Jeffery Sachs of the Columbia Earth Institute has an excellent commentary in Scientific American this month on the disconnect between the Wall Street Journal editorial board and their own reporters (and the rest of the world) when it comes to climate change. He challenges them to truly follow their interest in an “open-minded search for scientific knowledge” by meeting with the “world’s leading climate scientists and to include in that meeting any climate-skeptic scientists that that the Journal editorial board would like to invite”.
RealClimate heartily endorses such an approach and, while we leave it to others to judge who the ‘world leading’ authorities are, we’d certaintly be willing to chip in if asked. To those who would decry this as a waste of time, we would point to The Economist who recently produced a very sensible special on global warming and proposed a number of economically viable ways to tackle it, despite having been reflexively denialist not that many years ago. If the Economist can rise to the challenge, maybe there is hope for the Wall Street Journal….
Re 226 and 249
Writing as someone who knows something about both:
The Chelyabinsk waste tank explosion resulted from a loss of cooling in a tank designed to require cooling the remove the heat generated by the radioisotopes. From my point of view, it was a failure of safe engineering design from the same folks who figured how to make a low-enriched uranium-fueled reactor (Chernobyl) go prompt critical.
The Hanford waste tanks were designed not to require cooling for the waste stream they were sequestering. Around a fourth of the early 147 single shell tanks leaked to soil, as a result of corrosion, primarily along the waste/air interface on the side walls of the tanks. After it became clear that some of the tanks were leaking, 28 double shell tanks (with monitoring of the internal annulus) were built and put in service. None of the double shell tanks have leaked. The Hanford waste tanks sit about 400 feet above the water table, 400 feet of mixed sand and volcanic ash soil. Most of the leaked radionuclides, and, in particular, the uranium and plutonium, bind strongly to that sort of soil, and little of the approximately one million gallons of high-level waste that leaked from the single shell tanks has reached the water table. The Hanford operations (which, you should note, were military plutonium production operations, not a civilian nuclear power facility) had a second waste stream with high volumes of liquid but low concentrations of radionuclides. That waste stream was essentially dumped directly to the soil and did migrate to the water table and eventually to the Columbia River. However, that waste stream was also subject to radionuclides bonding chemically to soil and to basalt and was massively diluted by the flow of the Columbia River — due to Hanford’s desert environment, groundwater flow rates are low.
Until we moved into our new house, I drank water from the Columbia, downstream from the Hanford Reservation for 25 years. At no time during that 25 years was the concentration of any radionuclide in the downstream Columbia even close to the EPA drinking water limits.
Hanford nuclear waste, like commercial nuclear wastes has been well-sequestered from the biosphere, with the exception of the first few years of operations. The public health effects of those first few years have been extensively studied (to the tune of 10s of millions of dollars). The effects, if any, were too small to be detected by a fairly large epidemiological study.
Best regards.
Jim Dukelow
Re #241 and #244
The Economist Survey is certainly suggesting that there is a general concensus that 550ppm is not too bad.
In Dismal Calculations we read:
“Many experts would settle for stabilising the carbon content of the atmosphere at around 550 parts per million. There is no particular magic to that figure, but given that carbon concentrations are now at 380ppm, it looks achievable and does not make most scientists’ hair stand on end.”
And in Where to Start we read:
“The concentration of CO2 in the air has risen from 280ppm before the industrial revolution to around 380ppm now, and the IPCC reckons that if emissions continue to grow at their current rate, by 2100 this will have risen to around 800ppm. Depending on population changes, economic growth and political will, this could be adjusted to somewhere between 540ppm and 970ppm. The prospect of anything much above 550ppm makes scientists nervous.”
Hank, your link is broken; you accidentally included a period at the end of the url. This causes wordpress to include the period in the link it creates, resulting in a broken link.
Here’s my attempt:
http://faculty.washington.edu/smgard/GardinerStorm06.pdf
Re 245
Just curious how well do we understand the impact of all the acid rain your proposal will inflict on the global ecosystems?
Can you for example elaborate on the effects it may have on amphibian populations in Central American rainforests and how that may affect predators that feed on them.
How about the consequential natural selection of acidofilic microorganisms over those that thrive in a more alkaline aquatic environments in the Amazonian tributaries and the entire food webs that may be affected there.
I supposed you are completely comfortable with your understanding of how the possible acidification of the oceans will affect coral reef ecosystems?
I have to assume that you have at your disposal much more sofisticated computer models of all the paramaters that exist in ecosystems than for example the climate scientists have of global climate models.
Forgive me for being extremely sceptical of such proposals. I would much prefer an effort at major paradigm shifting away from our current unsustainable status quo. I realize that my personal veiws are not yet quite mainstream, however it seems to me that an emphasis on continued reduction of carbon based fuels and more research and developement devoted to increased energy efficiency may be a better investment.
I know that many out there have vested interests in continuing to state the negative impacts of implementing alternative energy sources on a very large scale.
