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. http://www.iso-ne.com/nwsiss/grid_mkts/enrgy_srcs/index.html

 

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. http://www.ge-flexibility.com/products/flexefficiency_50_combined_cycle_...

 

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. http://www.repartners.org/pdf/coalwind.pdf

 

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

 

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.    http://integrating-renewables.org/grid-impacts/

 

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.  http://www.energytransition.msu.edu/documents/ipu_eia_electricity_genera...

 

SUMMARY OF STUDY RESULTS

 

Various aspects of wind energy on the NEEG, including capital costs, fuel requirements and CO2 emissions reduction were studied. A comparison of the two alternatives was made. In this section are summarized the main results of the study. 

 

Owning and O&M Costs of Wind Turbine Facility Plus Balancing Facility Versus CCGT Facility Plus Increased Energy Efficiency


Wind Turbine Facility Plus Balancing Facility

 

Wind turbine facility capital cost = 10,000 MW x $2,500,000/MW = $25 billion. 

Wind turbine facility useful service life is about 20-25 years.

Wind turbine facility energy production = 10,000 MW x 8,760 hr/yr x CF 0.31 = 27,156 GWh/yr*

 

Balancing facility capital cost = 10,000 MW CCGT x $1,250,000/MW = $12.5 billion.

Balancing facility useful service life is about 30-35 years; short because of balancing.

Balancing facility energy production = 10,000 MW x 8,760 hr/yr x (1.0 - 0.31) = 60,444 GWh/yr

Balancing facility CO2 emissions = 63,399 million lb of CO2/yr. 

Balancing Facility fuel costs = $2,167 million/yr

Extra annual costs for ISO-NE operating costs to deal with wind power.^

 

Capital cost of expanded overlay and T&D systems about $19 to $25 billion (source: NEWIS report) 

Capital cost of expanded weather prediction facility.^

Capital costs of increased frequency regulation capacity.^

 

Annual owning and O&M costs of wind turbine facilities^

Annual owning and O&M costs of balancing facilities.^

Annual owning and O&M costs of expanded overlay grid and T&D systems.^

Annual owning and O&M costs of expanded weather prediction facility.^

Annual owning and O&M costs of increased frequency regulation capacity.^

 

Adverse impacts on quality of life (noise, visuals, psychological), property values and the environment: significant over a large area.

 

CCGT Facility Plus Increased Energy Efficiency

 

CCGT facility capacity = (27,156 +60,444) GWh/yr x 1,000 MW/GW)/(8,760 hr/yr) = 10,000 MW

CCGT facility capital cost = 10,000 MW x $1,250,000/MW = $12.5 billion.

CCGT facility useful service life is about 35-40 years. 

CCGT facility energy production = 87,600 GWh/yr*   

CCGT base-loaded CO2 emissions = 64,779 million lb of CO2/yr #

CCGT base-loaded fuel cost = $2,215 million/yr   

 

Capital cost for expanded overlay grid and T&D systems: minimal compared to Alt. No. 1 

Annual owning and O&M costs of CCGT facility: less than Alt. No. 1

Annual owning and O&M costs of built-out T&D systems: minimal compared to Alt. No. 1

 

Adverse impacts on quality of life (noise, visuals, psychological), property values and environment: minimal compared to Alt. No. 1

 

* the CF gradually decreases as the facilities age.

# this reduction reduces the NEEG average of 1.0 lb of CO2/kWh.

+ the balancing facility produces 60,444 GWh/yr of energy to balance 27,156 GWh/yr of wind energy; together they are seen by the grid as a base-loaded source.

^ not quantified in this study. 

 

Capital Cost                        Alt. No. 1                   Alt. No. 2

                                             $billion                      $billion

 

Wind facility                          25.0

Balancing Facility                   12.5

T&D build-out                        19-25

CCGT                                                                     12.5            

 

Note: the above production quantities require the capacities of the generation facilities of both alternatives to be about 5 to 10 percent greater to account for scheduled and unscheduled outages which will increase the above capital costs and owning and O&M costs.

 

Conclusions and Recommendations

 

- Alt. No. 1 would produce (87,600/130,000) GWh/yr = 67.3% of the energy on the NEEG energy at a cost of about $0.10/kWh.

- Alt. No. 2 would produce (87,600/130,000) GWh/yr = 67.3% of the energy on the NEEG energy at a cost of about $0.0631/kWh.

- Alt. No. 1 has a fuel cost reduction of 2215 - 2167 = $47.2 million/yr, about 2% less than Alt. No. 2

- Alt. No. 1 has a CO2 emissions reduction of 64,779 - 63,399 = 1,380 million lb of CO2/yr, about 2% less than Alt. No. 2

- Alt. No. 1 has a capital cost that is at least $57 - 12.5 = $44.5 billion greater than Alt. No. 2   

- Alt. No. 2 has almost no quality of life (noise, visuals, social unrest), property value and environment impact compared to Alt. No. 1

 

The above comparison of alternatives indicates: 

 

- the combination of wind facilities +balancing facilities is significantly less economical than using the balancing facility at rated output in base-loaded mode.

- the extremely small additional CO2 emissions reduction of Alt. No. 1 is achieved at a huge additional capital cost. 

- the huge capital cost difference of $44.5 billion could be much more effectively used for investments in increased energy efficiency which would more effectively reduce energy costs and CO2 emissions per invested dollar.

- it is extremely unwise economic policy to subsidize the combination of wind facilities with CCGT balancing facilities that would produce energy at a cost about 0.10/0.0631 x 100% = 58% greater than if the same CCGT balancing facility were operated at rated output in base-loaded mode.

- a much better economic and CO2 emissions reduction policy would be to add Alt. No. 2 to the existing low-cost, CO2-free nuclear energy and the existing low-cost, CO2-free hydro energy of Hydro-Quebec and New England. 

 

Another major negative of wind energy is that usually most of it is generated during nighttime. To make the nighttime wind energy available during the daytime, it would first need to be balanced by CCGT facilities (assuming hydro facilities for balancing are not available), then the balanced wind energy would be used to power air compressors to send highly pressurized air into an underground cavern, and then, by decompressing the air through yet another power generating facility, the wind energy would be available for daytime use. This makes Alt. No. 1 even less attractive compared to Alt. No. 2.

 

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

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

http://www.telegraph.co.uk/news/worldnews/europe/denmark/7996606/An-ill-wind-blows-for-Denmarks-green-energy-revolution.html

 

CO2 Reduction Using OCGT, CCGT and Coal Plants for Balancing: PSCO of Colorado and ERCOT of Texas use a mix of OCGT, CCGT and coal plants for balancing which produces CO2 emissions and other pollutants (SOX, NOX, particulate) that are significantly greater/kWh than without balancing, because the coal plant combustion systems and air quality control systems become unstable; they are highly unsuitable for frequent, rapid balancing. See Bentek study below.

 

A better approach would be for PSCO and ERCOT to retire older coal plants that have efficiencies of about 30% and emit at least 2.15 lb of CO2/kWh and replace them with utility-owned, gas-fired CCGTs that have efficiencies of up to 60% and emit about 0.67 lb of CO2/kWh. The CCGTs have short installation periods and capital costs of about 1,250/kW. With wind energy absent, this measure would reduce the most CO2/kWh at the least $/kWh and would produce power at the least $/kWh.  http://theenergycollective.com/willem-post/59747/ge-flexefficiency-50-cc....

