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Wind energy CO2 emissions reductions are overstated  

Credit:  Willem Post | theenergycollective.com 1 July 2012 ~~

Governments have passed laws that provide various subsidies to promote build-outs of wind and solar power systems to reduce CO2 emissions from fossil-fueled energy generators; CO2 is one of many contributors to global warming.

 

If CO2 is so important, why are real-time, 1/4-hr grid operations data not reported by grid operators to determine just how effective wind and solar energy is for reducing CO2 emissions and how effective one balancing generator is versus another? If Ireland and Texas can do it, so can Germany and every other nation with wind energy on their grids.

 

Instead, elaborate systems of emission factors are applied to fuel consumption data or energy production data for a week, or a month, or a year to calculate CO2 emission reductions, i.e., nothing is measured, monitored and reported on a real-time, 1/4-hr basis. 

 

Government statistics end up showing their CO2 emissions are declining month-to-month or year-to-year, i.e., our subsidizing policies are working, let’s charge ahead and tell everyone to do the same.

 

Various power systems engineers, with decades of experience designing and operating power plants and grids, some retired and finally free to speak their minds, have doubts whether the CO2 emissions reductions claimed by government officials and wind energy promoters are actually true.

 

The purpose of this article is to examine the issue of CO2 emissions reduction by wind energy in some detail. 

 

Dispatch Value, Variability and Intermittency of Wind Energy

 

Dispatch Value: Wind energy is significantly different from conventional gas, coal, nuclear and hydro energy; just ask any grid operator with significant wind energy on his grid. The latter are controllable and dispatchable on short notice,  whereas wind energy is a product of weather-dependent, variable wind speeds, i.e., its supply is unpredictable and uncontrollable. Therefore, it has zero-dispatch value to a grid operator. 

 

A grid operator needs to have available an adequate mix of generating capacity to serve peak demands for long-term planning purposes. The mix varies from grid to grid. Wind turbine systems have a capacity value in this mix. 

 

Example: For summer peak capacity planning, ERCOT counts 8.7 percent of wind turbine rated capacity as dependable capacity at peak demand, in accordance with ERCOT’s stakeholder-adopted methodology. According to ERCOT, the capacity value is a statistical concept created for generator planning purposes. It is based on multi-year averages of wind energy generation at key peak demand periods. 

http://www.ercot.com/news/press_releases/show/381

 

ERCOT’s capacity planning value of 8.7% does not mean the ENERGY of 8.7% of wind turbine rated capacity would be available at any specified “time-ahead” period. Because of the randomness of wind speeds, no one can accurately predict available wind energy at any future time. Hence, it’s not available “on-demand”, i.e., not dispatchable.

 

Variability: Because wind energy increases by the cube of the wind speed, any change in wind speed creates significant surges and ebbs of wind energy. If such energy were fed into the grid, it would create chaos. 

 

Thus, wind energy cannot stand on its own, has no value on its own, is completely useless, unless the grid has an adequate capacity of quick-ramping gas turbines and/or hydro plants that are required to inefficiently operate at part-load to be able to ramp up when wind energy ebbs and ramp down when it surges, which happens at least 100 times per day, to maintain grid frequency and voltage within required limits. 

 

If a grid does not have adequate capacity of such ramping plants, it either must acquire it, or connect to grids that do have it and do not need it for their own variable wind and solar energy.

 

Many grids, including Germany’s four grids, the Bonneville Power Authority, Texas, Colorado, etc., do not have a sufficient capacity of such quick-ramping generators. As wind energy on the grids increases, the grid operators are unable to balance the wind energy and need to  transfer it to neighboring grids for balancing, if possible, and/or implement curtailments.

 

Example: German wind power output, peaked at about 12,000 MW on July 24, 2011, four days later the peak was 315 MW; German wind turbines are located mostly in Northern Germany. 

 

Intermittency: Wind energy generation usually it is minimal during summer (it is almost non-existent in New England), moderate during spring and fall, and maximal during winter. Almost all the time it is maximal at night. 

 

In the Great Plains states, about 10-15 percent of the hours of a year wind energy is near zero (in Vermont 25 – 35 percent), because wind speeds are insufficient (less than 7.5 mph) to turn the rotors, or too great for safety. During these hours, wind turbines draw energy FROM the grid, and also during hours with slowly turning rotors when parasitic energy exceeds the generated energy. Rotors are often kept turning with grid energy to prevent the rotor shaft from “taking a set”.

 

Dispatch Value, Variability and Intermittency of Solar Energy

 

Dispatch Value: Solar energy is significantly different from conventional gas, coal, nuclear and hydro energy; just ask any grid operator with significant solar energy on his grid, as in Southern Germany. The latter are controllable and dispatchable on short notice,  whereas solar energy is a product of the rising and setting sun and it is weather-dependent; variable to complete cloudiness and fog; shade, snow and ice on panels, etc. Its supply is unpredictable and uncontrollable AND CANNOT BE TURNED OFF. Therefore, it has zero-dispatch value to a grid operator. 

 

A grid operator needs to have available an adequate mix of generating capacity to serve peak demands for long-term planning purposes. The mix varies from grid to grid. Solar systems could have a capacity value in this mix, but insufficient systems are in place to determine it, except possibly in Southern Germany.

 

Variability: As scattered clouds move over a large number of PV systems, as in Southern Germany and Southern California, they cause rapid, local decreases in output which adversely affects grid stability.