I would at least like to see some mechanisms in place to hold those that propose such schemes as releasing sulfur aerosols into the atmosphere accountable should such schemes backfire and cause unintended consequences.
Granted I don’t expect that to really happen and once the damage is done it may be a bit like executing a murderer, it neither brings back the deceased nor does it really provide much comfort for those that have to live on without their loved one.
Re #252, Well if Scientists are not concerned too much by emissions rising another 170 ppm or and additional 270 billion tonnes of free Co2 then by that time we would have probably run out of fossil fuels anyway and hence there is no issue and hence there is no need for Real Climate to exist.
Unfortunately that is not the evaluation of James Hansen (Head of GISS) who states that we have perhaps 10 years to avoid potentially serious climate change. Why does he say this do you think, well I would say it is because the climate is not as the computer models would have us think and that something is missing from them, because the actual evidence of climate is more abrupt than that. Things are melting and stressing faster than the climate models predict.
Maybe Real Climate should comment on this directly. 100 ppm added since 1850 has equated to around 0.6 C in warming I believe. Another 170 ppm added by 2100 would equate to another 1.0 or 2.0 C in warming which is not considered to be too drastic? If this is the case then by 2100 all fossil fuels will be exhausted and hence no problem, just a warmer world with higher sea levels. Nothing to drastic.
Re #252:
We have enough fossil fuels to reach 550 ppm and far beyond that. 1,000 ppm can easily be reached using current reserves of coal, oil, and gas alone. Throw in extra resources becoming reserves because of rising prices or better technology, new discoveries, and unconventional sources such as tar sands, peat, and heavy oil and we can probably reach 2,000 ppm and possibly much higher. Even if we don’t burn most of the peat in power plants, much of it will probably oxidize or undergo methanogenesis because of land use changes (tropical peat) and global warming (arctic peat).
As far as the 100 ppm rise goes, the current effect is 0.6C, but the end effect will be more once the oceans have a chance to catch up. 550 ppm is expected to cause between 1.5C and 4.5C of warming. 4,000 ppm (my rough guess as to what uncontrolled fossil fuel burning will eventually give before we run out of the stuff) will give a 6C to 18C increase (assuming a clean logarithmic response to more CO2 – a big if).
Re 203
Mystery writer Secular Animist writes:
‘A study published in March 2005 by The Energy Foundation found that “Residential and commercial rooftop space in the US could accommodate up to 710,000 Megawatts of solar electric power … for comparison, total electric-generating capacity in the US today is about 950,000 MW.” In other words, if the existing siting capacity for rooftop photovoltaics was fully exploited, it could produce nearly 75% of the USA’s current total electricity generated from all sources.’
Well, that’s not really what the Energy Foundation report says. First, p. 2 has the disclaimer
“This report must be read in its entirety. It is important that the reader understand that no representation is made as to the accuracy or completeness of content of this report. No person has been authorized by Navigant Consulting Inc. to provide any information or make any representation not contained in this report. Any use which a third party makes of this report, or any reliance upon or decisions to be made based on this report, are the responsibility of such third party. Navigant Consulting Inc. does not accept any responsibility for damages, if any, suffered by a third party based on this report.”
Second, the report’s 710,000 Megawatts of solar electric power are very different megawatts than the 950,000 MW of existing electrical capacity. Base-loaded coal, hydro, and nuclear plants will operate at a capacity factor of 80-90%. Natural gas turbines are used for load following at capacity factors around 15-20%. The Navigant Consulting report uses units “Wpdc”, which they define as “the amount of power a PV device will produce at noon on a clear day with sun approximately overhead when the cell is faced directly toward the sun.” With early mornings, late afternoons, clouds, and nighttime, we are talking about a capacity factor (Whours produced per Wpdc) on the order of 20-25%, averaged over a year. Thus, the hypothetical 710,000 Mwatts of solar electric on rooftops correspond to about 30% of the electrical generating capacity of the 950,000 Mwatts of existing electrical capacity, not 75%.
Third, the reader of SecularAnimist’s posting should be aware of the speculative nature of Navigant’s market projections. They are based upon a hypothetical price breakthrough for PV installed capacity, a roughly 50% reduction by 2010 from the hypothetical installed price of $5.30/Wpdc (hypothetical because it is not the current installed price, but rather assumes a continuation of current price reduction trends up to 2010).
Fourth, I too have been watching/listening with interest to the buzz about thin-film PVs, which is given some credence by the money that venture capitalists are pouring into the companies pursuing the research. The caveat is that these are the same venture capitalists that poured money into Internet companies in 1998-99. I do agree that, if the research comes to fruition, it will be a market-disruptive technology. On the other hand, when I was studying nuclear engineering, I formulated the aphorism “nothing works as well as a paper reactor”.
Best regards.