 

STUDY PURPOSE AND APPROACH

 

The purpose and approach of this study is to:

 

- compare the owning and O&M costs of wind turbine facilities plus balancing facilities versus CCGT facilities only.

- determine the capacity of the balancing facility required to accommodate any wind energy changes. 

- determine the impacts of several small, medium and large wind energy decreases.

- determine wind energy accommodation fees

- summarize the Bentek study “How Less Became More” regarding using coal plants to accommodate wind energy in Colorado and Texas.

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

 

THE WIND TURBINE FACILITY 

 

Capacity: A 10,000 MW wind turbine facility was chosen because the onshore wind power capacity of New England sites with Wind Class 3, 4, 5, 6, 7 winds is estimated at 10,989 MW. Wind Class 3 is usually considered adequate for community-scale wind facilities and Wind Classes 4 and greater are usually considered essential for utility-scale wind turbine facilities. See page 4 of    http://www.iso-ne.com/committees/comm_wkgrps/othr/sas/mtrls/may212007/le...

 

Production: If 10,000 MW of wind turbine facilities are implemented in the NEEG service area, the production would be 10,000 MW x 8,760 hrs/yr x New England average CF 0.31 = 27,156 GWh/yr, about 27,156/130.000 = 20.9% of current consumption.  

 

Capacity Factor: A New England average CF = 0.31 was chosen because early installed wind turbine facilities would likely be on ridge lines with higher CFs, such as facilities in western Maine which have an average CF = 0.32, whereas later installed facilities would be on ridge lines with CFs of 0.30 or less.   http://www.coalitionforenergysolutions.org/maine_wind_farms.pdf

 

Some wind power proponents make optimistic statements regarding CFs calculated from wind speed measurements for a period of one to three years, but actual operating experience proves otherwise. The lower CFs are partially due to wind power curtailments to avoid excessive balancing stresses on the power plants connected to the grids, stresses on transmission systems and increased O&M downtime.

 

For example: In Denmark, the outputs of wind turbines are reduced to avoid excessive wind energy increases that would overwhelm Denmark's’ small grid and that are not wanted by Norway, Sweden and Germany for various reasons.

 

The New England average CF = 0.31 may prove to be very optimistic, because large geographical areas rarely have capacity factors greater than 0.30. For comparison: Western Ireland (0.323 for the 2002-2009 period, the best in Europe, see website), UK (0.282 for 1998-2004), Texas (0.258 for 2009), Denmark (0.242 for the 2005-2009 period), the Netherlands (0.186), Germany (0.167). It would not be credible to aver onshore wind speeds in New England are comparable to onshore wind speeds in western Ireland, one of the windiest areas of Europe.

http://www.seai.ie/Renewables/Wind_Energy/Wind_Energy_Annual_Reports/2009_Wind_Energy_Annual_Report.pdf

 

Capital Cost: The capital cost of the wind turbine facility would be 10,000 MW x $2,500,000/MW = $25 billion. An installed capital cost of $2,500,000/MW was chosen for this study. It is the same as the average of the capital costs of the recently installed operating and planned wind turbine facilities in Maine and less than the $2,778,000/MW of the Granite Reliable Power Windpark, Coos County, NH, consisting of 33 Vestas units @ 3 MW each.   http://www.coalitionforenergysolutions.org/maine_wind_farms.pdf

 

O&M Costs: O&M costs are related to a limited number of cost components, including: insurance, regular maintenance, repair, spare parts, and administration.

The standard warranty of an onshore, utility-scale wind turbine is about 2 years. After that period owners are vulnerable to significant O&M costs for gearboxes, generators, drive trains and blades. For example: A gearbox changeout may cost $500,000 and up, plus about 30 days of down time. Gearboxes and blades sometimes fail within 2 -3 years. Extended warranties are available at significant fees.

 

The average O&M costs of onshore, utility-scale wind turbines is about 2.7 cents/kWh; the O&M costs are from actual cost data of existing wind turbine facilities throughout the world. See below websites.

 

The 2.7 cents/kWh is about 3 to 5 times the values typically used in spreadsheets of wind turbine vendors and project developers to attract investors, secure financing and obtain government approvals. 

 

If the O&M costs of Kansas wind turbine facilities is used as a base, then the O&M costs on New England ridge line wind turbine facilities are about 2 times Kansas and the O&M costs of offshore facilities are about 3-4 times Kansas. Kansas was chosen as a base because it is flat and easily accessable for O&M, i.e., low owning costs/MWh and low O&M costs/MWh.

 

O&M increases with wind turbine age: a lifetime average of 20 - 25 percent of the levelized cost/kWh, starting at about 10 - 15 percent for unsubsidized newer units, gradually increasing to 20 - 35 percent for unsubsidized older units.

 

http://www.renewableenergyworld.com/rea/partner/first-conferences/news/article/2010/06/true-cost-of-wind-turbine-operations-maintenance

http://www.croh.info/index.php?option=com_content&view=article&id=1402:prwebcom-newswire-httpwwwdigitaljournalcom&catid=10:news

http://spectrum.ieee.org/energywise/green-tech/wind/trouble-brewing-for-wind

http://www.slideshare.net/WindEnergyReports/summary-the-wind-energy-operations-maintenance-report 

 

Location: As the ridge lines in New England have the best winds, it is assumed almost all wind turbines would be located on them. If the wind turbines are a 50/50 mix of 2.5 MW and 3 MW units, then about 10,000 MW/(0.5 x 2.5 + 0.5 x 3.0) MW  = 3,636 units/(7 units per mile of ridge line) = 520 miles of ridge line would be required. 

 

The wind turbines would be located in areas with the best winds, such as on the ridge lines of the north-south spine of Vermont, northern New Hampshire and western Maine; the latter two areas have greater average wind speeds than Vermont. With enough subsidies and generous PPAs, even IPP-owned wind turbine facilities in Vermont will be profitable.

 

Such a concentration of wind turbine facilities would yield less of a reduction of wind energy variability normally associated with widespread geographic distribution of wind turbine facilities, i.e., the variability of wind energy would be reduced if some areas temporarily seeing higher wind speeds are combined with areas simultaneously seeing lower speed winds. Whereas this concept appears plausible in theory, in practice it has not been proven because typical weather systems extend 500 to 1,000 miles.  

 

The 2.5 MW and 3 MW units are about 390 to 466.5 ft tall to the tip of the blade, respectively, which would appear very large if the ridge line is at 2,000 ft elevation and a person’s house is at 1,000 ft elevation and within a mile of a row of wind turbines; at night there would be an unsteady beat of annoying/disturbing whoosh sounds. Wind turbines are often made to look small on distant ridge lines using Adobe’s Photoshop software.

 

Energy Used by Wind Turbines (Parasitic Energy): One of the big secrets of the wind industry is wind turbine parasitic energy. Little information can be found on the internet. Yet, all of the information would be revealed if a proper wiring diagram were published and some real-time measurements were made.

 

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

 

In winter, the wind speed has to be well above 4.5 m/s, or 10.7 miles/hour, to offset the parasitic energy. Speeds less than that means drawing from the grid, speeds greater than that means feeding into the grid. 

 

This will significantly reduce the net wind energy produced during a winter. On cold winter days the nacelle (on big turbines the size of a Greyhound bus) and other components require significant quantities of electric energy.