 

Example: One thousand  5 to 10 kW residential PV systems blanketed by a moving cloud would cause a wave-like, 5 MW output decrease that moves with the cloud. With multiple clouds, the grid voltage and frequency would become unstable over a large geographical area, as is the case in Southern Germany and Southern California. 

http://www.bp.com/liveassets/bp_internet/solar/bp_solar_global/STAGING/local_assets/downloads_pdfs/0_999/6DV_4_32.pdf

 

Unlike wind energy, solar energy CANNOT be turned off/curtailed, as in Southern Germany with about 1 million PV systems, when on sunny summer days solar output surges to about 12,000 MW to 14,000 MW and the energy in excess of demand has to be partially exported to France and the Czech Republic at fire sale prices, 5.5 euro cent/kWh or less, after having been subsidized at an average of about 50 euro cent/kWh. Any leftover/unwanted energy is grounded, i.e., wasted.


Example: Germany’s peak solar power is as little as 2% of rated capacity, or 340 MW (2% of end 2010 capacity), on cloudy days and when snow covers the panels.


Intermittency: Solar energy usually it is minimal in the morning, maximal at noon about 3-5 hours before the daily peak demand, minimal in the afternoon, minimal during foggy, overcast, snowy days, and zero at night. 

 

About 65-70 percent of the hours of a year solar energy is near zero.

 

Replacing Conventional Units

 

The above indicates there are many hours during a year when little or no wind and solar energy is generated. Therefore, almost all conventional generator units would still need to be kept in good operating condition, AND staffed 24/7/365, AND fueled to serve the daily demand when wind and solar energy is insufficient. 

 

Without economically-viable, utility-scale energy storage systems, wind turbines and solar systems cannot replace any conventional units. All the units that would be needed WITHOUT the existence of wind turbines and solar systems, would also be needed WITH the existence of those systems. 

 

Some of the conventional units would have less energy production with wind and solar energy on the grid, thereby adversely affecting their economics, which is further worsened due to increasingly inefficient start/stop, part-load and part-load-ramping operations.

 

BALANCING WIND ENERGY

 

Because wind energy is variable and intermittent, it requires hydro plants and/or quick-ramping, gas turbine plants and/or quick-ramping coal plants to ramp up when wind energy ebbs and ramp down when it surges which occurs at least 100 times per day, 24/7/365. 

 

A greater wind energy percent on the grid requires a greater capacity of generators to be in:

 

– starting/stopping mode (which is less efficient; more fuel and CO2/kWh)

 

– spinning mode (which produces no energy, but emits CO2, as an idling car)

 

– decreased part-load mode (which is less efficient; more fuel and CO2/kWh)

 

– increased part-load-ramping mode (which is less efficient; more fuel and CO2/kWh)

 

The net result is increased fuel consumption/kWh and CO2 emissions/kWh of the fossil units that significantly offsets the fuel and CO2 emissions that wind energy was meant to reduce, as proven by studies of the Irish, Texas and Colorado grid operations data. The studies are based on real-time, 1/4-hour and 1-hour grid operations data.

 

Nevertheless, government officials and wind energy promoters usually claim (without any measurements) one MWh of “clean” wind energy offsets one MWh of “dirty” fossil fuel energy and its associated CO2, i.e., a 1 : 1 ratio. This means 10% wind energy on the grid should reduce the grid CO2 emission intensity by 10%. 

 

However, a recent NREL study of the coal-dominated State of Illinois grid shows the 1 : 1 ratio is not valid. The study shares the usual flaws of other such NREL studies by being based on estimates, probabilities, algorithms, assumptions, grid operations modeling, weather and wind speed forecasts, etc., but, to its credit, it included CO2 emissions estimates of the increased starting/stopping mode and increased spinning mode of generators due to wind energy on the grid.

 

Argonne National Laboratory, Grid realities cancel out some of wind power’s carbon savings, May 29, 2012; http://www.anl.gov/articles/grid-realities-cancel-out-some-wind-power-s-carbon-savings

 

In general, for grids with low ANNUAL wind energy percent, such as the 0.6% on the New England grid, the ratio is about 1 : 0.95 during greater wind speed periods. The ratio will decrease as more wind energy is added to the grid. 

 

A study of the Irish grid, dominated by gas turbine energy, shows the ratio is about 1 : 0.7 or less, with about 12.7% annual wind energy. See below.

 

BACKGROUND INFORMATION ON THE IRISH GRID

 

The Irish grid will be a major focus of this article because EirGrid, the grid operator, makes available the most complete real-time, 1/4-hour grid operations data for study.

 

Ireland’s Energy Generation: Ireland’s total electricity production was about 26,000 GWh in 2010. Gas-fired OCGTs and CCGTs provided about 65.5%, coal 13.2%, peat 8.2%, wind 9.8%, hydro 2.5% of which 1.7%, or 442 GWh, was impounded/run-of-river hydro. Ireland imports 100% of its coal, about 90% of its gas and produces 100% of its peat.

 

Wind Energy: In Ireland, good wind energy months are April, May, June, November and February.  On the west coast of Ireland, wind energy is greatest during summer daytimes, because of increased wind speeds as the lands warms up. The west coast wind energy coincides with greater daytime demands which is fortuitous. However, much of the energy needs to be transmitted to the east coast (line and transformer losses), as few people live on the west coast. 