Jim Dukelow
Re 218 and 225
Eli Rabett wrote:
“The issue of base load is an interesting one. In the same sense that solar/wind is not suitable for baseload, nuclear is not suitable for peak demand situations (you don’t want to ramp a nuclear reactor up and down and up and down”
Gar Lipov wrote:
“But France has its own hypocrisy. French nuclear electricity would not be so cheap if it could not supply power to other EU nations. Nuclear power plants take days (or at least a good fraction there of) to shutdown or bring back up. But power demand varies from a minimum to maximum. The mimimum (base load) tends to be responsible for about 40% of total kWh consumption ovwer the course of 24 hours. France is able to provide nuclear electricity at a higher level of output than this only by selling surpluses to other nations during off-peak demand. If Germany, Italy, et. al. stopped purchasing this surplus, making up the lost revenue would require almost doubling the cost of nuclear supplied electricty.”
Most nuclear plants are quite capable of following the daily load cycle. What they can’t do is follow flucuations on a time scale of a few minutes. For that, gas turbines or hydro plants are needed. The assertion that France “needs” the export market for their nuclear plant electricity is simply not correct. I am sure they enjoy the foreign exchange benefits of that market, but if necessary they could follow the daily load cycle of their domestic market.
Best regards.
Jim Dukelow
Re 229
An electrical grid is a large dynamical system. A useful analogy might be to consider it to be a complicated network of linked bungie cords of different lenghts and strength. The aspect of the grid that imposes practical limits on the fraction of wind and solar is the grid stability. If you cut one of the bungie cords, a disturbance will run through the whole grid and can, under some circumstances, set up oscillations whose amplitude far exceeds the initial disturbance and exceeds the capability of the grid-protecting components. The great Eastern blackout of a couple years ago and the two large Western blackouts of around a decade ago were examples of that sort of grid destabilization.
Best regards.
Jim Dukelow
Re#256
We do not have enough fossil fuels for 2000 ppm. Oils current known reserves are just about 1.2 trillion Barrels or 30 years worth an natural gas around 40 years worth. Forget tar sands and the like, the are a last desperate attempt to keep fossil fuels alive but they are too water and energy intensive to work.
Only Coal is a big player, possibly some 270 years worth left but not at present and projected rates of use.
Regarding C02 ppm
First relevant events from history suggest a 2-3000 ppm during such scenarion.
Also what is the tipping point for C02 ppm — leading to the sudden release of methane, from oceans and permafrost? At last teh tipping poit of permafrost sediments is here allready.
And how much % will this contribute to the current greenhouse gas?
Is there even 1 single model for this?
If we focus on fixed C02 ppm air numbers, user want get the big picture. because with a suggested sudden methane release we likely to double – tripple the greenhouse gas concentrations?
>Most nuclear plants are quite capable of following the daily load cycle.
Not really, or at least not except by discarding power. A nuclear power plant really has two setting – “on” and “off”. You can’t throttle down a nuclear power plant in any meaningful sense. So there is no way a nuclear plant can do load following inexpensively. Of course what you can do is throttle down the heat engines that use heat from nuclear p ower plants. But they are producing the same heat; you are simply throwing away more of it – just as in some cases electricity from a wind generator has to be discarded. So your statement that a nuclear power plant can follow the daily load does not seem to be supported – unless you want to multiply your per kWh cost by three.
>An electrical grid is a large dynamical system. A useful analogy might be to consider it to be a complicated network of linked bungie cords of different lenghts and strength. The aspect of the grid that imposes practical limits on the fraction of wind and solar is the grid stability.
Yep, and most people who have looked at it seem to think that without storage and without very high costs, that limit is 20%. (I have seen outliers that suggest 10% or 30%, but 20% seems to be the conclusion by the overwhelming majority who have looked at it.)
This is of course without storage. Add even small amounts of storage and the percentage goes up substantially. And we can achieve small amounts of electrical storage in two ways. We can use flow batteries which are very expensive per kWh, but can be done inexpensively if used to store very small amounts of electricty at very high capacity and capabilities. (You can think of them as the next step after super-capcitors. Super-capacitors store nano-seconds to seconds worth of electricity to bridge the time between a power loss and spinning reserves coming into play. Flow batteries can economically store up to fifteen minutes power, serving as spinning reserve. That means actual spinning reserves can be replaced by operating reserves capable of being brought on-line in 15 minutes or less (hydro-electric, geothermal, solar-thermal with storage, natural gas, diesel). Alternatively we can use small amounts of pumped storage. (Pumped storage is cheap, and we could use large amounts of pumped storage if we had it. But pumped storage is limited by requireing by requiring rare geographical features and having disasterous ecological consequences.)
In other words you can get (arguably) low carbon base load (~40% depending on what percentage total load base represents) from nuclear power. You can get perhaps 5%-10% all-purpose(base,peak, intermeidate and load following) from really high quality sources such as hydro-electric, geothermal and biomass. (Biomass in electric generation is normally burned as solids, and is base load like coal. But you can gasify biomass and run combined cycle turbines, thus supplying any part of the load cycle you wish.) A well managed grid without storage can tolerate around 20% of supply from variable sources without disrupting stability or reliablity. A small amount of electrical storage can extend the percent of variable electricty that can be tolerated.
