Unforced Varations: Aug 2012

Once more with feeling…

571 comments on this post.
  1. MARodger:

    David Levitt @50
    From UK numbers, using coal to produce electricity emits 200gC/kWh. The figure for using natural gas is 110gC/kWh. I haven’t the actual ‘carbon intensity’ figures to hand, but 3:1 sounds way off.

  2. Unsettled Scientist:

    The Human Factor is an editorial in Nature Climate Change that highlights new research not on the human drivers of climate change but rather on the human response to it.

    “it is this realization that documenting the nature of the ‘problem’ is only the start of the challenge of resolving it that has led to an upsurge in interest from the social scientists who seek, among many other things, to understand peoples’ perceptions of climate change risks, what it will take to change behaviours, and the roles that science education and communication should play. At the same time, economists are trying to get to grips with the effectiveness of carbon trading as a mitigation strategy, how rich nations will help the developing world adapt, and indeed whether standard economic models will remain viable into the future. Meanwhile, politicians grapple with how to translate all of this into action, and how to sell often controversial policies to the people they represent.”

  3. EOttawa:

    In the abstract for the new paper “Patterns of CO2 variability from global satellite data” by Ruzmaikin et al



    I noticed this:

    “The first principal component is phase-shifted relative to the Southern Oscillation indicating a causative relationship between the atmospheric CO2 and the ENSO.”

    As a layperson without a science background I interpret that as saying that [increased] CO2 is affecting ENSO. Is that a correct interpretation?

  4. Mark Shapiro:

    Bob @ 39 and SecularAnimist @48,

    Our 2.9 KW rooftop PV system has been operating for over a month now. You can watch it produce, along with thousands of other public Enphase-inverter systems here:
    enphase.com/products/enlighten/ (Click on “view live sites”)

    Even our sub-optimal, retrofitted, flat-roof, Chicago-code-compliant, 14% efficient system provides about half of our electricity, at a modest profit.

    PV Price/performance improves every year. It’s already twice as good in Germany, which is further down the learning curve. The panels themselves are already under $1/WattP, so the two huge opportunities for cost reduction are: 1) building integration; 2) electrical integration (hint: PV produces low voltage DC, all electronics and LEDs use low-voltage DC). But even today, rooftop PV for new construction is a no-brainer.

    We get a modest, positive financial return (all tax-free!) from the panels every month, even before the state and federal subsidies. BUT: PV has reduced our hidden subsidy from fossil fuel externalities. Those, of course, are huge, and climate is only one of them.

  5. deconvoluter:

    Re : #46
    Why, has Christopher Monckton been awarded an honorary degree in engineering * for his contributions to this topic?
    * He has been active in spreading the fallacy:

    Absence of climate runaway => absence of much gain from feedbacks

  6. Mike S:

    Bobl, thanks for the response. Yes, the NREL report is for CSP and not PV. Still, if we could replace our energy needs by carpeting an area the size of Delaware, or even several times the size of Delaware, I don’t see why that’s a showstopper. We devote many times that much area for farming, pretty much the entire state of Maine is used for forestry, etc. I wonder how much space current fossil fuel energy production including mines, fracking, pipelines, tar sands, power plants, etc.? Would solar even consume more land (not to mention solar’s other environmental benefits)?

  7. caerbannog:

    I just noticed that Kevin C’s global-avg temperature python script was mentioned up-thread. I cannot recommend it highly enough as a teaching tool.

    I tweaked it just a bit to dump avg annual anomalies (instead of monthly anomalies) and compared the output to the NASA/GISS “meteorological stations” index – it tracks the NASA/GISS results very nicely, although it does produce a bit more warming than NASA/GISS – my guess is that sparser sampling in the SH leads to more empty grid-cells in the SH than in the NH, resulting in a bit of NH overweighting. (If that’s the case, then the grid-cell interpolation that skeptics like to complain about actually *lowers* global-warming estimates).

    But given the simplicity of the algorithm, it really is quite amazing how closely it replicates the results that the “pros” (that would be NASA/GISS) publish.

    Python code is *much* easier to hack/modify than compiled C/C++/whatever code, so Kevin C’s script looks to be an ideal teaching tool to turn students loose with.

    Python is available for Windows/OSX/Linux, so any student with access to a laptop/PC can run the script and plot up the results.

    If you replace the print loop at the end of the script (the last 3 lines of code) with the lines below, you’ll get annual anomalies in .CSV format that you can plot up in Excel/OpenOffice for direct comparison with the NASA/GISS results at http://data.giss.nasa.gov/gistemp/graphs_v3/Fig.A.txt.