 

This video, based on EirGrid data, shows wind output, MW, and total system output, MW, versus time, from 2001-2011. As Irish wind ouput increased from year-to -year, it became an increasingly larger fraction of the total system output, especially during very windy nighttime periods when demand is minimal.

//www.youtube.com/watch?v=TYtsUkgMhwU

 

Coal/Peat: The below website shows coal/peat plants are base-loaded, i.e., not used for balancing wind energy, i.e., their CO2 emission intensities are essentially constant. 

http://ee.ucd.ie/erc/member/2005transdenny.pdf

 

Hydro: Ireland has many small hydro plants and a few larger plants, such as the Ardnacrusha power plant, built 1929, capacity 85 MW, output 332 GWh/yr, Cathaleens Falls 45 MW, Poulaphuca 30 MW and Inniscarra 19 MW. The below website shows hydro plant outputs follow daily demand, i.e., not used for balancing wind energy.

http://www.dconnolly.net/files/Modeling%20the%20Irish%20Energy-System%20-%20Data%20Required%20for%20the%20EnergyPLAN%20Tool.pdf

 

The almost 40-year old, 292 MW Turlough Hill pumped-storage facility pumps to add to its upper reservoir during low nighttime demand and produces energy during peak daytime demand. Its net effect is to “flatten” the daily demand profile. It is not used for balancing wind energy. Currently, it operates at about 50% of capacity, because of ongoing modifications.  

 

Combined-Heat-Power: Ireland has about 195 units totaling about 282 MW of operating combined-heat-power, CHP, plants of which a few larger units totaling 248 MW are dedicated to industrial processes, such as food, manufacturing and pharmaceutical. The output of these units is independent of the weather.

 

CHP energy generation was 6.3% of Ireland’s total energy generation in 2008 (latest data). 

Only 11 CHP units (mostly associated with industrial processes) exported 1,013 GWh to the grid in 2008, or 1,013/260 = 3.9% of total production. Eirgrid includes the exported energy and associated CO2 emissions of these units in its 1/4-hour data sets.

 

CHP heat generation was 4% of Ireland’s total heat generation in 2008 (latest data).

 

The above indicates CHP operations have no material impact on the 1/4-hour CO2/kWh posted by EirGrid.

http://www.seai.ie/Publications/Statistics_Publications/EPSSU_Publications/CHP%20in%20Ireland%202010%20Report.pdf

 

OCGTs/CCGTs: A part of the OCGT/CCGT capacity serves base-load, follows daily demand, provides peaking power and performs voltage and frequency regulation. It also performs wind energy balancing, i.e., ramps down with smaller wind energy surges and ramps up with small wind energy ebbs.

 

Because larger wind energy surges and ebbs are unpredictable, additional OCGT/CCGT capacity needs to be in spinning and part-load-ramping mode for balancing wind energy; the greater the wind energy, the greater the additional  spinning and balancing capacity. 

 

Because of much degraded heat rates, Btu/kWh, and their combustion process becoming unstable, gas turbines are rarely operated below 40% of their rated output which limits their ramping range from 40 to 100 percent of rated output.

http://theenergycollective.com/willem-post/57905/wind-power-and-co2-emissio

 

Fossil Units Less Efficient With Wind Energy: In the gas-energy-dominated Irish system, wind energy displaces mostly CCGT energy which, at zero wind energy on the grid, has CO2 emissions of 117 lb of CO2/(million Btu x 1 kWh/7,000 Btu) = 0.819 lb/kWh x 1/2.205 = 371 g/kWh, at an average turbine efficiency of (3,413 Btu/kWh)/(heat rate of 7,000 Btu/kWh) = 48.85%.; Ireland has mostly newer model CCGTs. 

 

The addition of wind energy to the Irish grid causes less efficient operation of the fossil units; i.e., extra Btu/kWh and extra CO2 emissions/kWh which significantly offset what wind energy was meant to reduce.

 

How EirGrid Calculates CO2 Emissions/kWh: The following is a direct quote from the EirGrid website:

 

“EirGrid, with the support of the Sustainable Energy Authority of Ireland, has developed together the following methodology for calculating CO2 Emissions.

 

The rate of carbon emissions is calculated in real time by using the generators MW output, the individual heat rate curves for each power station and the calorific values for each type of fuel used.

 

The heat rate curves are used to determine the efficiency at which a generator burns fuel at any given time.

 

The fuel calorific values are then used to calculate the rate of carbon emissions for the fuel being burned by the generator“

 

Grid operators know the heat rate curves of the plants on their grids which were obtained by testing. They need to know this for economic dispatch.

 

Eirgrid takes the percent of rated output each plant is operated at and multiplies it by the heat rate for that output percentage (from the above mentioned heat rate curve) to calculate the fuel consumption/kWh and CO2 emissions/kWh every 1/4 hour. It posts the grid CO2 intensity (CO2 emissions of all plants/total kWh produced by all plants) as gram CO2/kWh on its website every 1/4 hour.

 

STUDY OF WIND ENERGY ON THE IRISH GRID

 

The Irish grid was selected to determine the CO2 emission reductions due to wind energy on the grid. 

 

Eirgrid, the grid operator, is one of the few operators that publishes the following real-time, 1/4-hr grid operations data which are, for study purposes, superior to the 1-hr data published by Texas and Colorado.