 

Below is a representative list of equipment and systems that require electric energy; 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 to 20 percent of the turbine rated output

- 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.

http://www.aweo.org/windconsumption.html

 

Do wind turbine facility owners pay for the energy drawn from the grid, or is this just another hidden subsidy?

 

BALANCING FACILITY FOR ACCOMMODATING WIND ENERGY TO THE GRID 

 

The two main ways of economically accommodating wind energy are hydro power facilities and gas turbine facilities. Spain and Portugal use both, Denmark and the Bonneville Power Authority use hydro. See below website.

http://theenergycollective.com/willem-post/46977/impacts-variable-intermittent-power-grids

 

Two examples of balancing facilites to accommodate wind energy are described:

 

Denmark and Hydro Plant Balancing Facility

 

Denmark’s prevailing winds are from the North Sea, across Denmark, to the Baltic Sea. The best winds are on Denmark’s northwest coast. Denmark has more than 4,000 onshore wind turbines with a capacity of about 3,150 MW, nearly unchanged since the end of 2003. About 90% of the onshore wind turbines are supplied by Vestas. The increases in capacity in 2009 and 2010 are due to offshore wind turbines almost all supplied by Siemens.  

 

High Wind Speed Periods: If the wind blows strongly in Denmark, and as the marginal cost of operating wind turbines is near zero (i.e., ignoring non-variable capital and O&M costs), there is a big incentive to maximize wind energy even if it is not needed by the Danes, such as during low demand periods. 

 

To avoid disturbances on the small Danish grids and excessive balancing operations by the hundreds of small combined-heating-power, CHP, plants, the large wind energy surges are accommodated by the much larger Scandinavian grid by using the hydro plants of Norway and Sweden as balancing plants.

http://en.wikipedia.org/wiki/Hydroelectricity#Pumped-storage

 

Studies of grid operating data show that Denmark exports electricity to Norway and Sweden, and that those exports are highest during strong wind periods. This saves water that is used for subsequent energy production. 

 

http://www.cedren.no/News/Article/tabid/3599/ArticleId/1079/Can-Norway-be-Europe-s-green-battery.aspx

http://www.globaltransmission.info/archive.php?id=1424

 

However, sometimes they refuse to take some of the Danish wind energy. In that case grid operators who control the wind turbines in Denmark will reduce the output of a percentage of them (by feathering the blades or stopping them), according to pre-planned sequences. 

 

Low Wind Speed Periods: During low wind energy periods the hundreds of small CHP plants and a few big central power plants perform the wind energy balancing function. 

 

This back-and-forth operation is inefficient and uneconomical, as various studies have shown. One indication of this inefficiency: Denmark has the highest residential electric rates in Europe, whereas its commercial rates are kept at about one third of the residential rates for international competitive reasons. France, 80% nuclear, has one of the lowest electric rates in Europe.  

 

It is difficult to compare electric rates between nations, such as France, Denmark, the US Northeast, etc. The total cost of electricity is influenced by many factors not related to fuel costs. France, Denmark, etc., add fees and value added taxes, VATs, to electric bills, some or all of the fees and VAT COULD be used to subsidize renewables.

 

http://www.cedren.no/News/Article/tabid/3599/ArticleId/1079/could-Norway-be-Europe-s-green-battery.aspx

http://www.globaltransmission.info/archive.php?id=1424

http://www.cepos.dk/fileadmin/user_upload/Arkiv/PDF/Wind_energy_-_the_case_of_Denmark.pdf

http://theenergycollective.com/willem-post/46977/impacts-variable-intermittent-power-grids

http://theenergycollective.com/willem-post/51642/dutch-renewables-about-face-towards-nuclear

http://truenorthreports.com/uk-wind-power-not-making-the-grade

 

ISO-NE and Wind Energy Balancing Options 

 

Because the NEEG has little hydro plant capacity connected to it, the least costly, least polluting, most suitable way of balancing wind energy is not available to the ISO-NE, unless Hydro-Quebec performs this service for a fee.

 

Accordingly, the NEEG would need other, quick-starting, quick-ramping power plants for balancing wind energy. The least costly, least polluting and most efficient power plants for this purpose are gas-fired CCGTs. The plants can also be operated as OCGTs by bypassing the HRSG. Utility-owned CCGT plants would be available for balancing wind energy; any extra costs would likely be rolled into the electric rate schedules. Privately-owned CCGT plants would likely perform balancing wind energy for a fee.

 

New England’s current CCGT capacity is distributed as follows: CT 1491 MW , MA 5283 MW, ME 790 MW, NH 1289.5 MW and RI 693 MW, VT 0 MW, for a total of about 9,546.5 MW, all privately-owned. This capacity produces about 0.44 x 130,000 GWh/yr = 57,200 GWh/yr, for an average capacity factor of about (57,200 x 1,000 MWh/1 GWh)/(8,760 x 9,500) = 0.687   

 

THE BALANCING FACILITY

 

Capacity and Production: ISO-NE would need to have a quick-starting, quick-ramping cycling facility, consisting of a mix of OCGT and CCGT plants. The facility would produce 10,000 MW x 8,760 x (1.0 - 0.31) = 60,444 GWh/yr of wind balancing energy, about 60,444/130,000 = 46.5% of current NEEG consumption, i.e., a major part of the NEEG energy production would be by the cycling facility that would operate at a significantly lower efficiency than it would if wind energy were entirely absent. As a balancing facility, its CF would be about 1.0 - 0.31 = 0.69, instead of 0.85-0.90, if it were base-loaded. 

 

Such underutilization of a utility-owned asset has a significant owning and O&M costs of which a part should be added to the wind accommodation fees paid by wind turbine facility owners, NOT added to the electric rates of rate payers.

 

Capital Cost: The balancing facility would be 10,000 MW x $1,250,000/MW = $12.5 billion. Any balancing facility must be utility-owned, not IPP-owned, to ensure it is available for balancing operations.

 

Location: At higher wind energy penetration percentages, most wind turbine facilities on the Maine, New Hampshire and Vermont ridge lines would need to feed into new T&D and grid overlay systems which would be connected with new transmission systems to the existing grids serving major population centers, mainly in southern New Hampshire, Massachusetts and Connecticut. The existing grids would need to be redesigned and augmented to enable them to accommodate the wind and balancing energy supply. 

 

The balancing facility would be connected to the new grid overlay systems to balance the wind energy BEFORE it enters the existing grids. If, for example, the new grid overlay systems had 20 connection points to the existing grids, about 5% of the balancing facility could be located at each point. It would be somewhat similar to a new highway system encircling a large metropolitan area with on/off ramp connections to the existing road systems.

 

A part of the balancing facility could be located near the northern ridge lines and supplied with gas from Canada, and the rest of the balancing facility could be located in southern New England and supplied with gas from Pennsylvania. 

 

The energy transmitted by the new T&D and grid overlay systems would be 27,156 GWh/yr, Wind + 60,444 GWh/yr, Balancing = 87,600 GWh/yr, or about 87,600/130,000 = 67.4% of current NEEG supply.

 

The capital cost of the T&D and grid overlay systems would be $19 billion to $25 billion. See below NREL reports.

 

The annual owning and O&M costs of the augmented T&D and grid overlay sytems would be significant. Would owners of wind turbine facilities pay those additional costs as part of accommodating wind energy, or will all this be placed under the heading of “smart grids”?

