Over at Climate Crocks, Christopher Arcus
cites an article at Scientific American on the efficacy of wind power for reducing grid CO2 emissions
. Unlike other pieces I've seen on the subject, that one fails to cite any sources for its conclusion which is:
even if wind produced as much as 50 percent of Spain's electricity the CO2 savings would still be 80 percent of the emissions that would have been produced by the displaced thermal power stations.
This appears to be possible, if the rest of the grid mix is compatible. Hydropower is particularly well-suited, as it has no thermal-cycling limits and little in the way of startup delays. However, hydropower cannot be assumed to be present with the wattage and water storage required. Kodiak island can up its wind power and go diesel-free (so long as electric demand doesn't rise too high), but the rest of the world must deal with other constraints.
One of these constraints is the increased emissions due to more startups and low-load operation of powerplants that would otherwise run more efficiently; this leads to the net reduction in CO2
emissions from most RE being substantially less than their gross contribution to the grid. Argonne National Lab studied this, and stated this in the abstract of the paper
Our results for the power system in the state of Illinois show significant emissions effects from increased cycling and particularly start-ups of thermal power plants. However, we conclude that as the wind power penetration increases, pollutant emissions decrease overall due to the replacement of fossil fuels.
The question becomes, how MUCH do pollutant emissions decrease? There's no fine print in the abstract's text, but what the words giveth, the graphic taketh away:
There's one obvious anomaly in the graph: it strains credulity that the total emissions can decrease proportionally faster than the total fossil generation, as it does at the left edge. This could be due to an error in the baseline introduced by a graphic artist. But aside from that, the emissions curve is distinctly concave upward; well before the middle of the curve, total emissions do not fall as fast as total wind penetration. There's the further question about the total amount of wind generation usable. To achieve more than 40% penetration, the capacity factor of wind would also need to be on the order of 40% or else available power would frequently exceed total demand. Without storage, the excess generation would have to be "curtailed" (spilled). This increases the net cost per kWh.
Using my Gimp-fu to extract data points from the graphic, I get this table of data:
|Penetration, % ||mmMT CO2 ||% reduction |
|0 ||41.7 ||0.0 |
|10 ||37.0 ||11.3 |
|20 ||33.1 ||20.7 |
|30 ||30.1 ||27.7 |
|40 ||28.2 ||32.4 |
By 40% penetration, the total emissions reduction from wind has fallen to 81% of its contribution; worse, the total emissions reduction between 30% and 40% wind penetration is just 4.7%, less than half of the fractional addition to generation. This is well into the region of diminishing returns.
According to climate scientists, keeping total climate warming below 2°C¹
requires no less than an 80% reduction in total GHG emissions. Even if we could draw a straight line between the 30% and 40% data points to a hypothetical 100% "penetration" way off the right edge of the graph, the total emissions reduction would only be about 61%; net emissions would still be twice as high as we can allow them to be. Of course, expecting that curve not to bend upward to the right of 40% is a pipe dream.
I hear the objection coming up immediately: "But wind isn't all there is. Solar and other technologies can fill the holes in wind and push emissions down further!" Sadly, solar PV (which is the only kind we're likely to see in private hands or outside sunny deserts) has a very low capacity factor; Germany's is about 11%. Achieving more than 11% penetration gets into the same region where generation exceeds instantaneous demand, and the excess must be stored (expensive) or spilled (driving up cost per kWh, and also requiring a control system to manage generation). Last, the emissions reductions from PV will be subject to the same diminishing returns evident for wind.
- It is broadly true that the addition of wind power to electric grids dominated by fossil-fired plants can reduce total pollutant emissions, including CO2.
- The substitution rapidly runs into diminishing returns (unacknowledged or even denied by the advocates).
- The claims that even an 80% reduction in carbon emissions from electric generation can be achieved with the addition of wind and solar are far-fetched and not credible. Absent other carbon-free generation using large amounts of stored energy (e.g. conventional hydro), a zero-carbon RE grid should be viewed as nigh impossible.
Because of this, if we expect to de-carbonize our supply of electricity (and energy in general) we have to look to sources other than "renewables".
(A hat-tip to Willem Post
for bringing the Argonne paper up!)
James Hansen and others opine that 2°C is well past the safe zone, and we need to shoot for no more than 1°C. This requires a much lower ceiling on emissions, achieved much sooner.
Labels: renewable energy, storage, variability
This is a short piece I need to get out just so I can put all my attention on the major post I'm working on.