 

– grid CO2 emission intensity, gram/kWh

– wind energy produced, GWh

– total energy produced, GWh 

 

Dr. Fred Udo, a graduate of the Technical University of Delft, the MIT of the Netherlands, spent a good part of his career at CERN, Switzerland, performing analyses of engineering and scientific data. He is retired, has no financial interest in RE. He performed several studies of the real-time, 1/4-hr data published by EirGrid.

 

http://www.clepair.net/IerlandUdo.html 

http://www.clepair.net/Udo-okt-e.html

http://www.clepair.net/Udo-curtail201205.html

 

Analysis of the November 2010 to August 2011 EirGrid grid operations data shows at an average wind energy penetration of 12.6%, the average efficiency of reducing CO2 emissions is about 70%, i.e., a ratio 1 : 0.7, for that 10-month period.

 

Wind energy: 12.6%

System, with wind energy: CO2 =  451.3 g/kWh

System, without wind energy: CO2 = 495 g/kWh

Fossil plants only: CO2 = 518.1 g/kWh

Reduction: (495 – 451.3)/495 = 8.9%

Efficiency: 8.9/12.6 = 70.6%

 

See Table 2 in http://www.clepair.net/IerlandUdo.html

 

How EirGrid Understates CO2 Emissions/kWh: The 1/4-hour reported CO2 emissions/kWh are understated, as Eirgrid does not account for the extra fuel/kWh and CO2 emissions/kWh due to:

 

– Increased spinning plant operations; fuel and self-use energy is consumed, no output to the grid 

– Increased start/stop operations; fuel and self-use energy is consumed, minimal output to the grid 

– Increased part-load-ramping operations with wind energy than without wind energy.

– less than optimum economic scheduling of generating units with wind energy than without wind energy.

– increased line losses to gather the distributed wind energy from wind turbines.

– parasitic/self-use energy drawn from the grid by the wind turbines during low/no-wind periods.

 

If EirGrid had accounted for all of the above items, wind energy’s CO2 reduction effectiveness would have been significantly less than the 70% based the reported EirGrid data.

 

Note: In my discussions with Mr. O’Sullivan, energy systems analyst of Eirgrid, he confirmed: 

 

– Eirgrid’s reported CO2 emissions accounts for part-load operations, but not the ramping operations and the other above-listed factors.

 

– CO2 emissions reduction is secondary, as there are other reasons for building out wind energy, such as the Brussels’ mandated renewable energy percentages that provide Ireland with subsidies for wind turbine facilities.

 

– Ireland wants to reduce its fuel imports and increase its wind energy exports to Britain. 

 

The analysis of the EirGrid data also found:

 

– the greater the wind energy percent on the grid, the lower the ratio, i.e., adding still more wind energy becomes less and less effective for CO2 emissions reduction.

 

– at very high wind energy percent on the grid, the ratio will ultimately go to zero and then become negative, i.e., adding still more wind energy to the grid will actually INCREASE CO2 emissions.

See Figure 1 in http://www.clepair.net/Udo-okt-e.html

 

The decreasing CO2 emission reduction effectiveness was verified by preparing a scatter diagram of the EirGrid data. The fit lines of the scatter diagrams of CO2 emission intensity, g/kWh, versus wind energy, %, show increasing CO2 emissions/kWh of the fossil units as wind energy percent increases. Where the fit line intersects the Y-axis, i.e., no wind energy, is their lowest CO2 emissions/kWh.

See Figure 1 of http://www.clepair.net/Udo-okt-e.html 


Opinions of Experienced Power Systems Engineers: The above findings appears entirely reasonable to power system engineers who know the more their power generators are operated in part-load and part-load-ramping mode, the less efficient they become and the less efficient the whole grid becomes.

 

Here is the testimonial of a UK power systems engineer with decades of experience in the utility industry. He is retired, i.e., finally free to speak up, and claims CO2 emission reduction due to wind energy is minimal.

http://fifewindfarms.org.uk/wind-turbines-do-they-increase-carbon-emissions/

 

Here are two articles by William Palmer, a retired power systems engineer of the Ontario Power System.

 

http://www.masterresource.org/2012/02/ontario-windpower-case-study-i/

http://www.masterresource.org/2012/03/ontario-windpower-case-study-ii/

 

Just as a car, if operated at 20 mph, then accelerated to 50 mph and back down again a few hundred times during a 24-hour trip would use more gas and pollute more than operated at a steady speed, so would the balancing CCGTs and OCGTs.

 

However, gas turbines operating in part-load-ramping mode have even greater degradations of heat rates, Btu/kWh, than gasoline and diesel engines. The extra fuel consumed and extra CO2 emitted by the gas turbines are so much that they significantly offset what wind energy was meant to reduce. 

 

Grids Using Primarily Hydro Plants for Balancing: Balancing wind energy with hydro plants incurs the least cost/kWh and CO2 emissions/kWh. The outputs of hydro plants are controlled by varying the water flow to the turbines. The turbines need to operate in part-load-ramping mode for balancing wind energy which is less efficient, i.e., more waterflow/kWh, and incurs more wear and tear than if they were operated to follow daily demands without wind energy on the grid.  

 

Example: Danish wind energy in excess of Danish demand is fed into the Nordpool grid and absorbed and balanced by the hydro plants of Norway and Sweden thereby maintaining their reservoirs at higher levels than they would have been. 

 

Norway and Sweden buy the Danish energy from the Nordpool grid mostly at very low nighttime rates. Norway and Sweden use the saved water in their reservoirs to generate energy to serve the Nordpool grid daytime demands when rates are higher. 