If we are to have a low carbon grid, that still leaves a huge gap which requires large amounts of storage not small amounts of storage.
The only means of doing large scale storage at a reasonable price (large scale compared to world electricity consumption I mean) is high temperature thermal – which as far as I know only works with solar thermal. I know it has been looked into for nuclear and fossil fuel plants – but the problem there is that fossil fuel plants use much higher temperature heat than solar thermal, and nuclear plants are designed to use higher temperature heat than fossil fuel plants. The higher temperature heat you are storing, the more expensive storage medium is required to begin with, and the hard it is to retain the heat. (Higher delta-T either produces faster thermal losses or requires better insulation. And the higher temperature heat you are storing to less choice you have for insulating material.)
So, unless you want to assume breakthroughs in storage or generation technologies, you will need a high percent of solar thermal with thermal storage as part of the electric grid mix. You could use hydrogen or flow battery storage, but that is going going to cost much more than thermal storage. You could build nuclear reactors to peak storage requirements, and discard the electricity off-peak but again you are multiplying your per kWh cost many times.
Now you could still argue for just this mix – Nuclear for base, hydrolectric, geothermal, biomass to the extend practical for shaping, variable sources such as wind with small amounts of electrical storage as “filler” to lower total costs, and solar thermal with storage for fully dispatchable power above what the hydroelectric et. al. could provide.
But what you must acknowledge that we are going to need large amounts of solar thermal with storage regardless of whether we use nuclear electricity, and once you realize that solar thermal with storage can replace nuclear electricty, and actually provide higher quality electricty in terms of grid stability,it becomes hard to argue that we should build nuclear/solar thermal mix rather than a greater number of solar thermal plants.
RE: 254 Before you remand me to the Hague for trial I would point out in my defense that I did state in my complete report the following: “Other issues that must be addressed: impact on engine performance and operating life, impact on stratospheric ozone, tropospheric air quality, uneven cooling of the atmosphere and ocean acidification.”
Regarding the issue of acid rain that keeps coming up, the amount of sulfate aerosol that would be added by my one-day-at-a time scheme is pretty tiny by comparison with power plant emissions and even over a year’s time would probably not have any detectable impact on biological ecosystems. The more important concern would be the effect on stratospheric ozone, something else I said should be investigated.
BTW, if my schemes work, do I get a big reward?
What a remarkable weakness for power plants whose ancestors are naval propulsin reactors to have. And yet winter is of so little concern in re solar power plants that one need never even mention it …
[edited]
[Response: Please keep it civil, or take it somewhere else. – gavin]
Question for moderator:
I just tried to post a message responding to Gar Lipow’s post 262. RC rejected it as containing spam-like elements. I can’t think of anything in the message (which I would have to re-create, as it has disappeared at this end) that would be considered spam-like. I would appreciate if you would review the attempted posting and post it, if appropriate.
Thanks.
Jim Dukelow
[Response: We never see messages that get immediately rejected. Try the browser back button to recover. Remove all references to ‘mortgages’, poker, loans etc. Email the message to contrib-at-realclimate.org if you can’t work out the problem. Sorry for the inconvenience. – gavin]
Re 262
Gar Lipow wrote:
“The only means of doing large scale storage at a reasonable price (large scale compared to world electricity consumption I mean) is high temperature thermal – which as far as I know only works with solar thermal. I know it has been looked into for nuclear and fossil fuel plants – but the problem there is that fossil fuel plants use much higher temperature heat than solar thermal, and nuclear plants are designed to use higher temperature heat than fossil fuel plants. The higher temperature heat you are storing, the more expensive storage medium is required to begin with, and the hard it is to retain the heat. (Higher delta-T either produces faster thermal losses or requires better insulation. And the higher temperature heat you are storing to less choice you have for insulating material.)”
As with many of the things Gar has been writing lately, he has this exactly backward. Fossil-fuel plant operate at higher temperatures than nuclear plants (that is, they feed higher temperature, higher pressure, higher enthalpy steam to the steam turbines that produce the electricity). That is why nuclear plants operate at a thermal efficiency of 32-34%, while fossil coal- and natural-gas-fired plant have thermal efficiencies around 40-45%. A corollary is that a nuclear plant will reject more heat to the environment for each kwhr produced than a fossil plant.
Best regards.
Jim Dukelow
Jim Dukelow wrote: “I just tried to post a message responding to Gar Lipow’s post 262. RC rejected it as containing spam-like elements.”
This happened to me once. I emailed RC and found out what the offending word was: “m o r t g a g e” but without the spaces between the letters (in reference to financing residential rooftop photovoltaic systems to reduce upfront costs).
It would be a nice enhancement to the spam-filtering feature of the site if it could be programmed to inform the commenter at the time the comment is rejected of the reason for the rejection, and provide an opportunity to edit the comment to remove the (probably almost always inadvertently) offending content.