Germany's shutdown of many of its nuclear plants has led quite directly and inevitably to increased burning of fossil fuels. (Canadian Energy Issues
pegged this.) Contrary to the false claims of Chrisopher Arcus on ClimateCrocks
, all German coal-fired generation has risen, both hard coal and lignite. This isn't some right-wing claim, it comes straight from the Rocky Mountain Institute
The Energiewende can only be described as schizophrenic:
- It is represented as "green", but policy decisions are driving consumption away from low-carbon gas and zero-carbon nuclear to the dirtiest fuel on earth, coal.
- It is represented as a "transition", but to date it's more of a return to the 1950's than anything forward-looking.
- Subconciously it might be an effort to reduce dependency on Russia, but if that was the case, why shut down nuclear plants which could be used to slash gas demand much further?
Then again, how can we expect sensibility from people who panic about tsunamis in the middle of Europe? Sie sind wahnsinnig.
Don't ever think I don't like my new Fusion Energi. It's literally the best car I've ever had. But you have made some extremely annoying, unsettling or just plain counter-productive decisions (or bugs) in the software, and I wish you'd fix them.
Some of these are weird behaviors that have no obvious explanation:
- The other day I was on a relatively long trip driving on cruise control, and the graphics around the "ECO" symbol on the left-side dash display changed to vertical dotted lines. This has happened before, but what followed had not. From time to time the right-side dotted line flashed red, accompanied by a pattern of 3 pulsed vibrations on the right side of the car. There was no text pop-up to explain what was going on, and obviously it is not safe to search the owner's manual while driving. I was eventually persuaded to pull over and examine the tires to see if something was wrong with them. I found nothing, and the strange behavior went away after the stop. I still have no explanation for this.
- Sometimes when I park and return to the car, the side mirrors are turned all the way down and I have to reset them properly. This has occurred on any number of occasions, sometimes after just minutes away.
- There is a bug in the charging system. Sometimes when I plug in a charger, the car does not recognize it and refuses to charge. The charger can be un-plugged and re-plugged as many times as desired, and the car will still not charge. I had the convenience cord replaced under warranty because of this, with no change; I later reproduced this problem on a public charger. I finally discovered that cycling the ignition would get the car to charge.
But my biggest irritations are things that I ought to be able to get, but you deny me.
- The 12-volt power points shut off when the ignition is off, even when the car is plugged in and charging. There should be no danger of running down the accessory battery, so I fail to see the justification. Maybe I'd like to leave devices plugged into charge; why can't I?
- Even worse, the 150-watt AC outlet in the center console doesn't work at all when the car is charging, even when the ignition is on! I may have 3 kilowatts coming in through the socket on the fender, but I can't get a lousy 150 watts to charge a laptop. That requires a second cord running to another outlet... IF one is available. It is bizarre to be able to run the car's air conditioning from "shore power", but not a single AC-powered device.
- And at the very basics, how about the electrical specs for the charging port? I am interested in buying a 220 volt charger to install at home. Of course, I am interested in getting the best charging performance the car will allow, for my own convenience and to electrify as much of my driving as I can. I can get chargers that go all the way up to 30 amps, but the higher currents cost more money. How much current will the car accept? YOU WON'T TELL ME! There is NOTHING on the car, in the owner's manual, or on-line that lists the basic electrical specifications that you'll find on a string of Christmas lights. How about coming clean here? My laptop power brick says "INPUT: 100-240V~ 50-60Hz 1.5A", it won't kill you to do the same.
If you really want to thrill me, open up the full specs for the car's high-voltage systems and put me in touch with your product-development engineers. There are a whole heap of options and applications that you haven't touched, and all you need to turn the marketplace loose is an open specification for plugging in. Play your cards right and you could start the PC revolution, only with plug-in vehicles. Think about it. But don't think too long, because the rest of the world is ready to steal a march on you.
It was 71 years ago today, December 2 1942, when the very first controlled nuclear chain reaction on earth was started in the "atomic pile" built in the squash court at the University of Chicago. Rod Adams has more details
Exactly 15 years later, the first commercial nuclear power station at Shippingport went critical for the first time. Thus swords were beaten into plowshares, and 56 years on some 1.8 million people who would otherwise have lost their lives to air pollution from fossil-fuel combustion lived instead.
Now we need to clear the air of something far less obvious than smoke and acids, but much more critical to the earth. Let's hope we wise up in time.
Labels: CO2, editorial, nuclear power