 

Denmark “exporting” subsidized energy, is, in fact, a flow of foreign aid from Danish to other Nordic consumers of up to one billion DKK during a “big export year”. To make matters worse, Denmark is proudly aiming to have 50% of its energy production from on- and offshore wind turbines, almost all of which will need to be “exported”. 

 

A good deal for Norway and Sweden, a bad deal for Denmark. The extra costs are rolled into Danish household electric rates (31.5 euro cent/kWh in 2011, highest in Europe), while industrial rates are kept low for international competitive reasons, as are Germany’s household (27 euro cent/kWh in 2011, second highest) and industrial rates. 

 

All this is justified, because the nearly-bankrupt Vestas, a national “champion” whose stock has declined about 95%, is creating wind turbine jobs in Denmark.

 

Grids Using Primarily Coal Plants for Balancing: Older coal plants were designed to be base-loaded, not designed to have the high ramping rates required for wind energy balancing. Newer coal plants, if designed for higher ramping rates, are more suitable for wind energy balancing. Whereas the operating range of gas turbines is about 40 – 100 % of rated output, of coal plants it is about 50 -100 % of rated output.

 

The operation of coal plants in part-load-ramping mode for balancing wind energy, especially during high-wind-speed periods, may destabilize combustion control systems causing extra fuel consumption, CO2 emissions and NOx emissions/kWh, and destabilize air quality control systems causing extra particulate, NOx and SOx emissions/kWh.

 

The extra fuel consumption and CO2 emissions causes the average efficiency of reducing CO2 emissions to become about 70%, i.e., a ratio 1 : 0.7, as shown by the Texas and Colorado grids when coal plants of various vintages were used for wind energy balancing during high wind speed periods, because of insufficient available capacity of quick-ramping gas turbines.

 

http://docs.wind-watch.org/BENTEK-How-Less-Became-More.pdf

http://theenergycollective.com/willem-post/64492/wind-energy-reduces-co2-emissions-few-percent

 

Grids dominated by coal plants of various vintages and an ANNUAL wind energy percentage of 5% or greater, have significant operational challenges regarding frequency and voltage regulation and balancing of wind energy, especially during high windspeed periods when INSTANTANEOUS wind energy on the grid may be 20% or greater during periods of low demand, such as at night when wind speeds usually are greatest.

 

In a system dominated by coal, wind energy primarily displaces gas turbine energy and coal energy which has CO2 emissions of at about 2.15 lb/kWh x 1/2.205 = 975 g/kWh.

 

Note: Modern subcritical boilers, supercritical boilers, ultra-supercritical boilers are more efficient and have CO2 emissions of 838 g/kWh, 800 g/kWh, 770 g/kWh, respectively.

 

Any CO2 emissions reduction in such a coal-dominated grid would depend on the weather-dependent wind energy %, the fuel types and consumption, and the changes of: 

 

– start/stop operations, and the type of units 

– spinning plant operations, and the type of units 

– part-load operations, and the type of units

– part-load-ramping operations, and the type of units

– scheduling of units to integrate wind energy; likely less economical than without wind energy.

 

INCREASED ENERGY EFFICIENCY

 

Ratios of 1 : 0.95 are likely to occur due to energy efficiency measures. EE is the low-hanging fruit, has not scratched the surface, is preferred to wind energy, because:

 

EE is invisible, AND it does not make noise, AND it does not destroy pristine ridge lines/upset mountain water runoffs, AND it would reduce CO2, NOx, SOx and particulates more effectively than wind energy, AND it would not require the transmission network build-outs for wind energy, AND it would slow electric rate increases, AND it would slow fuel cost increases, AND it would slow depletion of fuel resources, AND it would create 3 times the domestic jobs and reduce 3-5 times the Btus and CO2 per invested dollar than wind energy, AND all the technologies are fully developed, AND it would end the wasteful subsidizing of expensive wind energy tax-shelters mostly benefitting the top 1% at the expense of the other 99%, AND it would be more democratic/equitable, AND it would do all this without the public resistance and controversies associated with wind energy.

 

OTHER ASPECTS OF WIND ENERGY

 

Ireland’s Wind Energy Export Plan

 

Ireland’s long-term plan is to reduce its dependence on imported gas for producing energy. As wind speeds in Ireland are among the best in Europe, it has built about 2,000 MW (end of June 2012) of wind turbines during the past 10 years to supply energy to the Irish grid; gas turbine plants are used to balance the wind energy. Very little of this energy is exported to the UK.

 

This is about to change, because Greenwire, a wind turbine project investor/developer, has made a proposal to locate 3,000 MW of wind turbines, say 1,000 @ 3 MW/each, arranged in ten 300 MW clusters of 100 wind turbines each, in the Irish Midlands by the end of 2018. All of the wind energy would be exported to the UK. 

http://theenergycollective.com/willem-post/98061/irelands-wind-energy-export-plan

 

Wind Energy Integration Fees

 

For a proper evaluation of wind energy cost, the total would have to include not only the LCOE of the wind turbines, but also all or part of the LCOEs of:

 

– Increased regulating plant operation for grid stability; extra fuel and CO2

– Increased spinning plant operation; extra fuel and CO2

– Increased start/stop operations; extra fuel and CO2

– Increased part-load operation; less efficient, extra fuel and CO2 

– Increased part-load-ramping operation; less efficient, extra fuel and CO2

– Increased wear and tear of equipment of generating units  

– staffing, fueling and operation of most of the existing generating units 

– less than optimum economical scheduling of plants due to wind energy on the grid

– less economical operation of existing plants due to increasing wind energy production

– expanded transmission and distribution systems

– increased grid management systems, staffing and operation 

– increased weather and wind speed forecasting systems, staffing and operation

 

Rarely are any of these costs identified, quantified and charged to wind turbine owners as wind energy integration fees, i.e., they are getting a free ride.  