>As with many of the things Gar has been writing lately, he has this exactly backward.
Umm so far about the only thing you have been able to rebut successfully, and a minor point. Both Coal and Nuclear Power operate at a higher temperatures than solar thermal. So thermal storage for them is more expensive than for solar power. I note you still have not explained how nuclear power can do load following.
>What a remarkable weakness for power plants whose ancestors are naval propulsin reactors to have. And yet winter is of so little concern in re solar power plants that one need never even mention it
…
Ignoring the nastiness, I will deal with the valid points.
Nuclear submarines don’t have to try to keep dollar per kWh competive with fossil fuels. Nuclear power plants that are designed to provide commercial electricity are on and off period. Don’t know why you are disputing this point so stridently. It is widely recognized, and base load power is one heck of an important contribution; you sure as heck are not going to get base load from wind or photovoltatics – even if thin film drops by a factor of five (about which I am skeptical).
And concerns like winter and cloudy days is why solar thermal generators need to be placed in deserts – so that they have signficant amounts of sunshine summer and winter. That keeps storage needs to days rather than months.
Re 263
“BTW, if my schemes work, do I get a big reward?”
Sure, but ocean acidification and acid rain are not exactly separate issues.
Even if what you say is true about the amount of sulfate aerosol that would be added by your one-day-at-a time scheme being pretty tiny by comparison with power plant emissions and even over a year’s time would probably not have any detectable impact on biological ecosystems.
I would still like to have a little more empirical data available on which to base the final decision to go ahead with such a plan.
I’m just not convinced that that information is currently available, if you know otherwise then please be so kind as to share it.
I am not suggesting that you be remanded to the Hague for trial, I actually applaud your attempt at looking for solutions. It’s just that I believe that this particular solution is like putting a dirty band aid on a severed artery. If we don’t change our ways of doing things at the most fundamental of levels the fact that the band aid will cause an infection is almost irrelevant. We need a tourniquet to staunch the flow then we need to stitch the artery shut!
Then we need to learn to stop trying to punch through plate glass windows with our fists.
Re 262, Gar Lipow wrote:
“>Most nuclear plants are quite capable of following the daily load cycle.
Not really, or at least not except by discarding power. A nuclear power plant really has two setting – “on” and “off”. You can’t throttle down a nuclear power plant in any meaningful sense. So there is no way a nuclear plant can do load following inexpensively. Of course what you can do is throttle down the heat engines that use heat from nuclear p ower plants. But they are producing the same heat; you are simply throwing away more of it – just as in some cases electricity from a wind generator has to be discarded. So your statement that a nuclear power plant can follow the daily load does not seem to be supported – unless you want to multiply your per kWh cost by three.”
Like so much of what Gar has been writing lately, this is just flat wrong. G. R. L. Cowan correctly noted that this would be an amazing characteristic for a type of reactor initially designed to power warships and, in particular, submarines, which are exquisitely vulnerable to an unexpected loss of power.
In fact, commercial nuclear reactors have an array of shutdown and control rods and chemical reactivity control. The shutdown rod can bring the reactor to zero fission power in about a second, not the “hours” that another poster alleged. The control rods and chemical reactivity control can modulate the power smoothly between zero (shutdown) and 1 (full power) and do it on a time scale that allows the reactor to follow daily load cycles without any difficulty. As they do that, the amount of heat generated is proportionately reduced; the plant does not simply make less electricity and discard more of the heat generated at full power.
There is a strange “gotcha” in reactor control. If the reactor scrams (the one second shutdown), the operators have only a few minutes to bring it back up to power (a process of a few hours for a normal startup). Past that time, radioisotopes of xenon and samarium build up in the reactor. These isotopes are strong neutron absorbers and “poison” the reactor core to the point that it cannot be started up until the xenon and samarium have decayed away, a matter of a few hours (6-24, depending on how long the reactor had been operating at power prior to the shutdown).
This xenon poisoning, an inconvenience for an electrical utility, can be life threatening for a submarine operating at depth. After the Thresher accident, a battle scram bypass was added to submarine reactor controls, allowing the captain to maintain the reactor at power when the safety ciruitry would otherwise generate a scram.
Although power reactors can follow the daily load cycle, most cannot not easily follow higher frequency oscillation in the grid load. Thus, even in a utility like Electricite de France, whose reactors do follow daily load, some rapid-response “peaking” generation is required to follow load variation on the scale of a few minutes up to a couple of hours.
If a commercial reactor ramps down to half power for half the day, say, there will be a modest increase (a few percent, not a factor of three) in the cost of power generated during that time, since the fixed costs of the reactor (cost to build the reactor, cost to pay the employees, etc.) are being spread over fewer kwhrs being generated.
A good policy for RealClimate posters would be to write about things they know and understand or, at least. preface the others with “I have read/heard” followed by an indication where they read or heard it.
I read and heard my information above during the course of a thirty-year career as a nuclear engineer and a risk analyst.
