On ridge lines the terrain upstream of the rotor usually creates non-uniform wind speeds and turbulence which can significantly reduce the capacity factor of a wind turbine, especially if it has a very large diameter rotor. Also, the wind speed at the tip of one blade may be considerably greater than the wind speed at the tip of another creating additional stresses on the equipment. This is less the case on the flat plains of Kansas or offshore.

The reality is the Lowell Mountain wind turbine facility would be a capital intensive, highly-visual, noisy facility (100 dB(A) minimum, 106.5 dB(A) maximum) that is proposed to be built on environmentally-sensitive ridge lines. The wind turbines would be about 466.5 feet tall, equal to a 40-story building, with noise-making rotors.

People living within about 2 miles would be disturbed by an around-the-clock machinery noise and an irregular, throbbing, whoosh-type sounds, especially during nighttime. The noise will be similar to (21) Greyhound buses spread out on 3.5 miles of ridge lines on top of 280-ft towers simultaneously and continuously running their engines at a distance, 24/7/365 for 20 or more years; a total madness cooked up by GMP, aided and abetted by its minions in Montpelier. See “Increased Energy Efficiency” below.

Decision makers in Montpelier are far away from it all. They will likely not heed the complaints from those who live near the facility. They will certainly not heed the complaints from the fauna and flora currently inhabiting this pristine ridge line. Because of them, Vermonters are in danger of losing an international reputation of being preservers of their environment, in danger of losing a part of their soul.

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Willem Post, Wind Energy Is Expensive

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As the US moves to increased use of renewable energy to reduce CO2 emissions, it is important to recognize efficient technologies, such as gas-fired, advanced, 60%+ efficient, combined cycle gas turbines, CCGTs, that emit about one third the CO2 per kilowatt-hour of a coal plant.

The more cost effective renewables should have incentives towards deployment. The less cost effective renewables should have incentives towards further development.

An undesirable situation would arise if politically-inspired deployment would occur prior to a renewable being ready for deployment, as was, and still is, the case with ethanol-from-corn which costs not only billions of dollars in subsidies each year, but does not even reduce CO2 emissions; a most egregious policy disaster. . . .

Levelized Costs of Energy:  A partial list

The US Energy Information Administration projects levelized production costs (national averages, excluding subsidies) of NEW plants coming on line in 2016 as follows (2009$) :

Offshore wind $0.243/kWh; PV solar $0.211/kWh (significantly higher in marginal solar areas, such as New England); Onshore wind $0.096/kWh (significantly higher in marginal wind areas with greater capital and O&M costs, such as on ridge lines in New England; significantly lower in the Great Plains states); Conventional new coal (base-loaded) $0.095/kWh; Advanced 60%+ efficient CCGT (base-loaded) $0.0631/kWh.

Onshore Wind Energy Is Expensive

Kibby Mountain Wind Turbine Facility: TransCanada Power which owns the 132 MW Kibby Mountain Wind Facility in Maine has a 10-yr PPA with NStar, an electric utility, at a flat $0.105/kWh, plus the associated renewable energy certificates.

Power production is estimated at 132 MW x 8,760 hr/yr x CF 0.31 = 0.357 GWh/yr.

Capital cost is estimated at $320 million, or $2,424/kW.

The Kingdom “Community” Wind Project: The Green Mountain Power-proposed 63 MW Lowell Mountain wind turbine facility with (21) 3 MW Danish, Vestas V-112 wind turbines, 373-ft (112 m) rotor diameter, 280-ft (84 m) hub height, total height 466.5 ft, stretched along about 3.5 miles of ridge lines. The housings, 47 ft (14 m) long, on top of the 280-ft towers are the size of a greyhound bus.

With subsidies the levelized energy cost would be about $0.096/kWh, according to GMP

Power production is estimated at 63 MW x 1 GW/1,000 MW x 8,760 hr/yr x CF 0.32 = 176.6 GWh/yr

Capital cost is estimated at 63 MW x $2,500,000/MW = $157.5 million, excluding grid modifications.

Useful service life is estimated at 20 – 25 year. However, gearboxes and blades sometimes fail within 5-10 years. Standard manufacturer warrantees of blades and gear boxes are about 2 years.

Offshore Wind Energy Is Very Expensive

Cape Wind: Cape Wind Associates, LLC, plans to build and operate a wind facility on the Outer Continental Shelf offshore of Massachusetts. The wind facility would have a rated capacity of 468 MW consisting of 130 Siemens AG turbines each 3.6 MW, maximum blade height 440 feet, to be arranged in a grid pattern in 25 square miles of Nantucket Sound in federal waters off Cape Cod, Martha’s Vineyard, and Nantucket Island; the lease is for 46 square miles which includes a buffer zone.

The Massachusetts Department of Public Utilities approved a 15-yr power purchase agreement, PPA, between the utility National Grid and Cape Wind Associates, LLC. National Grid agreed to buy 50% of the wind facility’s power starting at $0.187/kWh in 2013 (base year), escalating at 3.5%/yr which means the 2028 price to the utility will be $0.313/kWh. The project is currently trying to sell the other 50% of its power so financing can proceed; so far no takers.

A household using 618 kWh/month will see an average wind power surcharge of about $1.50 on its monthly electric bill over the 15 year life of the contract; if the other 50% of power is sold on the same basis, it may add another $1.50 to that monthly bill.

Power production is estimated at 468 MW x 8,760 hr/yr x CF 0.39 = 1.6 GWh/yr.

The capital cost is estimated at $2.0 billion, or $4,274/kW. Federal subsidies would be 30% as a grant.

Block Island Offshore Wind Project: The 28.4 MW Block Island Offshore Wind Project has a 20-yr PPA starting at $0.235/kWh in 2007 (base year), escalating at 3.5%/yr which means the 2027 price to the utility will be $0.468/kWh. A State of Rhode Island suit is pending to overturn the contract; the aim is to negotiate to obtain a lower price.

Power production is estimated at 28.4 MW x 8,760 hr/yr x CF 0.39 = 0.097 GWh/yr.

Capital cost is estimated at $121 million, or $4,274/kW. Federal subsidies would be 30% as a grant.

Delaware Offshore Wind Project: The 200 MW Delaware Offshore Wind Project has a 25-year PPA starting at $0.0999/kWh in 2007 (base year), escalating at 2.5%/yr which means the 2032 price to the utility will be $0.185/kWh.

Power production is estimated at 200 MW x 8,760 hr/yr x CF 0.39 = 0.68 GWh/yr.

Capital cost is estimated at $855 million, or $4,274/kW. Federal subsidies would be 30% as a grant.

  1. Comment by Young (Hong Kong) on 08/18/2011 at 6:29 pm

    These reports full of scientific facts and data are what exactly I need to convince some government officials here. Thank you so much.

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