 

INCREASED FREQUENCY REGULATING CAPACITY WITH INCREASED WIND ENERGY PENETRATION

Quick-ramping, spinning OCGT plants, diesel plants, pumped-hydro, run-of-river hydro, impounded hydro, large capacitors, flywheels, batteries, etc., are necessary to continuously maintain the 60 Hz frequency of the grid within a narrow band. The OCGTs in frequency-response mode, under nominal conditions, would run at reduced output to maintain a buffer of spare capacity and would continually alter their outputs on a second-to-second basis to maintain frequency with a so-called droop speed control. 

 

When the demand exceeds the supply (including back-up spinning reserve), the voltage and frequency drop, which increases the loss-of-load-probability (LOLP). Even small changes in frequency or voltage (either positive or negative) can significantly increase the LOLP; loss of load implies blackouts and/or brownouts.

 

A demand increase, or a supply decrease, or both at the same time, would cause the generators on the grid to slow down. Their synchronizers would sense this and more steam or fuel is supplied to the steam or gas-turbine generators which would increase their RPMs. Some generators are slow to react, others are faster, such as spinning OCGTs, which would immediately ramp up until the others catch up. 

 

Variable wind energy on the grid acts as a supply increaser and supply decreaser 24/7/365 in addition to normal demand and supply variations. Accordingly, greater regulating capacity is required with increased wind energy penetration. 

 

With the current 0.5% of wind energy penetration on the NEEG, the hourly capacity used for frequency regulation varies from a low of 30 MW to a high of 200 MW , a 7:1 ratio. Over all hours of 2008, the weighted average hourly regulation, WAHR, was about 80 MW. The addition of wind power capacity would increase the real-time variability and short-term uncertainty of the electrical energy supply.  See Page 171 of New England Wind Integration Study, NEWIS.

 

Based on a statistical analysis of ISO-NE grid operating data and on various other sources of wind data, the WAHR capacity would increase from the above about 80 MW with current wind energy, to a high of 315 MW at 20% wind energy penetration, 230 MW at 14%, 160 MW at 9% and 100 MW at 2.5%. See page 182 of NEWIS. 

 

The WAHR values are AVERAGES. With 20% wind energy penetration and very large wind speed variations, as often happens in New England, the required frequency regulating capacity may be about 2,000 MW. http://www.beaconpower.com/files/ISO-NE-performance-paper-2010.pdf

 

The annual owning and O&M costs of operating a 4-fold increase in WAHR capacity would be significant. Would owners of wind turbine facilities pay those additional costs as part of accommodating wind energy?

 

INCREASED BALANCING CAPACITY WITH INCREASED WIND ENERGY PENETRATION

 

Normal Demand Following - Without Wind Energy

 

Quick-ramping OCGTs and CCGTs-in-OCGT-mode that normally provide power during peak demand hours of a typical day will have output variations as they ramp up and down to serve normal daily demand. A lesser capacity of OCGTs and CCGTs performs the same service during the other hours of the day. 

 

The output variations are due 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

 

They can be positive or negative, they can be step changes or ramp changes. The smaller changes are smoothed by the inertia of the generators on the grid and by the spinning frequency regulating OCGTs. The larger changes require spinning OCGTs to frequently ramp or down as needed.

 

Because the normal daily demand profile from hour-to-hour and day-to-day is know with some certainty, any normal demand change is also known with some certainty and the appropriate intermediate and peaking plant capacity is deployed to service the changing demand.

 

Normal Demand Following - With Wind Energy

 

The magnitude and duration of large wind energy changes are not known with adequate and timely certainty, especially in an area with highly variable weather, such as New England. 

 

Hundreds of weather stations all over New England, and beyond New England, would be required to monitor atmospheric conditions to predict, using computer programs, hourly forecasts of wind energy output for the next 48 hours, updated every 15 minutes, to be useful to grid operators for making day-ahead, unit-commitment decisions concerning which units to turn on and when to do so.

 

Such wind energy prediction systems are in operation with mixed success in nations with variable weather conditions, such as Denmark, Spain, Germany, England, Ireland, etc. http://docs.wind-watch.org/oswald-energy-policy-2008.pdf

 

The annual owning and O&M costs of such a weather forecasting facility would be significant. Would owners of wind turbine facilities pay those costs as part of accommodating wind energy?

 

Wind Speed Decreases and Balancing Energy  

 

The balancing facility could be operated in various modes at the same time; a percentage of its capacity could be in spinning mode (zero output, similar to idling a car), another percentage could be at a percent of rated output and another percentage could be at rated output, depending on the predicted wind energy to be accommodated.

 

Below are calculated the balancing energy required for predicted small, medium, large and very large wind speed decreases. In each case, the spinning mode is used for calculations, but the mode could be a combination of the above three modes.

 

Small Wind Speed Decrease: predicted weather conditions indicating predicted wind speeds to decrease from 15 mph to less than 7.8 mph lasting about 1 hour, requiring at least 10% of the balancing facility to be in spinning mode. Such a wind speed decrease could cause a wind facility output decrease from 1,000 MW to 0 MW , resulting in a wind energy decrease of of 1,000 MW/2 x 1 hr = 500 MWh. About 10% of the balancing facility capacity would be capable of producing 0.1 x 10,000 MW/2 x 1 hr = 500 MWh.  

 

Medium Wind Speed Decrease: predicted weather conditions indicating predicted wind speeds to decrease from 25 mph to less than 7.8 mph lasting about 3 hours, requiring at least 20% of the balancing facility to be in spinning mode. Such a wind speed decrease could cause a wind facility output decrease from about 2,000 MW to 0 MW, resulting in a wind energy decrease of 2,000 MW/2 x 3 hrs = 3,000 MWh. About 20% of the balancing facility capacity would be capable of producing 0.2 x 10,000 MW/2 x 3 hrs = 3,000 MWh   

 

Large Wind Speed Decrease: predicted weather conditions indicating predicted wind speeds to decrease from 35 mph to less than 7.8 mph lasting about 4 hours, requiring at least 40% of the balancing facility to be in spinning mode. Such a wind speed decrease could cause a wind facility output decrease from about 4,000 MW to about 0 MW, resulting in a wind energy decrease of 4,000 MW/2 x 4 hrs = 8,000 MWh. About 40% of the balancing facility capacity would be capable of producing 0.4 x 10,000 MW/2 x 4 hrs = 8,000 MWh.   

 

Very Large Wind Speed Decrease: predicted weather conditions indicating a significant weather front moving through New England with predicted wind speeds to decrease from about 45 mph to less than 7.8 mph lasting about 6 hours, requiring at least 80% of the balancing facility to be in spinning mode. Such a wind speed decrease could cause a wind facility output decrease from about 8,000 MW to 0 MW, resulting in a wind energy decrease of 8,000 MW/2 x 6 hrs = 24,000 MWh. About 80% of the balancing facility capacity would be capable of producing 0.8 x 10,000 MW/2 x 6 hrs = 24,000 MWh. 

 

The average energy supply of the NEEG during a 6 hour period is (130,000 GWh/yr)/(365 d/yr) x 0.25d = 89,041 MWh/d. The above large and very large wind energy decreases would have major impacts on the NEEG grid without a utility-owned, quick-ramping balancing facility to accommodate the wind energy decrease. Additionally, during large and very large wind speed events, it is not unusual to have electric supply interruptions due to falling trees, etc., which further stress the grid.  