Best regards.
Jim Dukelow
It isn’t what you know that hurts you. It is what you know that isn’t so.
On renewable energy, efficiency, and economics I do have expertise and generally cite sources for everything I say. On nuclear power and utilization, I bought into a myth. Sorry.
Re #262 & related:
“That is why nuclear plants operate at a thermal efficiency of 32-34%, while fossil coal- and natural-gas-fired plant have thermal efficiencies around 40-45%. A corollary is that a nuclear plant will reject more heat to the environment for each kwhr produced than a fossil plant.”
Now this is something that has puzzled me, and since we have an experienced professional on board, I’ll risk getting off-topic. Shouldn’t the waste heat from a nuclear reactor be coming out of the turbines at roughly boiling point? I know that the geothermal power plant up the road from my place manages to generate useful quantities of electricity from such a low-temperature resource, so why can’t/don’t nuclear plants do the same?
Similarly, when I worked for an electric utility some years ago, there seemed to be quite an effort to find uses for the waste heat from its conventional generating stations. IIRC they had things like a vegtable processing plant, and were even raising tiliapa (sp?) fish in the warm waters of the cooling ponds. (One chap even wanted to start an alligator farm :-))
Seems to me that if such things can be done, the heat is no longer “waste”, but a useful secondary resource, yet my perception is that either very little of it is being done, or it is not widely known.
Re 270:
“Although (nuclear) power reactors can follow the daily load cycle, most cannot not easily follow higher frequency oscillation in the grid load.”
This is interesting. Does the same apply to coal-fired power stations? This has some relevance to generating systems that also have wind-generators and hydro-generators e.g.
“some rapid-response “peaking” generation is required to follow load variation on the scale of a few minutes up to a couple of hours”
If there are wind-generators then the “peaking” generation (from hydro e.g.) also compensates for the wind-generator variation.
Re 272 and 273
Some of the details below may be slightly off, because I am working from memory, which, as we all know, is the first to go — or is it the second?
Responding to James:
The steam that makes it all of the way to a nuclear plant or fossil plant condenser is, in fact, near the boiling point, but at a temperature of around 70-80 deg F, the boiling point of water at the low vacuum of the condenser (1-2 psi absolute). The steam cycle side of nuclear and fossil plants is marvelously complicated, designed so in the pursuit of the last few fractions of a percent of overall plant efficiency and plant reliability. Steam is bled off at various points in the cycle at various temperatures and pressures and routed to reheaters, which take the low temperature condensate being pumped toward the reactor vessel or the fossil steam generator and cumulatively heat it up to an inlet temperature that is only 20-40 degrees cooler than the eventual steam/water outlet temperature. Doing this increases the thermodynamic efficiency of the steam cycle and reduces the thermal stresses in thick metal components that would result if they were heated or cooled rapidly.
This last bit also indicates that some of the factors that limit the load following of nuclear plants to relatively low frequency load variations are also operating in fossil plants, in order to keep thermal stresses in the large steam turbine components within acceptable limits.
Responding to Chris:
Peaking plants or what utilities refer to as spinning reserve are required to compensate for load (that is, demand) fluctuations and to compensate for fluctuations in generation. However, dealing with generation fluctuations from 400 one megawatt wind turbines spread over a large geographic area is a more difficult issue that dealing with larger generating facilities that may go offline at unpredictable times. My understanding is that careful studies of grid dynamics have led to the general conclusion that up to 20% of grid generation from wind/solar can be reasonably accomodated, but above that grid stability becomes a problem.
The grids most able to accomodate lots of wind generation are those, like Bonneville, in the Pacific NW, that have lots of hydropower, in effect lots of energy storage, that can be used for rapid dispatch and spinning reserve.
Best regards.
Jim Dukelow
RE # 274
Jim, your contributions to the discussion of intermittant power sources and need for backup to provide stability to the grid are superb.
I hope readers are beginning to understand [that up to 20% of grid generation from wind/solar can be reasonably accomodated, but above that grid stability becomes a problem.]
That is the fact and renewables advocates have to accept it. Then, we can open the discussion to the remaining additional 60 percent (+???) decarbonization challenge ahead of us. At least we should be playing with a full deck.
Re #272:
In an efficient turbine or reciprocating engine, the waste heat is at room temperature (or even lower if you have a cooler sink to dump into). They’re called condensing steam turbines, and the steam is condensed at pressures and temperatures well below 1 bar/100C in a heat exchanger. If you want to use the waste heat for heating (co-generation), you need to increase the outlet temperature/pressure (maybe to 2 bar/110C for district heating, or even higher for some industrial uses), which will reduce the efficiency of the turbine.
Steam engines/turbines have even been run using water at around 25C (with the sink being 4C) by operating at sub-atmospheric pressures.
Re #274, 275:
The grid is as inflexible as it is because it saves capital. If we’re willing to add extra capital, we can push far beyond that 20% boundary.