 

The above costs are not yet separately identified and quantified by grid operators, generator owners and utilities, because heretofore they have been relatively minor. But as wind energy percent increases, they will be come increasingly greater expenses, as experienced by other grids with greater than about 3% annual wind energy.

 

Grid operators typically add their extra costs to the invoices sent to utilities and generator owners that supply the grid.

 

Utilities typically add their extra costs to their other costs to justify rate increases. How generator owners will be compensated for the adverse impact of wind energy on the economics of their generators remains an open question.

 

Legislators, who wear the “RE” label to get votes, and utilities, dependent on rate increases from legislatures, are loathe to investigate, as it would be considered adverse to RE. They usually work together to make these costs “disappear”, i.e., socializing them, by rolling any RE costs mostly into household rate schedules; Denmark, a role model, has done it for decades and Danish households “enjoy” the highest electric rates in Europe; Germany’s households “enjoy” the second highest rates.

 

The lowest-cost wind energy balancing is with hydro energy. Higher cost wind energy balancing is with gas-fired, quick-ramping gas turbines. It is highly unlikely all of the above costs are included in the wind energy integration fees.

 

Hydro-Quebec, using hydro plants, charges wind turbine owners $5/MWh. 

The Bonneville Power Authority, BPA, using hydro and gas turbine plants, charges $5.7/MWh.

The Netherlands, using gas turbine plants, charges $10/MWh. 

 

http://www.lawofrenewableenergy.com/2009/07/articles/bpa-issues-decision-on-wind-integration-charge-in-2010-rate-case/ 

http://www.hydroworld.com/index/display/article-display/354308/articles/hydro-review/volume-26/issue-4/departments/the-leading-edge.html

 

Parasitic Energy Demand of Wind Turbines

 

Wind turbines need energy for their own operation 24/7/365. The parasitic energy demand can be 10%-15% of rated output on cold winter days, whether operating or not. 

 

Example: The average Danish Vestas-V82 wind turbine produces about 1,650 kW x 0.228 (2007 CF) = 376 kW. The AVERAGE power draw from the grid to keep itself running is about 50 kW and at times up to 80 kW. Thus, a V82 operating in Denmark has an annual average brochure output of about 376 kW +50 kW = 426 kW, but an actual output of about 376 kW, about 13%  less than advertised in Vendor brochures. No wonder Vendors keep quiet about parasitic energy; at 426 kW, the CF would have been 426/1,650 = 0.258.

 

http://theenergycollective.com/willem-post/53258/examples-wind-power-learn

http://windfarmrealities.org/?p=1594

 

Example: The Enercon-82, capacity 2 MW, hub height 138 m (460 ft), rotor diameter 82 m (273 ft), for a total height of about 600 ft. The unit requires a substantial foundation. The installed cost is about $2,600/kW. 

 

The units have a fan with an electric heater and duct system in each blade to circulate warm air through the uninsulated, hollow blade to keep it warm in winter to prevent icing that impairs blade aerodynamics, as on an airplane wing. Total power draw of the blade heating system is about 60 kW, plus about 50 kW for other parasitic loads. 

http://www.slideshare.net/WinterwindConference/further-development-of-enercons-deicing-system-christoffer-jonsson-enercon 

 

Comparison of Wind Energy with Advanced CCGT Energy 

 

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 greater in marginal solar energy areas, such as New England) 

 

Onshore wind $0.096/kWh (significantly greater in marginal wind energy areas with greater capital and O&M costs, such as on ridge lines in New England; less in the Great Plains states) 

 

Conventional new coal (base-loaded) $0.095/kWh 

 

Advanced 60%+ efficient CCGT (base-loaded) $0.0631/kWh.  

http://www.energytransition.msu.edu/documents/ipu_eia_electricity_generation_estimates_2011.pdf

 

Without subsidies, the US average LCOE of onshore wind energy is about 0.096/0.0631 x 100% = 52% greater than advanced CCGT. 

 

Without subsidies, the US average LCOE of offshore wind energy is about 0.243/0.0631 x 100% = 385% greater than advanced CCGT, because of much greater (owning + O&M) costs. 

 

The below table summarizes capital costs, O&M, capacity factors and unsubsidized LCOEs for recently-built/proposed IWT systems in different regions. The Great Plains, GP, has the least cost O&M; it is set at 1; New England, ridgeline O&M is about 2x GP; New England, offshore O&M is 3-4 times GP.

                                

                                                    Cap Cost            O&M       CF       LCOE       LCOE

                                                        $/kW                                      $/kW      $/kW

                                                                                                      WO/sub  W/sub

 

New England grid price                                                                                   0.055                 

Great Plains                                     1,800                1         0.40     0.090     0.700

New England, ridgeline               2,500 – 2,800          2         0.32     0.150     0.100

New England, offshore                     4,200                3-4      0.40     0.243     0.170

 

Note: The above wind energy LCOEs do not include all of the LCOEs listed under “Wind Energy integration Fees” in this article. 