 

Because the grids of Colorado and Texas lack adequate, utility-owned, quick-ramping balancing facilities, coal plants, not designed for quick-ramping, have been used for accommodating wind energy with unsatisfactory results. See below summary of the Bentek report.

 

Note: wind energy is produced irregularly during a year. For example: 

 

- no wind energy is produced at wind speeds below 3.5 m/sec (7.8 mph) about 10% of the time  

- wind energy is produced at less than 10% of rated output about 30% of the time 

- wind energy is produced at less than 31% of rated output (CF level) about 70% of the time

- wind energy is produced at greater than 31% about 30% of the time. Most of the larger amplitude balancing occurs during this period.  

 

http://www.wind-watch.org/documents/analysis-of-uk-wind-power-generation-november-2008-to-december-2010/

http://docs.wind-watch.org/john-muir-trust-wind-report.pdf

 

Balancing Energy to Accommodate Wind Energy

 

Wind energy is proportional to the cube of wind speed, a doubling of wind speed, which are frequently occurring events during a day, would increase wind energy 8-fold. Wind energy often varies by a factor of ten or more during an hour which is quite shock to the stability of electric grids if a balancing facility with adequate quick-ramping capacity is not available. In New England, such a wind event may occur when a rainstorm with lightning passes through. It starts with nearly no wind, then suddenly strong winds, much rain and lightning, and then almost no wind.

 

Adequate capacity of quick-ramping, spinning plants must be deployed, if the monitored atmospheric conditions give any indications of sudden, large wind energy changes; any such deployment must err on the safe side to avoid brownouts, etc. 

 

If the balancing plants were to run out of ramping range, i.e., reach rated output, because wind energy decreased too much, then wind turbine output curtailment by feathering the rotor blades or stopping them (practiced in Denmark, Spain, Portugal, Germany, Texas, etc.) and demand curtailment by load-shedding would be required. http://www.masterresource.org/2011/04/renewable-lawsuit-colorado/

 

Less such balancing capacity would be required if energy could be drawn from and sent to other grids that are connected to the NEEG and if hydro plants, such as of Hydro-Quebec, HQ, would be available for balancing operations. However, the other grids and the HQ service area would likely have their own wind turbine facilities and may not have, nor be willing to share, spare capacity for NEEG balancing operations. Hence, the generating capacity of the NEEG would need to include sufficient quick-starting, quick-ramping plant capacity to provide energy when big decreases in wind energy occur. See Fig 1 of   http://inside.mines.edu/~dkaffine/WINDEMISSIONS.pdf 

 

Wind turbine facility IPPs could present a less variable output to the grid, such as by feathering their rotor blades and/or adding balancing plants consisting of diesel-generators or OCGTs to limit minute-by-minute ramp rates of the combined output. However, IPPs might object, as it would increase their owning and O&M costs; additional subsidies may be needed as an incentive.

 

Ireland enacted a new grid code in 2004 that requires wind turbine facilities to reduce the variability of their outputs, i.e., be more “grid-friendly.” See Page 17 of http://www.ref.org.uk/attachments/article/171/david.white.wind.co2.savin...

 

Increased Balancing Energy With Increased Wind Energy Penetration 

 

A spreadsheet for 0.5%, 1, 2, 3,....... to 20.9%  wind energy penetration was prepared to illustrate the rapid decrease of available balancing energy and increase of wind energy accommodation costs with increasing wind energy penetration; the 0.5% corresponds to the about 239 MW of wind power capacity currently on the NEEG and the 20.9% corresponds to the 10,000 MW wind power capacity of this study.  http://www.coalitionforenergysolutions.org/sp-balancing_range_co2-1.pdf

 

Without Wind Energy: the energy supplied to the NEEG is about 130,000 GWh/yr of which about 54%, or 70,200 GWh/yr, is base-loaded (nuclear and coal; IPP-owned hydro and gas plants; Hydro-Quebec, etc. If about 30% x 130,000, or 39,000 GWh/yr, is supplied by utility-owned plants for intermediate and peaking energy to follow the daily demand, then about 16% x 130,000, or 20,800 GWH/yr, is non-base-load energy supplied by other IPP and utility-owned plants.

 

With Wind Energy: the energy supplied to the NEEG is about 130,000 GWh/yr of which about 54% + (wind + balancing)% is base-loaded, or 70,200 + 650 + 1,447 = 72,279 GWh/yr, at 0.5% wind energy penetration; wind energy plus balancing energy is equivalent to a base-loaded plant. Non-base-load energy is 130,000 - 72,279 = 57,703 GWh/yr, of which about 39,000 GWh/yr is required to follow daily demand, leaving 57,703 - 39,000 = 18,703 GWh/yr as non-base-load energy supplied by other plants. There must always be at least 39,000 GWh/yr, plus a margin in case of plant outages, of non-base-load energy for daily demand following.

 

The supply of utility-owned, base-loaded energy can be reduced (the IPPs are not interested in reducing THEIR outputs), and more (wind + balancing) energy can be added to the base-loaded portion until the utility-owned, base-load energy has been reduced to the safe/prudent lower plant operating limits. This means low-cost, base-loaded energy is replaced by high-cost, base-loaded energy which will increase electric rates. 

 

Because the ISO-NE knows the exact ownership and capabilities of the 350 plants tied to the NEEG, it can quantify the available balancing energy to accommodate increasing percentages of wind energy penetration.

 

http://theenergycollective.com/willem-post/46977/impacts-variable-intermittent-power-grids

http://www.nrel.gov/docs/fy06osti/39524.pdf

http://www.fileden.com/files/2009/6/11/2474018/nofreewind/Cali-wind.jpg

https://wpweb2.tepper.cmu.edu/ceic/PDFS/CEIC_10_01_CWV.pdf

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

 

NEEG System Conditions and Increased Wind Energy Penetration

 

Grids with a significant utility-owned OCGT and CCGT generating capacity, such as the NEEG, may have sufficient spare balancing capacity to accommodate up to about 1 to 2 percent of wind energy penetration. In New England, currently at about 0.5% penetration, its presence on the grid is not yet "noticeable”, according to ISO-NE personnel. The main reason it is not noticeable is because of a lack of proper data measuring and recording of power plant operating data. As wind energy penetration becomes larger, say 1%, wind energy variations WILL become noticeable, especially during unstable weather. 

 

At night, when demand is low, spare balancing capacity would likely be available because only a small part of the OCGT/CCGT capacity would be used for demand following, but during daytime peak demand periods most of the OCGT/CCGT capacity would be used for demand following and would likely not be available for balancing to accommodate wind energy. A mitigating factor regarding balancing capacity is that wind energy is often greater at night than during the day.

 

Significant slow-ramping power generation capacity on the NEEG, such as nuclear and coal plants, cannot be used for balancing. Among the remaining generation capacity, only the part capable of quick-ramping could be used for balancing. Attempts in Colorado and Texas to use base-loaded coal plants for balancing proved less than satisfactory, especially during unstable weather. See Bentek report below.

 

IPPs in Maine are planning to install 2,000 MW of onshore wind turbines by 2015 which would result in about 4% wind energy penetration on the NEEG. However, the spreadsheet shows the spare balancing energy of the existing plants on the NEEG would allow only about 2 to 3 percent wind energy penetration. 