As an example, reciprocating (piston) engines in the MW range can be started and stopped in a matter of seconds when warm and are about as tolerant to changes in load as diesel or gasoline internal combustion engines. The main reason they’re not used in modern power plants and vehicles is cost – about five times the price of an equivalently efficient and powerful steam turbine. One can also make more tolerant steam turbines at the cost of efficiency (somewhat compensated by the more tolerant turbines being cheaper).
Of course, if the source is coal (as opposed to nuclear), one can always gasify the coal and burn it in the very flexible and efficient gas turbine (which is more efficient and less polluting, as well as more flexible to the grid).
Another alternative is to use energy beyond what the grid can handle for manufacturing ammonia using water and air as feedstocks, replacing natural gas.
That said, we’re nowhere near reaching even that modest 20% level.
>I hope readers are beginning to understand [that up to 20% of grid generation from wind/solar can be reasonably accomodated, but above that grid stability becomes a problem.]
>That is the fact and renewables advocates have to accept it
Until you add storage.
We can use expensive methods such as flow batteries to provide small amounts of storage. They can help pay for their additional cost by replacing spinning (though not operating) reserves.
We can provide massive amounts of comparatively inexpensive storage by using thermal storage – which is suitable mainly for solar thermal. (I’ve already documented the feasibility of both solar thermal electricity and molten salt storage up thread so I’m not going to post links again. Scroll up if you missed them.)
It is more expensive than conventional sources; but solar thermal with storage is less expensive than photvoltatic without. It is interesting that without cash subsidy, solar thermal electric generators are providing peak power to California electric utilties on a commerical basis. California utilites are saving money by using these since they match peak load. and cost less than the natural gas generators currently used for peaking. Add 1.8 cents per kWh subsidy now available to new nuclear power plants in the U.S., and the capital subsidy also available[1] and you can pay for the cost of additional storage. – providing fully dispatchable energy – suitable for base, intermeidate, peaking and load following. So if you are going to keep saying the renewable energy for more that 20% of the grid is a fantasy, you are going to have to explain why solar thermal with storage cannot greatly exceed that percentage.
[1]http://www.ucsusa.org/assets/documents/clean_energy/SummaryoftheEnergyBill.pdf#search=%22Energy%20Policy%20Act%20of%202005%20nuclear%20subsidies%22
RE # 277
Yartrebo, you seem to be missing a very salient point regarding grid stability and renewables.
If a wind farm – say, 50 towers each 1.5 MW – goes off line for reasons of intolerable wind gusts, the grid will have to instantaneously make up the 75 MW of lost power. The wind generator operator contracts with standby generators, at a cost to wind customers, to kick in the alternative sources to make up the loss. Those sources are in a constant standby mode if they are paid to play that role otherwise the operator would have them in a shut down mode.
There appears to be adequate standby peaking equipment available to the grid in these autumn months but not as much so in the hot summer. If the peak demand increases in a control area there would be reason to add new peakers because their payback looks good. Gas turbines are still first choice because gas contracts are still easy to acquire.
There is no advantage for a private power generator to build standby for renewables and I have no doubt a public utility commission would NOT grant a rate increase for a regulated utility to build the standby for renewables.
I see your comment as an idea but not a business plan.
A problem that has been noted in this discussion is technical difficulties with the existing electrical grid’s ability to integrate renewable electricity generation — e.g. wind turbines and photovoltaics — particularly distributed and variable renewable electricity generation. The existing grid was and is designed to distribute power from large, centralized electricity generators such as coal, gas and uranium fired power plants and large hydropower plants. Only recently have state-level “net metering” laws required utilities to integrate power produced by small-scale renewable generation, e.g. residential photovoltaics.
I believe what is needed is a next-generation “smart grid” that is designed, or re-designed, to handle distributed, variable, small-scale electrical generation — an electricity “internet”.
Al Gore addressed this issue in his September 18 speech at New York University on steps that can be taken now to address the global warming crisis:
I think this is a crucial component of the path forward.
On Nov 4th There is and international day of action on climate change.
Events kick of 12pm outside the US embassy in grosvenor square.
For a timetable of the day visit the campaign against climate change website.
http://www.campaigncc.org
For a list of the countries involved so far visit the global climate campaign.
http://www.globalclimatecampaign.org
RE # 280
SecularAnimist, any informed person with knowledge of the facts regarding global average temperature increase, Arctic sea ice and glacial melt, etc., etc. will salute Vice President Gore’s challenge to rewire the US electric grid, plow more acres to grow ethanol feedstock, commit land to build wind and solar….and add your favorites here.
My trouble with VP Gore, you, Amory, Jeremy Rivkin and others with long lists of solutions is fundamental. But, I heartedly agree their proposals would make this world a cleaner, less strip mined planet. That said, my problem is none of those persons, and you, ever tell the audience how expensive these proposals are and how they can be financed.
AGW is the bill we are handing our children and grand children for the marvelous ride we have had on the post-industrial revolution rocket.
