Wind power is clean, renewable, and mechanically reliable, but it is not consistent. Obviously, wind does not blow all the time. Data from installed wind farms shows that wind is more likely to blow hardest when it is least needed. Often it does not generate any power for several days in a row. You can see this for yourself in this January 2009 chart from the Bonneville Power Administration (BPA) showing the wind power under their balancing authority.
This BPA graph shows an 13 day period in 2009 when wind generation remained essentially zero during a protracted spell of cold weather and high electrical demand. This is an example of why you can not eliminate any of your existing generating capacity with the construction of wind generators because you can’t count on the wind to blow when you most need the power!
We captured the following BPA graph was on August 19, 2013 at 11:00 AM. It shows the total electrical Load and totals for Wind, Hydro, and Thermal Generation included in the BPA’s Balancing Authority. You can derive an idea of the time of day from the darker vertical grid lines which denote midnight.
The total generation is always greater than the total Load because most of the time BPA is a net exporter of energy. The BPA Load does not include scheduled energy sent to other balancing authority areas. If you want to view the last seven days of power & load data (updated every five minutes), click here. This link also has a list of power plants included in the data graphed above.
The total electrical Load is displayed in red, the second line down. It has a predictable daily cycle of a late afternoon high followed by an after midnight low. Hydro generation is shown by the top blue line and Thermal (which includes coal, gas, nuclear, and wood waste burning) is indicated by the brown third line. The bottom green line is Wind. As you can see Wind usually peaks at night when it is least needed, and often doesn’t generate at all. There is no line for total generation (the sum for the blue, brown and green lines) as it would be off the chart. As the BPA notes, the generation capacity of their balancing authority exceeds their power demand and the excess energy is exported to other balancing authorities.
Notice that dispatchable (power industry jargon for being able to be turned on or off when needed) power sources like Hydro and Thermal have adjusted to follow the change in customers’ electrical demands. Wind, on the other hand, can not. Wind generates energy when it wants to, not when the customers need it. At least solar power peaks at midday, near to the time of greatest customer demand.
There is other information that can be deduced from this graph. The vertical scale is in megawatts (MW). The lowest line labeled 1000, represents approximately the electrical output of Bonneville Dam or one large coal or nuclear plant. So the variation in the Wind energy line represents the equivalent of adding or dropping three power plants worth of energy in an hours time. This large and rapid change in Wind power is hard for utilities to deal with. We are lucky in the Northwest as Hydroelectric power can be adjusted quickly. But Renewable Energies like Wind and Solar were legislatively mandated to reduce our dependence on fossil fuels and not to have us cut back on nonpolluting Hydro power. Notice that on Saturday, the Wind power averaged about 2000 MW. This could have been offset by shutting down some of the coal and natural gas energy included in the Thermal power’s 5,000 MW total. Instead the Thermal power line only drops slightly and carbon emission free Hydro power is cut back.
Legislation mandating the addition of 15 percent of Renewal Power to utilities energy portfolios was silly in a region where 75% of our power already comes from renewable Hydroelectric generation. Dealing with the variability of Wind power has only added to the overhead of agencies like the BPA and the money spent on windmills would have been better spent developing some clean sources of reliable, dispatchable power.
Web searching for wind power critics, we located a December 2012 report by George Taylor and Tom Tanton from the American Tradition Institute (ATI) called The Hidden Costs of Wind Electricity. This report asserts that the cost of wind power is significantly understated by the Federal Energy Information Administration’s (EIA) numbers. In fact, says Taylor, generating electricity from wind costs triple what it does from natural gas.
What the report shows, is that the EIA and the wind industry cost calculations do not include the costs of having some other generating source available to fill in when the wind doesn’t blow.
The link below is to ATI’s 36-page PDF report. If you do not have time to peruse all 36 pages, you can get to the core of the report by reading the four page Executive Summary (ES1 – ES4) PDF pages 4 – 7. Additionally, on page 24, the report discusses the Capacity Values of various energy sources (the percentage of your peak electrical demand that an energy source can be counted on to provide) adopted by Regional System Operators. The report notes that our own System Operator, the Bonneville Power Administration, adopted a value of zero for wind power after experiencing the 13-day period in 2009, (shown in the first graph above) when wind generation remained essentially zero during period of cold weather and high demand. In short, you can not eliminate any of your existing generating capacity with the construction of wind generators because you can’t count on the wind to blow when you most need the power!
Link to ATI’s Hidden Cost of Wind Electricity Report.