 

This means NEEG utilities would need to install additional utility-owned OCGT and CCGT facilities and T&D systems to accommodate the wind energy of the 2,000 MW of wind turbines by 2015. The capital costs and the owning and O&M costs of the gas turbine facilities and T&D systems will ultimately result in significant additions to electric rates. 

 

Wind turbine vendors, developers and financiers are aware of the near-term lack of spare balancing energy in the NEEG system and are rushing to get their projects built before it becomes common knowledge. 

 

GAS TURBINE HEAT RATES 

 

The gas turbines of the balancing facility, most efficient near rated output, would have to operate at a less efficient, more polluting, reduced output to be able to immediately vary their outputs to accommodate all variations of wind energy, including unpredictable, sudden, large variations of wind energy. 

 

Gas turbine heat rates, Btu/kWh, and CO2 emissions, lb of CO2/kWh, increase because of increased inefficient operation below rated output of OCGTs, and CCGTs operating as OCGTs. 

 

For example: at 80, 50 and 20 percent of rated output, the heat rates are equal to the rated heat rate divided by 0.95, 0.85 and 0.55, respectively, or a heat rate degradation of (1/0.95 - 1) x 100 = 5.3%, 17.6%, and 81.8% respectively.

 

Gas turbines are rarely operated below 40% of rated output, because of much degraded heat rates. This is for steady operation at a percentage of rated output. If the balancing facility is operating at a percentage of rated output AND irregularly and rapidly ramping up and down, the heat rate degradation increases further.

 

For example: If a gas turbine rapidly cycles from 60% down to 40% and back up to 60%, 5 minutes at 15MW/min down, 5 minutes up at 15 MW/min, its roundtrip fuel consumption and CO2 emissions are about 20% greater than if it had operated at 100% for the same 10 minutes. The average output was 50% which would have a steady heat rate degradation of about 17.6%, plus a rapid-ramping degradation of, say 2 - 3%, for a total of about 19.6 - 20.6 percent. 

 

Existing gas turbines are designed to perform a few cycles per day. Cycling at least a hundred times per day to balance wind energy will significantly increase wear and tear, i.e., (owning + O&M) costs and electric rates.

 

http://www.ge-mcs.com/download/bently-nevada-software/1q05_performancemonitoring.pdf

http://www.etsap.org/E-techDS/PDF/E02-gas_fired_power-GS-AD-gct.pdf

 

For example: a car driven on a level road at a steady speed of 40 mph has a mileage of, say 26 mpg. The same car driven on a level road at irregular and rapidly changing speeds that average 40 mph has a mileage of, say 22 mpg. The mileage degradation due to the speed changes would be (26-22)/26 x 100% = 15%. A car’s best mileage usually is at 55 mph, at a steady speed, on a smooth and level road; it is the oft-quoted EPA highway mileage.

 

For this study it is assumed the heat rate degradation factors are:

 

- irregularly and rapidly ramping up and down: 0.90 for CCGT and 0.85 for OCGT operation

- reduced output operation: 0.90 for CCGT and 0.85 for OCGT operation 

 

For this study heat rates and CO2 emissions used are:

 

Alt. No. 1: Irregular Ramping Up and Down Mode and Part-Loaded Mode

 

CCGT heat rate = (3,413 Btu/kWh/(eff 0.60 x balancing 0.90 x reduced output 0.90) = 7,023  Btu/kWh

CO2 emissions/kWh = 117 lb of CO2/(million Btu x 1 kWh/7,023 Btu) = 0.822 lb of CO2/kWh

 

OCGT heat rate = (3,413 Btu/kWh)/eff 0.35 x balancing 0.85 x reduced output 0.85) = 13,497 Btu/kWh 

CO2 emissions/kWh = 117 lb of CO2/(million Btu x 1 kWh/13,497 Btu) = 1.579 lb of CO2/kWh

 

Alt. No. 2: Base-Loaded and Part-Loaded Mode 

 

CCGT heat rate = (3,413 Btu/kWh/eff0.60 x reduced output 0.90) = 6,320  Btu/kWh

CO2 emissions/kWh = 117 lb of CO2/(million Btu x 1 kWh/6,320 Btu) = 0.739 lb of CO2/kWh

 

OCGT heat rate = (3,413 Btu/kWh)/efficiency 0.35 x reduced output 0.85) = 11,472  Btu/kWh 

CO2 emissions/kWh = 117 lb of CO2/(million Btu x 1 kWh/11,472 Btu) = 1.342 lb of CO2/kWh

 

FUEL CONSUMPTION AND COST

 

Alt. No. 1, Wind + Balancing: Assuming an operating basis of 30% OCGT mode and 70% CCGT mode, the fuel cost of the balancing facility would be 60,444 GWh/yr x (0.30 x 11,472 + 0.70 x 6,320) Btu/kWh x $4/1,000,000 Btu = $2,167 million/yr

 

Alt. No. 2, CCGT Only: Assuming base-loaded and part-loaded mode, the fuel cost of the CCGT facility would be (27,156 + 60,444) GWh/yr x 6,320 Btu/kWh = $2,215 million/yr 

 

The fuel cost reduction due to adding wind energy = 2,167 - 2,215 = $47 million/yr, about 2%

 

CO2 EMISSIONS

 

Alt. No. 1, Wind + Balancing: Assuming an operating basis of 30% OCGT mode and 70% CCGT mode, the CO2 emissions of the balancing facility would be 60,444 GWh/yr x (0.30 x 1.342 + 0.70 x 0.739) lb of CO2/kWh = 63,399 million lb of CO2/yr

 

Alt. No. 2, CCGT Only: Assuming base-loaded and part-loaded mode, the CO2 emissions of the CCGT facility would be (27,156 + 60,444) GWh/yr x 0.739 lb of CO2/kWh = 64,779 million lb of CO2/yr 

 

The CO2 emission reduction due to adding wind energy = 64,779 - 63,399 = 1,380 million lb of CO2/yr, about 2%   

 

Note: the output variations could be monitored and recorded, at one-minute intervals, at the wind turbine facilities. The variations in fuel consumption could be monitored and recorded, at one-minute intervals, and correlated with other data to accurately determine the fuel consumption and CO2 emissions to accommodate wind energy. 

 

If a mix of OCGT, CCGT and coal plants were used, as in Colorado and Texas, the extra CO2 emissions, and other pollutants, due to cycling would be significantly greater/kWh, because coal plants and their air quality control systems are highly unsuitable for frequent, rapid, larger-amplitude cycling. See Bentek study below.

 

BALANCING WIND ENERGY IN COLORADO AND TEXAS

 

Because the NEEG has very minor wind energy penetration, there would be no data to study fuel consumption and CO2 emissions related to balancing plants to accommodate wind energy, as there are in other jurisdictions. Accordingly, a recent study of Colorado and Texas, both states with significant wind turbine facilities, is used to illustrate some impacts of wind energy on plant operations.

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

 

Colorado  

 

Public Service of Colorado, PSCO, owns insufficient gas-fired CCGT capacity for balancing to accommodate wind power. Instead, it is attempting to use its own coal plants for balancing for which they were not designed and for which they are highly unsuitable. The results have been significantly increased pollution and CO2 emissions per kWh.

 

The heat rate of a coal plant operated near rated output it is about 10,500 Btu/kWh for power delivered to the grid. It is lowest near rated output and highest at very low outputs. If a plant is rapidly ramped up and down in balancing mode at a percent of rated output, its heat rate rises. See Pages 26, 28, 35, 41 of the Bentek study.  

