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Comment by Willem Post on October 29, 2013 at 10:07pm

NREL WIND ENERGY VISION

The US-DOE is envisioning the US having at least 20% of its energy from IWTs by 2050. Most of the wind turbines would be located in the Great Plains, where are the good to excellent winds. Currently, about 90% of wind turbine capacity, generating at least 95% of wind energy, is located west of Chicago.
 
The National Renewable Energy Laboratories, NRELs, have proposed multiple corridors with High Voltage Direct Current, HVDC, lines from the Great Plains to the East Coast, where the people are. Those lines have much less line losses than HVDC  lines, and can be buried, or on pylons, as needed, to satisfy NIMBY concerns.
 
The implementation of at least 20% wind energy would have major impacts on the US electric power system and would require trillions of dollars.

Wind Energy Production and Transmission: About 90% of all wind turbines are west of Chicago. Transmitting their energy from the Great Plains to the East Coast via the envisioned seven (7) HVDC lines incurs energy losses.

Energy has to be gathered from wind turbines and brought to a substations to raise its AC voltage to the AC transmission level, then it is transmitted to other substations to raise the voltage to that of the HVDC line, then the AC is converted to DC, then the DC is sent to the East Coast via the east-west HVDC lines, then to the north-south HVDC trunk lines, then the DC is converted to AC, then the voltage is stepped down to the AC transmission level, then via substations to the distribution systems.
 
The AC/DC units and transformers will see loads from 0% (wind-still days) to up to 90-100% (strong wind days) with an annual average of about 30% (the capacity factor), i.e., at part-load the efficiency of the AC/DC units and transformers is significantly decreased.
 
This means multiple AC/DC units and transformers at each end of the HVDC lines to minimize losses.
 
This also means the entire system has to be designed for 100% of the wind turbine capacity, but will be utilized at an annual average of only 30%, much less than the normal 60% for transmission systems.

Below is a list of assumptions to estimate the overall loss. 

Average capacity factor, CF, of all wind turbines west of Chicago = 0.38
Loss due to gathering wind energy to AC lines = 1%
Loss due to step up to Great Plains AC voltage = 1%
Loss due to AC transmission to HVDC lines = 2%
Loss due to step up to HVDC voltage = 1%
Loss due to AC to DC, 2000-mile HVDC transmission, DC to AC = 14%*
Loss due to step down to East Coast AC voltage = 1%
Loss due to transmission on East Coast = 3%
Loss due to distribution to users = 4%
Total losses = 27%
* See David JC MacKay’s book “Sustainable Energy; without the hot air”, pg. 179

As a result of the above losses, the average CF of 0.38 at the wind turbine is reduced to about 0.28 at the user’s meter, for a 27% loss!!

There are additional energy and wear-and-tear losses to accommodate wind energy to the grid:

- increased plant capacity and increased hours of part-load-ramping operation to balance the variable wind energy. 
- increased plant capacity and increased hours of 3,600 rpm spinning operations, which requires about 8% of the fuel consumption at rated output, to instantly provide energy when significant wind energy ebbing occurs. 
- increased plant capacity and increased frequency of plant start/stop operations, to provide energy when significant wind energy ebbs or surges are predicted to occur.
http://theenergycollective.com/willem-post/89476/wind-energy-co2-em...
 
Wind Turbine Replacement Scenario: As the above NREL-envisioned IWT build-out proceeds to achieve 20% wind energy by 2052, and assuming a 20-year life, almost all of the existing 52,000 MW of IWTs would need to be refurbished or replaced during 2012 - 2032, if economically/technically viable, plus the new IWTs built during 2012 - 2032 would need to be refurbished or replaced during 2032 - 2052, etc.

Wind Turbine Capacity: Assuming a life of 20 years, onshore capacity factor of 0.30 and offshore of 0.38, energy production growth at 0.9%/yr (due to electric vehicles?), a spreadsheet-based analysis shows, it would take about 425,000 MW of IWTs, onshore and offshore, to provide about 1,170 TWh in 2052, about 20% of the total US production in that year.