Its been noted that the American Tradition Institute has in the past railed against climate scientists and sought to discredit Global Warming. That doesn’t mean that their report’s calculations are wrong, just that everyone on the pro-wind side ought to read the report and chime in with their critiques. The wind industry did respond, but their responses seem to avoid directly challenging the report’s calculations of the real cost of wind power. Our view is that the report’s calculations are right on.
Batteries Won’t Save Wind Power
As the intermittency of wind become gains traction as a serious drawback to wind energy, wind proponents respond by saying that batteries would be a cost effective way to store energy during windless times. This argument has been debunked by a recent Stanford University study. Their study says that batteries may be a cost effective method of energy storage for solar farms but not for wind power. Until there are more cost-effective batteries or other energy storage devices, the leveling energy is best supplied by water stored behind a dam. “We looked at batteries and other promising technologies for storing solar and wind energy on the electrical grid,” said Charles Barnhart, the lead author of the study and a postdoctoral scholar at Stanford’s Global Climate and Energy Project (GCEP). “Our primary goal was to calculate their overall energetic cost – that is, the total amount of fuel and electricity required to build and operate these storage technologies. We found that when you factor in the energetic costs, grid-scale batteries make sense for storing surplus solar energy, but not for wind.” “Pumped hydro is used in 99 percent of grid storage today,” Barnhart said. “It works fantastically from an energetic perspective for both wind and solar. Its energy return on investment is 10 times better than conventional batteries.”
“We looked at batteries and other promising technologies for storing solar and wind energy on the electrical grid,” said Charles Barnhart, the lead author of the study and a postdoctoral scholar at Stanford’s Global Climate and Energy Project (GCEP).
“Our primary goal was to calculate their overall energetic cost – that is, the total amount of fuel and electricity required to build and operate these storage technologies. We found that when you factor in the energetic costs, grid-scale batteries make sense for storing surplus solar energy, but not for wind.”
“Pumped hydro is used in 99 percent of grid storage today,” Barnhart said. “It works fantastically from an energetic perspective for both wind and solar. Its energy return on investment is 10 times better than conventional batteries.”
Scientific American has published several thoughtful articles on Nuclear Energy. We have linked to several and will add others in the future. However, all the editorial board scientists must have been out sick when they approved Mark Jacobson and Mark Delucchi’s article, A path to sustainable energy by 2030.
The following is from a blog discussion triggered by the Jacobson and Delucchi article. We tried to contact the blogger for his OK to copy it, but he was just closing his blog and never replied to our request. Unknown blogger, if you see this we would like to give credit as you made some salient points and supported them with great research.
“You would be surprised to hear that wind power advocates, long defending their intermittency problem, have turned to the counteroffensive, criticizing the reliability of baseload plants. There are some truly ludicrous claims here. Here’s a sampling of the mendacity to which dishonest and deluded wind apologists are resorting to.
From Jacobson and Delucchi’s article: “A new infrastructure must provide energy on demand at least as reliably as the existing infrastructure. Wind, Wave, and Solar (WWS) technologies generally suffer less downtime than traditional sources. The average U.S. coal plant is offline 12.5 percent of the year for scheduled and unscheduled maintenance. Modern wind turbines have a down time of less than 2 percent on land and less than 5 percent at sea. Photovoltaic systems are also at less than 2 percent. Moreover, when an individual wind, solar or wave device is down, only a small fraction of production is affected; when a coal, nuclear or natural gas plant goes offline, a large chunk of generation is lost.
“Additionally, the Jacobson and Delucchi article claims that wind is “more reliable” than baseload because it has fewer maintenance outages (0-2% onshore, 0-5% offshore). This is a spectacular example of data cherry-picking: almost all wind power outage is due to weather, not turbine maintenance.
(Originally, we had connected the link below to the fact sheet on the AWEA website. On July 29, 2013 we were checking our links and discovered that the AWEA had completely overhauled their site and this fact sheet was no longer included. Our guess is that bloggers, like the one we are quoting here, did such a great job debunking this fact sheet that the AWEA deleted it. Luckily, we had downloaded a copy and the link below displays it. ENW)
Again from our unknown blogger. “Here’s the US wind industry’s PR front, the American Wind Energy Association (AWEA), in one of their question and answer fact sheets: AWEA-Wind-Power-Clean-Reliable.” (our copy}
“Is wind less “reliable” than conventional generation?”
