Haphazardly dropped into the middle of an interesting and otherwise technically accurate New York Times article about a new type of solar power plant are a couple of paragraphs of unsubstantiated nonsense on the topic of wind energy integration. The only source for the “information” in these paragraphs appears to have been an interview with Lester Lave, a wind opponent who is well-known among wind power integration experts for making technically specious claims on the topic.
To refute his misleading or outright incorrect claims point-by-point:
1. "’As long as the contribution of wind and solar is very small, utilities can handle it very well,’ Mr. Lave said. But what happens once the share of renewable power rises to 10 percent? Or 20 percent? ‘No one knows what the magic number is.’"
That statement would certainly come as a surprise to utility system operators in Germany, Spain, Denmark, Portugal, or Ireland, or for that matter any of a number of regions of the U.S., all of which have successfully integrated wind farm penetrations of around 10% up to 20% and beyond. Ireland, for example, is at approximately 10% wind penetration, and its government recently completed a study concluding that there are no major technical barriers to reaching 40% wind turbines penetration. That is especially noteworthy because integrating wind energy onto the grid is more challenging on a small island than it is on a large interconnected power system like we have in the U.S. Denmark currently stands well over the 20% wind mark and is working to increase that amount several times over. At the very moment that I am writing this (the evening of March 4), wind is providing over 20% of the electricity being used in Texas. In these places there may be some costs to operating the power system differently than it would have been operated without a large amount of wind, but any wind integration expert would laugh at that the idea that there is a “magic number” ceiling on the amount of wind that can be integrated with the power system.
2. "Spain, which generates more than 12 percent of its electricity from wind, has struggled with wind variability, Mr. Lave said."
This statement would also come as a surprise to grid operators in Spain. Among wind integration experts, Spain is widely regarded as a success story and as a pioneer in developing advanced wind forecasting and other techniques that have made it possible to incorporate a large amount of wind energy at low cost. In fact, wind has provided more than 40% of Spain’s electricity on several occasions and in one instance 53% of the nation’s power without any problems. Some substantiation for the claim that Spain has “struggled with wind variability” would have been helpful, because most wind integration experts would be at a loss if forced to guess what Mr. Lave is referring to with that statement.
3. "Because electricity cannot be stored easily, utilities must always produce enough power to meet electric demand at any given time. In practice, this means they need keep a lot of idle plants that can be fired up rapidly when demand spikes."
The article misleadingly implies that these power plants must be kept around for the sole purpose of accommodating the variability of wind energy and other renewable resources, when in reality the power system has always operated with a significant margin of plants that can be called up when electricity demand increases. Electricity demand varies by a factor of three or more depending on the time of day and year, so at any point in time the odds are that less than half of a utility’s generation capacity is being utilized, whether it has wind on its system or not. In addition, recent wind integration studies like one released by the National Renewable Energy Laboratory in January have found that adding diversely located wind energy resources to the power system can significantly reduce the quantity of power plants that must be maintained for capacity adequacy reasons.
4. "In 2008, for example, Texas narrowly avoided a blackout when wind power, which supplied 5 percent of demand at the time, experienced an unexpected lull…"
No wind-bashing article would be complete without reciting the oft-repeated and even more oft-debunked myth about wind supposedly causing an emergency situation on Texas’s power grid two years ago. In reality, the generation shortfall that day was almost entirely caused by a combination of (1) electricity demand increasing by 1,185 MW more than expected over a single hour and (2) conventional generators falling below their scheduled output. By comparison, wind output gradually declined over the course of four hours, a change that would now be easily predicted at least a day in advance by the wind forecasting program the Texas grid operator has now implemented. Moreover, the events of that day were hardly a near-blackout as Lave claims; generation shortfalls of an even larger magnitude occur several times per year on average, almost always when a large nuclear or coal plant experiences an unexpected outage and takes 1,000 MW or more of generation offline instantaneously. For a more detailed discussion of what really happened that day, please see:
http://www.awea.org/newsroom/pdf/AWEA_Viewpoint_on_ERCOT_event_031208.pdf
