“Power plants, usually natural gas, must be kept in spinning reserve, ready to come online when the wind stops blowing or the sun stops shining. There is the cost of natural gas to keep these units operating off-line, as well as maintenance costs from the added wear and tear on these units.”
“The strongest winds, which are the best for generating electricity, are found hundreds, if not a thousand or more miles away from where the electricity is used. [Fossil-fuel] power plants are located closer to where the electricity is used.”
“Coal-fired and NGCC power plants were built to operate as baseload plants operating continuously. Cycling results in an increase in the number of cold-starts and shutdowns.”
The renewable-energy lobby has the advantage of many citizens having short attention spans and not being experts in the field. Thus the notion of a free energy input (wind) seems appealing–clean and green and cheap.
But this impression is opposite from the truth in many ways. Cost-wise, it is fallacious.
Aside from the fact that the levelized cost of electricity (LCOE) is higher for wind and solar, there are many other operating costs that result in wind and solar being far more expensive than coal or natural gas for generating electricity.
Back-up
This is a well-documented cost, where power plants, usually natural gas, must be kept in spinning reserve, ready to come online when the wind stops blowing or the sun stops shining. Wind and solar are unreliable, and must have back-up power ready to go on-line at a moment’s notice. First, there is the cost of natural gas to keep these units operating off-line, but secondly, there are the additional maintenance costs from the added wear and tear on these units.
Storage
Storage is required to minimize the effect of rapid ramping up of fossil fuel power plants when the sun sets, or as an alternative to keeping natural gas power plants in spinning reserve. The CAISO Duck curve illustrates what happens when the sun sets, and fossil fuel power plants must be rapidly brought on-line to meet demand. Storage could theoretically provide some of the power needed when the sun sets.
The cost of storage varies, but at a minimum is around $2,000 per KW, about the same as the cost of a new natural gas combined cycle power plant. A recent trial by Pacific Gas & Electric resulted in storage costs that were more than twice as large.
The CAISO Duck Curve illustrates the sudden ramping as renewables increase.
Transmission Lines
The strongest winds, which are the best for generating electricity, are found hundreds, if not a thousand or more miles away from where the electricity is used. This requires building expensive transmission lines. While it’s true, new coal-fired or natural gas combined cycle (NGCC) power plants may also need new transmission lines, these power plants are located closer to where the electricity is used.
The Joint Coordinated System Plan determined it would cost an additional $200 billion to build the transmission lines needed if only half the nation used wind energy, where wind supplied only 20% of the power.
More recent is the Pathfinder wind energy project that requires a $3 billion investment in transmission lines (see, Absurd Cost of California Wind).
Cycling
Coal-fired and NGCC power plants were built to operate as baseload plants operating continuously.
Because wind and solar operate intermittently, it’s necessary for these baseload plants to cycle up and down, following the constantly changing output from wind and solar plants. Cycling also results in an increase in the number of cold-starts and shutdowns.
Cycling puts an added strain on boilers, turbines and many other components of the transmission and distribution system. Thermal expansion and contraction is the main culprit. Different materials have different coefficients of expansion, so boiler tubing may expand more rapidly than the firewalls and other materials surrounding the tubing.
Ramping up when the sun sets, as described above, also causes this type of damage.
This damage increases maintenance costs. Utilities, such as Duke Power, are installing new monitoring equipment and attempting to develop new operating methods in an effort to minimize the damaging effects of transient temperatures.
Industry trade publications, such as Power Magazine and Turbomachinery International, are recognizing the damaging and costly effects of cycling.
Summary
All of these are operating costs that are borne by the utility and eventually paid for by customers.
They don’t include the social costs when there is a blackout, such as occurred in South Australia due to the unreliability of wind and solar. And not included is the environmental problem of energy sprawl from dilute in place of dense energy, explained elsewhere.
Just this morning, those unbiased, crack investigative “journalists” at National Public Radio provided an open microphone and broadcast platform for Michael R. Bloomberg and Carl Pope (late of the Sierra Club) to make their preposterous claim that renewable energy is now “less expensive than other sources.** ”
** where the wind blows and the sun shines.
_________________________
Why is it that we taxpayers are forced to fund that completely bent propaganda outlet ?
Mr. Dears gets the right general idea across. What he gets wrong is (1) wind requiring backup; (2) problematic wind intermittence; (3) wind requiring new transmission systems much like those for new coal or natural gas plants; (4) his assumption (a la the folly of the PG&E “experiment”) about the physical viability of grid-level “storage” as a substitute for the inefficient ramping of wind following conventional generation (he focuses on the economic costs, alas).
1. The idea that wind requires backup is a howler. Backup literally means a reserve or substitute for the real thing, often in the form of an understudy or a computer file. Or it can mean support for a much larger object or activity. In the first case, the backup is sufficiently like the original (what is backed up) that performance should not be markedly corrupted. A second-string quarterback should in virtually all-important respects be able to do what the first- string quarterback does. Ditto for an understudy forced into mainline service because of illness to the diva. In the second case, a backup buttress to an architectural feature plays a small role in the scheme of things, nice for security to be sure, but nonetheless, it is a minor part of the whole. Although it is a proactive measure in terms of ultimate security, it is mainly reactive in function. Given the erratic, skittering nature of its delivery, wind cannot merely be “backed up” by a slightly corrupted version of itself. Quite the contrary. It is as if wind is the whacky substitute requiring the first team, the diva, to make it functional. In the best Orwellian newspeak fashion, it is the backup that does virtually all the important work—but in a much more inefficient fashion. How would the world’s best actor squelch, live onstage, a drunken understudy who continually spoke lines from another play?
Wind machines must always be ENTANGLED with proactive but inefficiently operating conventional machines throughout the entire extent of any wind machine’s full capacity.
2. Wind’s overarching problem is its continuous output volatility as a function of the cube of the wind speed along a narrow wind speed range. Not its intermittence. ALL ELECTRICITY GENERATORS ARE TO SOME EXTENT INTERMITTENT. But they are not existentially so, as is the case with wind. Should the intentional highly predictable intermittence of an open cycle gas generator, with an annual capacity factor of 5 percent, be fairly compared with a wind generator’s unpredictable flutter, even as it produces, say, a 25% capacity factor?! AWEA would have us think so.
3. As is the case in Texas, with its expansive transmission system built to “integrate” remote wind energy, transmission systems for wind are virtually dedicated lines. They are not generally shared with conventional generation sources. This is so to avoid massive scheduling problems that must occur with a lot of desultory wind output.
4. The physical reality of storage to enable grid level wind by smoothing out its flux (but not its intermittence) is always right around the corner. Edison spent a fortune trying to achieve it. And failed. All the king’s chemicals, all the king’s mechanical gadgetry, all the king’s water resources, and all the king’s empty rhetoric will never be able to put the Humpty of wind output together again as a capacity resource. EVEN IF THE KING COULD, what a truly stupid thing to do. Something this valuable should be placed in service of conserving capacity fuels, not promoting wind flutter.
Trying to put a price on a non-existent phenomenon, even if that price seems forbiddingly high, is both penny unwise and pound ridiculous. Those pushing the idea should be ridiculed, then tasked to provide testable proof of the reality of the scheme.
[…] another good article from Master Resource—explaining why renewables cost […]