Wind power is interesting because it is available even when solar collectors aren't working, but wind tends to be highly variable. Our electrical grid is designed around power plants that are slow to change the amount of energy they provide. For best effectiveness, wind power ought to be stored on site (in batteries or capacitors?) and delivered to the grid in a predictable manner - however, that adds to the cost and isn't being done at this time (except in Japan).
Loss of wind causes Texas power grid emergency U.S. Reuters:
"HOUSTON (Reuters) - A drop in wind generation late on Tuesday, coupled with colder weather, triggered an electric emergency that caused the Texas grid operator to cut service to some large customers, the grid agency said on Wednesday.
Electric Reliability Council of Texas (ERCOT) said a decline in wind energy production in west Texas occurred at the same time evening electric demand was building as colder temperatures moved into the state.
The grid operator went directly to the second stage of an emergency plan at 6:41 PM CST (0041 GMT), ERCOT said in a statement.
System operators curtailed power to interruptible customers to shave 1,100 megawatts of demand within 10 minutes, ERCOT said. Interruptible customers are generally large industrial customers who are paid to reduce power use when emergencies occur.
No other customers lost power during the emergency, ERCOT said. Interruptible customers were restored in about 90 minutes and the emergency was over in three hours."
Surge in wind power causes spike in NW power grid Local News kgw.com News for Oregon and SW Washington:
"PORTLAND, Ore. -- The wind huffed, and it puffed, and it nearly caused major problems in the Northwest's electrical grid last week.
Power managers say they have some fixing to do.
A surge of wind last Monday afternoon jumped far beyond levels forecast by operators of Oregon's burgeoning wind-farm industry, sending more power into the regional grid than it could handle.
The Bonneville Power Administration is responsible for adjusting hydropower generation levels to accommodate the power from wind turbines so the system isn't overloaded.
It realized by Monday evening that it could no longer handle the surge without increasing spills of water through hydroelectric dams to levels dangerous to fish. Spilling the water keeps it from the hydropower generators.
. . .
So, for the first time, BPA power managers began calling wind-farm operators with orders to curtail power generation.
But calls to some wind farms reached only answering machines, and at another the operators misunderstood and kept generation steady. One wind-farm, which BPA wouldn't name, did reduce generation.
As it turned out, water the BPA had to spill wasn't heavy enough to do damage.
But a BPA official said it demonstrated a need to make sure that the growth of wind power in the Columbia Basin doesn't cause more such problems."
Oregon power council releases wind energy plan Daily Journal of Commerce (Portland, OR) Find Articles at BNET:
"Electrical utilities may have a lot of power, but they can't force the wind to blow.
And as Northwest states increasingly develop wind power projects and pass mandates for renewable resources, regional power suppliers must determine how to provide constant electricity from wind turbines at a minimal cost to customers.
'Wind is an intermittent resource and tends not to blow on the hottest and coldest days, which tend to be the days of peak load,' Steve Wright, administrator of the Bonneville Power Administration, said. 'Fundamentally the question here is, 'How do you make wind resources work in a system in which consumers demand high reliability?''
A new wind integration plan, released yesterday by the Northwest Power and Conservation Council, has taken the first step in solving the region's wind power problems.
The plan does not, however, evaluate the consequences of implementing Oregon's proposed renewable portfolio standard (RPS), under review by the Oregon Senate, which would require utilities to obtain 25 percent of their new energy production from renewable resources by 2025.
. . .
Spreading wind farms throughout different geographic regions, building additional transmission lines, and coordinating transmission scheduling and new resource development among regional electrical utilities will be the key steps to integrating additional wind resources, according to the plan.
Because electricity cannot be stored and must be used when it is produced, the plan also calls for a number of backup measures to offset periods when the wind isn't blowing.
The region's hydropower system currently acts as a fallback for wind projects already up and running. Power can be "stored" by retaining water behind dams along the Columbia River while the wind is blowing, and released to spin the hydro facilities' turbines on still days.
But the hydro system is nearing its production capacity due to increased regional demand for power and tougher fish and wildlife regulations that limit power production in an effort to better protect the river's wild salmon.
The plan "is timely- We've got a hydro system that is increasingly being constrained," Tim Culbertson, general manager of the Grant County public utility district, said. "Planning for it now is going to give us many better options on how to plan for that as a resource that can be counted on in the region.""
Japan's wind-power problem [National Wind Watch]:
". . .
Wind farms make their money by selling energy contracts to electric companies. When the regional utilities don’t agree to buy the full amount of the electricity they generate, developers are left in a bind.
But utilities don’t view wind as the perfect power. After all, the electricity that wind-power projects supply fluctuates depending on the wind’s strength, setting up a risk for power surges and outages. To neutralize this problem, utility companies have asked developers to store the energy created from wind power in batteries that can be tapped when needed, rather than to channel the energy directly to the grid.
In an effort to appease utilities, wind developers have begun to do just that. Japan Wind Development Co. and battery maker NGK Insulators have partnered to install battery accumulators at a wind-power site in the Aomori Prefecture this year (see Batteries for the Grid). NGK’s sodium-sulfur batteries store energy created when the wind blows and dispatch the smooth energy to the grid during peak demand periods.
Still, batteries are not ready for wide-scale adoption, mainly because of their price. They can double the cost of a project, and it is unlikely project developers will be able to pass these costs to the utilities.
Off-shore wind developments are another attractive, and possibly less costly, option.
It is both more powerful and more predictable than land-based wind power, two factors that may help allay utility concerns about power surges and capacity, and also can be located closer to main city centers, where the electricity is used. Most wind farms in Japan today are located in the far north or south, where land is cheaper and less inhabited, and none are near Tokyo.