 

Without subsidies, the LCOE, NE ridgelines, would be at least 0.15/0.0631 x 100% = 238% greater than advanced CCGT.

 

With subsidies, the LCOE, NE ridgelines, would be at least (0.092/0.0631) x 100% = 46% greater than advanced CCGT.

 

If the production tax credit of $0.022/kWh expired, the LCOE would be about {(0.092+0.022)/0.0631} x 100% = 81% greater than advanced CCGT. 

http://vtdigger.org/2011/07/10/lowell-mountain/

 

Reference: 

– Maine wind turbine facilities have an average installed cost of about $2,500/kW and an average capacity factor of 0.32. 

– The Granite Reliable Power Windpark, Coos County, NH, has 33 Vestas units @ 3 MW each, capital cost $2,778/kW. 

 

http://theenergycollective.com/willem-post/47519/base-power-alternatives-replace-base-loaded-coal-plants

http://www.coalitionforenergysolutions.org/maine_wind_farms.pdf  

http://www.energytransition.msu.edu/documents/ipu_eia_electricity_generation_estimates_2011.pdf

http://theenergycollective.com/willem-post/57905/wind-power-and-co2-emissions

http://theenergycollective.com/willem-post/59747/ge-flexefficiency-50-ccgt-facilities-and-wind-turbine-facilities

http://theenergycollective.com/willem-post/61309/lowell-mountain-wind-turbine-facility-vermont 

 

A Lack of Real-time, 1/4-hr Data Hampers Proper Inquiry

 

The above study of the Irish grid could only be performed, because EirGrid publishes real-time, 1/4- hour grid operations data. Almost all grid operators HAVE those data, as they need them to properly operate their grids and for economic dispatch, but do not publish them because:

 

– they are not required to, or they do not want to.

– wind turbine owners claim their data are proprietary.

– wind turbine vendors and owners have lobbied legislatures to maintain the “do-not-tell” status quo. 

 

Note: RE departments of governments and other organizations are filled with people who would not have their wind energy jobs and federal and state wind energy subsidies would be at risk, if grid operators were required by law to publish real-time, 1/4-hr grid operations data,  

 

Because the real-time, 1/4-hr grid operations data is generally not made public, it became possible for government leaders and wind energy promoters to make unrealistic CO2 emissions reduction claims, such as the 1 : 1 ratio, using studies based on estimates, probabilities, algorithms, assumptions, grid operations modeling, weather and wind speed forecasts, etc., and thereby maintain a spell of deception and delusion regarding the claimed CO2 emission reduction benefits of wind energy.

 

Whereas such studies are costly, complex, look impressive, and create the appearance of serious inquiry to the lay public (many of those studies are performed and/or financed by wind energy promoters, such as the AWEA, US DOE, NRELs, et al), simulation studies usually introduce subjective elements (such as minor tweaking of the values of the study parameters or omitting certain aspects) that skew the results and conclusions more favorable to wind energy. 

 

The performers of such studies usually claim they have to do them the simulation way, because real-time, 1/4-hr data is not available. However, they are well aware, as are most energy systems analysts managing electric grids, real-time, 1/4-hour grid operations data, as published by EirGrid, are superior to any simulations for performing wind energy studies, an inconvenient truth for wind energy promoters. 

 

As a result of the similar methodologies, these simulation studies tend to produce similar outcomes in favor of wind energy, which reinforces the orthodoxy of wind energy promoters, such as the AWEA, US DOE, NRELs, et al. Any study at variance with their orthodoxy, such as of the Irish grid, are readily denounced/debunked as biased, a special case, cherry-picking, using statistical trickery, etc.

 

http://theenergycollective.com/willem-post/64492/wind-energy-reduces-co2-emissions-few-percent

http://www.clepair.net/IerlandUdo.html 

http://docs.wind-watch.org/BENTEK-How-Less-Became-More.pdf

http://www.clepair.net/windSchiphol.html 

http://www.clepair.net/Udo-okt-e.html

http://www.clepair.net/Udo-curtail201205.html

 

The above shows:

 

– the lay public has been led to believe by government leaders and wind energy promoters that wind energy is “fighting climate change and global warming”. Building out the wind energy “solution” would be much less attractive regarding CO2 emissions reduction and more costly/kWh than meets the eye.

 

– too many renewable energy certificates, RECs, are being granted to wind energy producers than is warranted based on their actual CO2 emissions reduction. 

http://theenergycollective.com/willem-post/83704/reduce-co2-and-slow-global-warming

 

WIND ENERGY NOT A RATIONAL SOLUTION

 

A national wind energy build-out would: 

 

– result in a littering of the US landscape with several hundred thousand, 450-ft to 550-ft tall, noise-making, health-damaging, industrial wind turbines everywhere there is wind. See note.

 

– require connecting them all with highly-visible, transmission systems.

 

– require integrating their variable, intermittent, zero-dispatch-value energy into the grid using less-efficiently operated hydro plants in some places and inefficiently-operated, CO2-emitting, gas turbine plants almost everywhere else.

 

– require rolling a part of the above mentioned LCOEs/kWh into rate schedules; households and small businesses would bear the brunt, because bigger businesses would be largely exempted for international competitive reasons, as is the case in Denmark and Germany.

 

– the CURRENT US energy production is about 4,000 TWh/yr, would be 6,578 TWh/yr in 2062, at a 1%/yr growthrate. Wind energy production: 300,000 IWTs x 3 MW each x 8,760 hr/yr x US capacity factor 0.25 = 1,971 TWh/yr, 30% of 2062 production. 