“No. Conventional resources occasionally shut down with no notice, and these “forced outages” require operating reserves. For example, a power system that has a 1000 megawatt (MW) nuclear or coal plant will typically keep 1000 MW of other generation available, to be ready to quickly supply electricity if a plant unexpectedly shuts down. The power system can still be operated perfectly reliably in this fashion. Thus, “reliability” is not specific to any single generation facility; rather it is measured on a system-wide basis. Because significant generation reserves are already required to accommodate unexpected changes in electricity supply and demand, in many regions large amounts of wind power can be added to the grid without increasing the total amount of reserves that are needed.
“As noted by Jon Brekke, Vice President of Member Services for Great River Energy, a utility that operates in Minnesota and Wisconsin, “Wind energy is a valuable part of our diverse and growing energy portfolio. When partnered with other traditional generation resources, wind energy is an effective way to provide reliable, clean and affordable power to our member cooperatives. Geographic diversity of wind energy helps even out the variability of wind energy in the regional market. In addition, wind farms are typically made up of many individual turbines which reduce the impact of outages. For instance, there are 67 1.5 -MW turbines at our Trimont Wind Farm, so if one is down for maintenance, only 1.5% of the total wind farm’s generating capacity is lost.”
“Both Wind Power proponents make the same claim: that a collection of many wind farms is more reliable than a collection of large baseload plants, because they are smaller and hence an individual outage has a smaller effect.
“As a focus point: here’s some data I uncovered last year — the generating statistics of wind in Germany:
“This is the sum of four major utilities’ wind generation, for all of Germany over the month of January 2009. According to Wikipedia, statistics on wind power in Germany, there could be at most 24 GW capacity, and according to the data there is at least 16 GW represented; I’m not sure exactly how much capacity was online at the time, but it’s between 16-24 GW and probably towards the higher figure.
“For comparison, here’s a similar capacity of US nuclear power — 25.06 GW — NRC’s Region I, over the same time period (with the disclaimer that this performance is better than usual, as I will show shortly, because there were no refueling outages):
“This is the sum generation of the 26 NRC Region I reactors, according to power levels from NRC status data, and power capacities (net) from IAEA data. (That is: where a reactor is 1,000 MWe capacity, and recorded as running at 90% power level, I add 900 MWe). I’ve restricted to this 25 GW subset of the data to make a fair comparison with the 16-24 GW of wind capacity in the German data.
“It’s spectacular isn’t it? First, when Mark Jacobson says wind energy has “less downtime” than traditional sources — which as you can see on the wind graph, is, um, not quite the case. In his mind none of that obvious downtime on the graph counts. It doesn’t count because it’s not turbine downtime, but weather downtime.
“The big lie is that a collection of many wind farms is more reliable than a collection of large plants, because they are smaller and hence an individual outage has a smaller effect.
“You can see from the above power graphs this is obviously false. Why is it false? One obvious reason is that the uptimes of wind power are much lower than other sources (contrary to the egregious misdirection of Jacobson et. al). However, an even more crucial reason is the correlations between plants. Probabilistically, a grid of N power plants — if they are entirely independent — will never fail all at once, and their aggregate will act as a very reliable system. When plants go down, they go down at different times (with extremely high probability), and the rest of the system can be relied to back them up. As it happens, none of the four outages (A,B,C,D — two unplanned) in the nuclear graph coincided, and more broadly they will never all fail at the same time, like wind turbines do. There’s little or no correlation. (Actually, I suspect it may be better than uncorrelated – they may be anticorrelated, when flexible-schedule maintenance between units can be intentionally staggered, or shifted forward or delayed to counteract conditions at other plants.)
“However, wind power is massively correlated. It is correlated with diurnal cycles, it is correlated with seasonal patterns, it is correlated with weather fronts over thousands of miles of space… completely separate wind farms are all correlated together, rising and failing in synchrony. You clearly see this in action in the German national data — 20,000 turbines, scattered hundreds of miles apart, all failing at the same time. That’s the key: correlation. When wind advocates claim that the failure of an individual wind, solar or wave device, affects only a small fraction of production, they are misdirecting you from the obvious. That wind generators don’t all fail at one time, but they all stop generating at the same time.
“I mentioned that the nuclear performance is unusually good, because there are no refueling outages included. The US nuclear capacity factor is around 90% although on the short term it ranges from 80-100% (dark blue):
“(Same NRC data, now for a 12-month period.) I’ve added a gray line for the total US electricity consumption for each month (arbitrarily normalized; source is EIA). The key feature missing the January data is refueling outages, which cluster in spring and fall. I’m pretty sure this is deliberate; they are in the months of lowest demand (according to the gray line); a sort of load following. You see dozens of unplanned outages over the year as well, but clearly they are totally uncorrelated, and the collection of nuclear plants is infinitely more reliable than a whole country of wind farms.”