European countries have been looking to the sea for years. Japan too has experimented. Two turbines have been in operation in the northern island of Hokkaido – less than 1 kilometer off the coast – since 2003, and the University of Tokyo and Tokyo Electric are investigating the possibility of an off-shore wind farm near Tokyo.
But Japan’s geography complicates such projects. The country is surrounded by deep water, and deep-water wind-farm technology is still in its infancy. Last year, Scotland installed two 87-meter-high wind turbines 25 kilometers off its coast. The installation is the biggest project of its kind in the world and still in the trial stages.
Mr. Iida said similar plans for Japan may be years off if they happen at all. Aside from the expense (off-shore wind farms can cost two to three times onshore projects), it must contend with opposition from the politically powerful fishing industry"
A Problem With Wind Power [AWEO.org]:
"In 1998, Norway commissioned a study of wind power in Denmark and concluded that it has 'serious environmental effects, insufficient production, and high production costs.'
Denmark (population 5.3 million) has over 6,000 turbines that produced electricity equal to 19% of what the country used in 2002. Yet no conventional power plant has been shut down. Because of the intermittency and variability of the wind, conventional power plants must be kept running at full capacity to meet the actual demand for electricity. Most cannot simply be turned on and off as the wind dies and rises, and the quick ramping up and down of those that can be would actually increase their output of pollution and carbon dioxide (the primary 'greenhouse' gas). So when the wind is blowing just right for the turbines, the power they generate is usually a surplus and sold to other countries at an extremely discounted price, or the turbines are simply shut off.
A writer in The Utilities Journal (David J. White, 'Danish Wind: Too Good To Be True?,' July 2004) found that 84% of western Denmark's wind-generated electricity was exported (at a revenue loss) in 2003, i.e., Denmark's glut of wind towers provided only 3.3% of the nation's electricity. According to The Wall Street Journal Europe, the Copenhagen newspaper Politiken reported that wind actually met only 1.7% of Denmark's total demand in 1999. (Besides the amount exported, this low figure may also reflect the actual net contribution. The large amount of electricity used by the turbines themselves is typically not accounted for in the usually cited output figures.
. . .
The head of Xcel Energy in the U.S., Wayne Brunetti, has said, "We're a big supporter of wind, but at the time when customers have the greatest needs, it's typically not available." Throughout Europe, wind turbines produced on average less than 20% of their theoretical (or rated) capacity. Yet both the British and the American Wind Energy Associations (BWEA and AWEA) plan for 30%. The figure in Denmark was 16.8% in 2002 and 19% in 2003 (in February 2003, the output of the more than 6,000 turbines in Denmark was 0!). On-shore turbines in the U.K. produced at 24.1% of their capacity in 2003. The average in Germany for 1998-2003 was 14.7%. In the U.S., usable output (representing wind power's contribution to consumption, according to the Energy Information Agency) in 2002 was 12.7% of capacity (using the average between the AWEA's figures for installed capacity at the end of 2001 and 2002). In California, the average is 20%. The Searsburg plant in Vermont averages 21%, declining every year. This percentage is called the load factor or capacity factor. The rated generating capacity only occurs during 100% ideal conditions, typically a sustained wind speed over 30 mph. As the wind slows, electricity output falls off exponentially.
In high winds, ironically, the turbines must be stopped because they are easily damaged. Build-up of dead bugs has been shown to halve the maximum power generated by a wind turbine, reducing the average power generated by 25% and more. Build-up of salt on off-shore turbine blades similarly has been shown to reduce the power generated by 20%-30%.
. . .
Despite their being cited as the shining example of what can be accomplished with wind power, the Danish government has cancelled plans for three offshore wind farms planned for 2008 and has scheduled the withdrawal of subsidies from existing sites. Development of onshore wind plants in Denmark has effectively stopped. Because Danish companies dominate the wind industry, however, the government is under pressure to continue their support. Spain began withdrawing subsidies in 2002. Germany reduced the tax breaks to wind power, and domestic construction drastically slowed in 2004. Switzerland also is cutting subsidies as too expensive for the lack of significant benefit. The Netherlands decommissioned 90 turbines in 2004. Many Japanese utilities severely limit the amount of wind-generated power they buy, because of the instability they cause. For the same reason, Ireland in December 2003 halted all new wind-power connections to the national grid. In early 2005, they were considering ending state support. In 2005, Spanish utilities began refusing new wind power connections. In 2006, the Spanish government ended -- by emergency decree -- its subsidies and price supports for big wind. In 2004, Australia reduced the level of renewable energy that utilities are required to buy, dramatically slowing wind-project applications. On August 31, 2004, Bloomberg News reported that "the unstable flow of wind power in their networks" has forced German utilities to buy more expensive energy, requiring them to raise prices for the consumer.
. . .
In the U.K. (population 60 million), 1,010 wind turbines produced 0.1% of their electricity in 2002, according to the Department of Trade and Industry. The government hopes to increase the use of renewables to 10.4% by 2010 and 20.4% by 2020, requiring many tens of thousands more towers. As demand will have grown, however, even more turbines will be required. In California (population 35 million), according to the state energy commission, 14,000 turbines (about 1,800 MW capacity) produced half of one percent of their electricity in 2000. Extrapolating this record to the U.S. as a whole, and without accounting for an increase in energy demand, well over 100,000 1.5-MW wind towers (costing $150-300 billion) would be necessary to meet the DOE's goal of a mere 5% of the country's electricity from wind by 2010."
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