 

Note: The CF =  0.25 is an average of many US sites and accounts for transmission and distribution losses, i.e., gather wind energy from remote offshore/onshore windy regions and deliver it to population centers.

 

– the capital cost (2012$) would be trillions of dollars (wind turbines, gas turbines, transmission). 

 

Wind turbines: 200,000 x 3 MW x $2,000,000/MW (onshore) + 100,000 x 3 MW x $4,200,000/MW (offshore) = $2.46 trillion 

Gas turbines for balancing: 400,000 MW x $1,500,000/MW = $0.6 trillion 

Transmission: $0.3 trillion

Total = $3.36 trillion.  

 

As the build-out would take at least 50 years and the wind turbine useful service life is about 20 years, wind turbines built in the first 20 years would need to be replaced during the next 20 years, etc. This is in addition to further build-out to achieve a capacity of 900,000 MW by 2050. Additional capital cost for year 0 -20  replacements, plus year 20 – 40, plus year 40 – 50 = 20 yr/50 yr x 900,000 MW/2 x $1,500/MW x 2.5 = $450 billion, for a total of $3.38 + $0.45 = $3.83  trillion.

 

Note: For about 50% of that capital the US could build 500,000 MW of nuclear plants that would last about 60 years to produce 500,000 MW x 8,760 hr/yr x CF 0.90 = 3,942 TWh/yr, 60% of 2062 production, of relatively low-cost, CO2-free, steady, 24/7/365 energy and that would use most of the existing grid system, i.e., twice the energy production for half the capital cost AND none of the cost and ever-present risk of grid stability deterioration due to variable, intermittent wind energy being added to the grid.

 

Note: Before variable, intermittent wind and solar energy, Germany had the most reliable and stable power system in the world that was ideally suited for its various heavy industries. Now, with just 7% annual wind energy and 3% annual solar energy, the German power system needs to be rescued hundreds of times a year to prevent power outages. What would happen with 20% annual wind energy and 6% annual solar energy? 

 

Example: According to Tennet, one of the four system operators in Germany, the number of network interventions to stabilize the power system rose to several hundred in 2011. Just a few years ago, grid operators only had to intervene around 15 times a year to ensure a reliable and stable power supply. The grids of Texas, Colorado, etc., have similar experiences.

http://www.europeanenergyreview.eu/site/pagina.php?id_mailing=296&toegang=d296c101daa88a51f6ca8cfc1ac79b50&id=3799

 

– most of existing energy plants would still need to be staffed 24/7/365, fueled and kept in proper operating condition to provide energy when wind and solar energy are insufficient. With less production, the economics of these plants would be adversely affected; a politically untenable situation requiring primarily household electric rates be raised to compensate owners. 

 

– Assuming conventional coal plants would be phased out during those 50 years, the other 70% of energy would primarily be from natural gas, nuclear, hydro, coal gas, and PV solar. Energy from coal gas, wind, and PV solar likely would not be competitive with natural gas, unless subsidized or given other preferred treatment.

 

http://theenergycollective.com/willem-post/84293/wind-turbine-noise-and-air-pressure-pulses

http://theenergycollective.com/willem-post/89476/wind-energy-co2-emissions-are-overstated

http://theenergycollective.com/willem-post/83704/reduce-co2-and-slow-glo…

http://theenergycollective.com/willem-post/47519/base-power-alternatives-replace-base-loaded-coal-plants

 

Additional References Showing a Lack of CO2 Emissions Reductions: 

 

Bentek Energy LLC, How Less Became More: Wind, Power and Unintended Consequences in the Colorado Energy Market, http://www.bentekenergy.com/WindCoalandGasStudy.aspx

 

Institute for Energy Research, June 2010: http://www.instituteforenergyresearch.org/2010/06/23/wind-integration-does-it-reduce-pollution-and-greenhouse-gas-emissions/

 

Argonne National Laboratory, System-Wide Emissions Implications of Increased Wind Power Penetration, March 5, 2012; http://pubs.acs.org/doi/abs/10.1021/es2038432

 

Argonne National Laboratory, Grid realities cancel out some of wind power’s carbon savings, May 29, 2012; http://www.anl.gov/articles/grid-realities-cancel-out-some-wind-power-s-carbon-savings

 

Forbes, Wind Power May Not Reduce Carbon Emissions As Expected: Argonne, May 30, 2012; http://www.forbes.com/sites/jeffmcmahon/2012/05/30/wind-power-may-not-reduce-carbon-emissions-argonne/

 

Aol Energy, A Brave New World: Renewable Energy Without Subsidies, June 6, 2012; http://energy.aol.com/2012/06/06/a-brave-new-world-renewable-energy-without-subsidies/#page1?icid=apb1

 

Bloomberg, Renewable-Power Boom Leaves Nations Without Backup, Report Shows, June 8, 2012; http://www.bloomberg.com/news/2012-06-08/renewable-power-boom-leaves-nations-without-backup-report-shows.html

 

Climate Wire, Renewable Energy: Wind power may not reduce carbon emissions as expected, June 1, 2012; http://www.eenews.net/climatewire/2012/06/01/8

 

Source:  Willem Post | theenergycollective.com 1 July 2012

This article is the work of the source indicated. Any opinions expressed in it are not necessarily those of National Wind Watch.

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