Wind Turbine O & M Costs: Below URLs show 2011 estimates of US wind turbine O & M varying by region: about $26,000/MW in Texas and Southwest; about $30,000 - $32,000 in the Great Plains and Midwest; about $40,000/MW in Pennsylvania, New York, Maine, etc. Offshore would be about $50,000 - 60,000/MW.

These US costs have been steadily rising from an average of about $22,000/MW in 2008 to an average of about $31,000/MW in 2011, despite claims they would be declining by wind energy proponents.

Note: For proper comparison, O & M cost should include variable costs, such as labor, parts, crane rental, consumables, etc., plus fixed costs, such as insurance, administation, etc.

Note: Other major O & M costs result from increased spinning, start/stop, balancing and grid operations due to wind energy being on the grid.

https://www.wind-watch.org/news/2013/03/08/rising-wind-farm-om-costs/ 
http://www.windpowerengineering.com/maintenance/report-om-costs-hea...
http://nawindpower.com/digitaleditions/Main.php?MagID=2&MagNo=3...
http://www.nrel.gov/docs/fy08osti/40581.pdf

Grid Level Costs: As RE build-outs take place, more becomes known regarding grid level costs. The below OECD study quantified the levelized costs of the grid level effects of variable energy, such as wind and solar, on the grid. It includes the costs of wind energy balancing, PLUS the costs of grid connection, reinforcement and extension, PLUS the costs of back-up (adequacy), i.e., keeping almost all EXISTING generators fueled, staffed, and in good working order to provide energy when wind energy is minimal, about 30% of the hours of the year in NE, about 10-15% of the hours of the year west of Chicago.

In the US, the costs of the 3 PLUSSES for onshore IWTs are minimal when the annual wind energy on the grid is only a few percent, because most grids have some spare capacity to absorb variable wind energy. As the wind energy percentage nears 3 - 5%, the spare capacity is used up and the costs of the 3 PLUSSES are about $7.5/MWh at 5%, about $16.30/MWh at 10%, and about 19.84/MWh at 30%. This is significantly greater than the about $5/MWh usually mentioned by IWT promoters. See page 8 of below URL. Corresponding costs for offshore wind turbine plants would be significantly greater.

These costs are a significant part of the US annual average grid price of about 5 c/kWh. Mostly, they are "socialized", i.e., charged to rate payers, not to wind turbine owners. As a result, wind turbine owners, with help of other subsidies, such as the 2.3 c/kWh production tax credit, can underbid other low-cost producers, causing them to sell less energy and become less viable over time, i.e., future investors would be less willing to invest in such producers, unless compensated with "capacity payments", that also will be charged to rate payers, not wind turbine owners.

http://www.oecd-nea.org/ndd/reports/2012/system-effects-exec-sum.pdf
http://en.wikipedia.org/wiki/Cost_of_electricity_by_source 

The 40-year cost for new, refurbished and replaced IWTs, back-up (adequacy), balancing, grid connection, grid reinforcement and extension would be about $2 TRILLION, unsubsidized, with further annual capital costs after 2052 to maintain the 425,000 MW of IWTs as an on-going energy producer. 

Economic Impact of NREL Build-out: The increased capital cost of IWT build-outs, refurbishments/replacements, balancing plants and grid reorganization, and the impact of the lesser CFs and shorter lives would greatly increase the US levelized cost of energy.

If US wind energy goals were increased to 30% or even 40%, levelized costs, and various other adverse impacts, would be proportionately greater.

Unless developing nations, i.e., China, India, Brazil, etc., handicap themselves in a similar manner (which appears unlikely, based on the outcome of COP-18 in Dohu, Qatar, in 2012), the US, with a low-growth economy and huge trade and budget deficits, would be at an even relative greater economic disadvantage than at present.

Add to that situation wind energy not being anywhere nearly as effective regarding CO2 emission reduction as increased energy efficiency, one may wonder if the Western World is on the right course regarding CO2 emission reduction.

http://theenergycollective.com/willem-post/151031/global-warming-ta...
http://theenergycollective.com/willem-post/71771/energy-efficiency-...
http://theenergycollective.com/willem-post/46652/reducing-energy-us... 
http://theenergycollective.com/willem-post/89476/wind-energy-co2-em...