Debt is the other bill we hand off to our offspring.
Monthly payments to the institutions that rent our homes to us (a non-spam way of saying the M-word), personal magic card (non-spam) and federal debt total about $13 trillion or slightly more than total US GDP. Add the near $46 trillion the US gov will borrow to pay entitlements (SS, medicare, medicade, more debt service) and you begin to see how UNCLE does not, will not have two boards to rub together to underwrite much more than energy R&D programs.
Take a moment and reflect on how electic utility deregulation turned about half of our once-regulated utility industry over to WS (non-spam for that place in downtown NYC) traders and investors. How will the private sector decide it is in their short term (day-trading) interest to float tens of billions of dollars of bonds and equity to rewire the US grid to make it smart — put aside the need to just add more wire to make it reliable.
Ethanol floats on the lobbying strength of ADMand the Iowa politicians and voters. Congress members feed ethanol its subsidies out of sheer ambition — not common sense. What will an ice-free Arctic mean to temp and precip in the western North American grain-growing states in mid century?
Ideas are not business plans and without capital to invest (hundreds of billions) they are words on paper. ****side note**** beware inflation rate increases; they will wipe out the US taxpayer.
My wife keeps telling me the world needs hope to begin to get a handle on AGW. I agree. It also needs about a trillion dollars investors will hand over to (some speculative) plans to reconfigure the developed worlds electricity grid, transportation infrastructure and cruise line/pleasure flying industry DURING THE NEXT THREE DECADES.
Adaptation is not a dirty word and I am highly critical of VP Gore’s dismissal of adaptation as a diversion from his vision to replace our everything with his everythings.
The developed world has to do both and the developing world has a right to demand we help them adapt. That last item – alone – will max out your account.
[Response: Injecting sulphates is obviously not an ideal solution – in fact its probably a bad idea unless you’re really desperate. But it may not be quite so bad for acid rain as you think – in the stratosphere the fall-out would be much slower (I’m guessing) – William]
The rate of fallout is the same as the rate of injection. I’ve seen studies suggesting 5-10 million tons of sulfate aerosols will be needed. Spread over the entire planet, this isn’t that big of a deal by itself. It’s simply like adding another US to the planet. However, this will probably occur when the nations of the world have ramped up their coal use and acid rain is a huge problem anyway. This is especially true considering the EPA’s current numbers on acid rain and the acidification of the ocean. Then there is this little thing called China that is growing at very high speeds. Lets not forget the people at the oildrum who are saying energy is going to get expensive and pollution controls will likely take a hit if they are right. So adding another artificial US to the equation doesn’t seem like a great idea to me. Sulfate’s certainly are better than rising sea levels, but it’s not a panacea. I have the utmost respect for you William, but I’d have to see some raw numbers before I can believe it’s “not quite so bad”.
RE # 283
You said: [Then there is this little thing called China that is growing at very high speeds.] I understand the sentiment within which you used the phrase.
It would help readers to know that China emitted about 26 million tons of SO2 in 2005 and no end in sight. That is like adding nearly three USs to the planet without much improvement in the radiative forcings department. How much is enough and does any sulfate injection have anything to do with slowing the acidification of the oceans? Nope.
RE: 283 and 284. The fallout of sulfate aerosol from the stratosphere would take much longer than from the troposphere. Most of the sulfur dioxide gas emitted from coal fired power stations rains out in a few days to weeks as sulfuric acid or ammonium sulfate depending on the location, while that from sulfur dioxide in the stratosphere either from volcanic eruptions, from jet fuel exhaust or a hypothetical deliberate injection strategy takes 1-2 years.
The quantities needed to offset given levels of current and future forcings can be calculated. My own estimates required 0.572 Tg S injected into the stratosphere per year in 2010 rising to 2.65 Tg sulfur in 2050 to hold forcing at the 2000 level. One teragram is one million metric tons. This is far less than present day industrial emissions. Also, since flue gas desulfurization technology will eventually be installed on Chinese power plants, their total emissions, like those from the U.S. will decline over the coming decades.
While it is true that attempting to cool the troposphere with aerosol injections does nothing to reverse or slow down the acidification of the surface waters of the ocean, that acidification is almost entirely due to carbon dioxide. Sulfur oxides, either from industrial or aircraft emissions or a deliberate attempt to add them to the stratosphere will have little impact on ocean pH.
RE # 285
You said
[While it is true that attempting to cool the troposphere with aerosol injections does nothing to reverse or slow down the acidification of the surface waters of the ocean, that acidification is almost entirely due to carbon dioxide. Sulfur oxides, either from industrial or aircraft emissions or a deliberate attempt to add them to the stratosphere will have little impact on ocean pH.]
That was my point. Injecting sulphates into the wherever does nothing to diminish the acidification of the oceans. I realize the sulphates would not be a major contributor — simply an attempt (with gareat risk) to mask the problem of increasing atmospheric CO2 concentrations.