 

On Page 28, the top graph covering all PSCO coal plants shows small heat rate changes with wind power outputs during 2006. The bottom graph shows greater heat rate changes with wind power outputs during 2008, because during the 2006-2008 period 775 MW of wind facilities was added. For the individual PSCO plants doing most of the balancing, the heat rate changes are much higher. 

 

On Page 26, during a coal plant ramp down of 30% from a steady operating state to comply with the state must-take mandate, the heat rate rose at much as 38%.

 

On Page 35, during coal and gas plant ramp downs, the Area Control Error, ACE, shows significant instability when wind power output increased from 200 to 800 MW in 3.5 hours and decreased to 200 MW during the next 1.5 hours. The design ramp rates, MW per minute, of some plants were exceeded.

 

On Page 41, during coal plant balancing across the PSCO system due to a wind event, emissions, reported to the EPA for every hour, showed increased emissions of 70,141 pounds of SOX (23% of total PSCO coal emissions); 72,658 pounds of NOX (27%) and 1,297 tons of CO2 (2%) than if the wind event had been absent.

 

Those increases of CO, CO2, NOX, SOX and particulate per kWh are due to instabilities of the combustion process during balancing; the combustion process can ramp up and down, but slowly. As the varying concentration of the constituents in the flue gases enter the air quality control system, it cannot vary its chemical stoichiometric ratios quickly enough to remove the SOX below EPA-required values. These instabilities persist well beyond each significant wind event. 

 

PSCO does not release hourly wind power generation data. Such information is critical for any accurate analysis and comparison of alternatives to reduce such emissions; deliberately withholding such information is inexcusable.

 

Texas

 

The Texas grid in mostly independent from the rest of the US grids; the grid is operated by ERCOT. The grid has the following capacity mix: Gas 44,368 MW (58%), Coal 17,530 MW (23%), Wind 9,410 MW (12% - end 2009), Nuclear 5,091 MW (7%). Generation in 2009 was about 300 TWh. By fuel type: Coal 111.4 TWh, Gas CCGT 98.9 TWh, Gas OCGT 29.4 TWh, Nuclear 41.3 TWh, Wind 18.7 TWh.  Summer peak of 63,400 MW is high due to air conditioning demand. 

 

Wind provides 5 to 8% of the average generation overall, depending on the season. Its night contribution rises from 6% (summer) to 10% (spring). Texas capacity CF = 18.7 TWh/yr/{(9,410 + 7,118)/2) MW x 8,760 hr/yr)} = 0.258. Texas has excellent winds and should have a statewide CF of 0.30 or greater. Explanations for the low CF likely are:

 

- grid operator ERCOT requires significant curtailment of wind energy to stabilize the grid. 

- vendors, developers and financiers of wind power facilities, eager to cash in on subsidies before deadlines, installed some wind turbine facilities before adequate transmission capacity was installed to transmit their wind output to urban areas.

 

Much of the gas-fired capacity consists of CCGTs that are owned by IPPs which sell their power to utilities under PPAs. That capacity is not utility-owned and therefore not available for balancing to accommodate the output of more than 10,000 MW of wind power facilities. Instead, utilities are attempting to use coal plants for balancing for which they were not designed. The results have been significantly increased pollution and CO2 emissions.

      

Unlike PSCO, ERCOT requires reporting of fuel consumption by fuel type and power generation by technology type every 15 minutes. The 2007, 2008, 2009 data shows rising amplitude and frequency of balancing operations as wind energy penetration increased. In 2009, the same coal plants were cycled up to 300 MW/cycle about 1,307 times (up from 779 in 2007) and more than 1,000 MW/cycle about 284 times (up from 63 in 2007). The only change? Increased wind energy penetration.

 

On Page 69:  The ERCOT balancing of plants to accommodate wind energy produced results similar to the PSCO system; increased balancing resulted in significantly more SOX and NOX emissions than if wind energy had been absent. Any CO2 emission reductions were minimal at best, due to the significantly degraded heat rates of the balancing plants. 

 

Remedy for Wind Energy Balancing Problems of Colorado and Texas 

 

A way out for PSCO and ERCOT is to retire older coal plants that have efficiencies of about 30% and emit about 2.15 lb of CO2/kWh and replace them with utility-owned, gas-fired CCGTs that have efficiencies of up to 60% and emit about 0.67 lb of CO2/kWh. The CCGTs have short installation periods and capital costs of about 1,250/kW. 

 

If wind were entirely absent, this measure would reduce the most CO2/kWh at the least $/kWh and would produce power at the least $/kWh. 

 

If some of the new units were used for balancing to accommodate wind energy, their Btu, NOX and CO2 per kWh would increase, mostly offsetting the CO2/kWh reduction due to wind energy, as shown by this and other studies.

 

In addition their operation as balancers would shorten their useful service lives and incur additional owning and O&M costs, because their CFs would be about 0.70, instead of about 0.85 - 0.90 as base-loaded units, as shown by this study and other studies.

 

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

http://theenergycollective.com/willem-post/46977/impacts-variable-intermittent-power-grids

 

PUBLIC OPPOSITION TO WIND ENERGY

 

Example of Opposition to Transmission Corridors: The Northern Pass HVDC Transmission Line, capacity about 1,200 MW, is planned to be built from Windsor, Quebec, to Deerfield, New Hampshire. It would run partly in an existing right-of-way adjacent to an existing HVDC line in northern New Hampshire and would run for 16 miles via a new right-of-way through the White Mountain National Forest in New Hamshire. There would be about 1,000, highly visible towers, each 80 to 135 feet high, looming over the landscape. The estimated cost would be about $1.1 billion. 

 

Public opposition to this project has been fierce. Imagine what the opposition would be to $19 to $25 billion of new, highly visible transmission lines to accommodate wind and balancing energy to existing grids. See websites.

 

Renewables aficionados, legislators, renewables vendors, project developers and financiers and others clamoring for wind energy appear to have no idea regarding the costs and the impacts on the quality of life (noise, visual and psychological), property values and the environment due to reorganizing the New England electric grid towards accommodating wind energy and balancing energy in a major way.

 

Example of Opposition to Wind Turbines in Denmark: in Denmark the opposition has been building for some years. Dong Energy, the giant state-owned utility, finally announced in August, 2010, that it would abandon plans for new onshore wind turbine and that any future wind turbines would be offshore. 

 

Example of Opposition to Wind Turbines in the Netherlands: The Dutch government’s original plan was for 12,000 MW of wind turbine facilities; 8,000 MW offshore ($33.6 billion) and 4,000 MW onshore ($8 billion)) by 2020. 

 

Because of the high offshore costs, the plan was revised to 4,000 MW offshore ($16.8 billion) and 8,000 MW onshore ($16 Billion). If construction proceeds at the same rate as during the last few years, there will be a total of about 6,000 MW by 2020.

 

Expanding wind power to meet the European Union’s 20% renewables targets by 2020 means adding about 8,000 MW/3 MW = 2,667 wind turbines, 3 MW capacity, 466.5-ft tall, to the Dutch landscape at a cost of about $16 billion. The Dutch people may find that to be an unacceptable intrusion into their lives and an unacceptable return on their investment, especially when considering the small quantity of CO2 reduction per invested dollar. 

 

The Dutch government:

 

- decided in 2006 the Borssele nuclear plant would remain operational until 2033, a 60-year life, the same as dozens of similar plants in the US. 

- approved a plan to construct an up to 2,500 MW nuclear plant at Borssele which could consist of (2) Westinghouse AP1000 units @ 1,154 MW each. Final approval for construction may take several more years due to environmental and disturbance regulations and possible lawsuits by opponents.

 

http://www.nrel.gov/wind/systemsintegration/pdfs/2010/ewits_final_report.pdf

http://www.nrel.gov/wind/systemsintegration/pdfs/2010/wwsis_final_report.pdf

http://www.boston.com/news/local/massachusetts/articles/2010/12/17/study_wind_could_be_fourth_of_new_englands_power/ 

http://www.montrealgazette.com/business/Hampshire+blocks+Hydro+Québec+plan/4546549/story.html

http://peakoil.com/publicpolicy/transmission-lines-and-gop-politics-its-all-local-and-its-impenetrable-too/

http://www.livefreeorfry.org/

http://theenergycollective.com/willem-post/51642/dutch-renewables-about-face-towards-nuclear

 

SUBSIDIES FOR WIND FACILITY OWNERS

 

Over the past 10 years, the subsidies for wind turbine facility owners have become so excessive that facilities are built in marginal wind areas, as on most Vermont ridge lines, or before facilities are built to transmit the wind energy to population centers, as in the Texas Panhandle, just to cash in on the lucrative subsidies.  Here is a partial list of subsidies:  

 

- Federal grant for 30% of the total project cost which also applies to Spanish, Danish, German and Chinese wind turbines thus creating jobs in those nations instead of the US. 

 

- Federal accelerated depreciation allowing the entire project to be written off in five years which is particularly beneficial to wealthy, high-income people looking for additional tax shelters.

 

- Federal production credit of $0.022/kWh of wind energy produced. The justification provided by proponents: Wind energy is CO2-free whereas fossil energy is not. This study shows the EXTRA CO2 emitted due to the inefficient operation of the balancing facillity to accommodate wind energy to the grid (compared to the facility being base-loaded) is about equal to the CO2 the wind energy was meant to reduce. 

 

- Owners of wind turbine facilities receive Renewable Energy Certificates which they can sell on the open market. The RECs are subsequently bought by polluting companies that find it less expensive to buy the RECs than clean up their pollution.

 

- State legislatures are pressured to provide increasingly greater state incentives to politically well-connected renewables vendors, developers, financial entities and high-income future wind facility owners. See below.

 

- State legislatures and state government agencies are pressured to pave the regulatory ways to essentially circumvent state environmental and quality of life laws. Pro-forma hearings, usually required by law, are held to create a semblance of democratic process but effectively are rubber-stamp approvals of pre-ordained decisions.

 

INDEPENDENT POWER PRODUCERS AND POWER PURCHASE AGREEMENTS

 

The above politically well-connected people often become independent power producers, IPPs, that sell their wind energy to a state’s public utilities under long-term (usually 20 years) power purchase agreements, PPAs, often at favorable, state-subsidized, feed-in-tariff rates. 

 

The IPPs have greater profits, if they operate their plants steadily near rated output. They do not make their plants available for balancing, as it would reduce their output and profits. Accordingly, only utility-owned plants are available for balancing. Public utilities operate on a cost-plus basis; their justifiable costs due to balancing would be made up with rate increases in addition to regular rate increases, or a wind accommodation fee on wind turbine facility owners, or both. 

 

The IPPs of existing wind turbine facilities on the NEEG have PPAs with utilities. These IPPs have their facilities, capacity about 250 MW primarily in western Maine, in the best wind locations and have been getting a free ride as their wind energy impact on NEEG regulation and spinning plant operations is not yet “noticeable”, according to ISO-NE personnel. The main reason it is not noticeable is because of a lack of proper data measuring and recording. 

 

As NEEG wind energy penetration increases, the impact would be noticeable and stricter requirements regarding frequency regulation and variability of wind turbine facility outputs would be required, instead of placing the onus on ISO-NE, NEEG plants and ultimately rate payers. Compliance with such stricter requirements is being deployed in nations with higher wind penetration, such as Spain, Ireland, Germany, etc.  http://www.renewableenergyworld.com/rea/news/article/2010/10/how-spain-d....

 

WIND ENERGY ACCOMMODATION FEES 

 

Nationwide wind energy accommodation fees vary from about $2/MWh at low wind energy penetrations to $9/MWh at high wind energy penetrations. Currently, the Bonneville Power Authority charges about $5.7/MWh, or $0.0057/kWh, for balancing its hydro plants to accommodate wind energy. Hydro-Quebec likely would charge a similar fee. http://www.lawofrenewableenergy.com/2009/07/articles/bpa-issues-decision...

 

Currently, wind turbine facility owners are not paying any wind accommodation fees for the use of the spare balancing capacity in the NEEG system and for the additional fuel required to cycle the units, because at 0.5% wind energy penetration, it is not noticeable, according to ISO-NE personnel.  

 

Some extra owning and O&M costs due to adding wind energy to the NEEG are:

 

- expanded utility-owned balancing facilities which will have shorter useful service lifes and extra O&M costs due to balancing hundreds of times a day to accommodate wind energy versus only a few times a day without wind energy. 

- expanded overlay grid and T&D systems

- expanded weather prediction systems

- increased frequency regulation 

- increased ISO-NE management efforts 

 

The extra owning and O&M costs would be significant. What percentage of those costs should be charged as wind energy accommodation fees to wind turbine facility owners? 

 

MAKING WIND TURBINE FACILITIES MORE GRID FRIENDLY

 

Grid operators in states such as Colorado and Texas find that increased expansion of wind turbine facilities by IPPs makes it more and more difficult to accommodate wind energy to the grid, especially during large changes in wind speeds. See summary of Bentek study below. 

 

Owners of wind turbine facilities should be required to:

 

- install their own balancing facilities to provide balancing energy BEFORE the wind energy enters the grid.  

 

- design their wind turbine facilities so they present less variable output to the grid, such as by automatically feathering their rotor blades to limit minute-by-minute ramp rates of their output. This can be accomplished at minor reductions of production and at minor additions to capital costs. 

 

Note: Ireland enacted a new grid code in 2004 that requires wind turbine facilities to reduce the variability of their outputs, i.e., be grid-friendly. See Page 17 of http://www.ref.org.uk/attachments/article/171/david.white.wind.co2.savin...

 

COLLECTING POWER PLANT AND GRID OPERATING DATA

 

ISO-NE would be well advised to set up centralized data logging at 10  to 15 minute intervals of: 

 

- electrical energy fed into and taken from the NEEG by all wind turbine facilities.

- fuel consumption and CO2 emissions of all plants on the NEEG. 

Note: many NEEG plants already report hour-to-hour emissions of NOX, SOX and particulate to the US-EPA.

 

Such data is essential for any accurate analysis and comparison of power generation alternatives to reduce CO2 emissions; flying blind regarding global warming is inexcusable and likely wasteful. The Electric Reliability Council of Texas, ERCOT, collects such data at 15-minute intervals.

 

Note: IPPs are opposed to collecting such data. They are also opposed to releasing any operating data of their wind facilities under the guise of "trade secrets". Anything subsidized with public funds should have "full disclosure" to enable the public to evaluate if their money is wisely spent.