    Note: the asterisks are there to preserve indentation levels (very important for proper python script operation) – replace all ‘*’ chars with spaces. (The post editor here eats leading spaces).

    #### BEGIN
    print “year”,”,”,”temp”
    for year in years:
    **for month in months:
    **print year,”,”, yearavg

    For convenience, here again is the link to Kevin C’s script: http://www.skepticalscience.com/watts_new_paper_critique.html (you’ll need scroll down to get to the code).

    So teachers, turn your students loose with the code and have them crunch the GHCN V3 data themselves. Have them compare their results with the results that the “pros” (NASA/GISS) produce. Have them compare rural vs. urban results and raw vs. adjusted results.

    And if their parents demand to see the code, then show ’em the code. ;)

  8. Unsettled Scientist:

    Harmen @38, thanks for the link to the EGU press conference video. I enjoyed it but am now depressed. I see no indication of a sober conversation happening soon in the general population.

  9. Thomas:

    Bobl @39,Secular A @48, Mark@53
    Your estimate of 65kilometer squared for a GW sounds a bit large. I’m assuming that wi
    thin five years, average PV panel (not solar thermal) will be about 20% efficient. That m
    eans it takes 5km**2 to obtain a nominal gigawatt. I’m assuming the deployment strategy c
    hanges, because the are cost of panels has dropped so much, and should be at or under $.5
    0 per watt in five years (at the manufacturer). Todays systems assume that panel area is
    expensive, and use eith, panel, tilt, or single of dual axis tracking to maximize the output per square meter of panel. That implies that panels (or mirrors) are spaced widely en
    ough to avoid shading issues. With cheap panels, you maximize output by completely coveri
    ng the ground with horizontal panels, so the watts per square meter of land can increase
    substantially. Add another factor of five for weather, plus nighttime, which is typical o
    f a good site, and you end up with about 25km**2 for an average output of a kilowatt.

    I’m not very sanguine about the prospects for large scale CSP thermal. It can’t compet
    e against cheap panels, and several projects have been modified from CSP to PV. CSP power
    should command a premium due to its dispachability, but because of that premium, I don’t
    expect it do provide much daytime power -except as needed to cover demand spikes. The on
    e area where CSP probably makes economic sense is combines process heat and power, where
    a colocated industrial process need low grade heat.

    Secular Animist. I find it sad that the residential installers have made so little pro
    gress in installed system cost per watt. Thats only a bit better than 20% better than I g
    ot a 2.4KW system almost three years ago. The German’s are reportedly doing installations
    at $2.24/watt without the tax subsidies (the FIT effects return, not system cost). We ha
    ve a long way to go. A big chunk of PV system cost lies in the so-called soft-cost area.
    Chief among these are customer acquistion and permitting/inspection costs. I think the fo
    rmer is nontrivial for residential installers, that cost for acquiring you as a customer
    has already been spent whether you sign up or not, I suspect that fact can be leveraged i
    nto a discount. The other way to go would be DIY -or at least hire roofers, and electrici
    ans to do the work. Forcing the industry down the cost curve is going to be essential. BT
    W, my system was speced at 55% of annual usage, but because of continuing efficiency pro
    gress at home, its now up to 82%.

  10. caerbannog:

    re: my previous post: you can shorten the code snippet a bit by ditching the imonth counter and using len(months).

    Also benchmarked one of the runs on my 5-year-old el-cheapo laptop:

    % time python ./ghcn-simple.py qcu.inv qcu.dat > testraw.csv

    real 1m4.097s
    user 0m58.836s
    sys 0m0.692s

    It crunched the entire GHCN data-set in just over a minute of wall-clock time!

    Python’s much faster than I thought it would be — guess I should put learning python on my todo list…

  11. flxible:

    David Levitt@50
    the ERA says 50% – I suspect he’s trying to say [spinning] it produces 30% as much “pollution”, being a “cleaner” burning energy source – which ignores the methane generation/leaks involved in it’s production and transport.

  12. J Bowers:

    49 Tom Adams — “The US state of North Carolina just banned the use of projections of sea level from planning for 4 years:”

    Ah, the politicians from Jaws do exist. But, if this is the standard of sanity in North Carolina, there won’t be any need to hire Robert Shaw to take Brody to the shark next time: the shark might eventually be able to swim to them instead.

  13. Bobl:

    Thomas @ 58,
    See my analysis in July,

    PV Reliable Baseload equivalent supply requires about 146 square km (Equatorial)for a Gigawatt @ 20% and even at 100% Efficiency this would only come down to about 30 square km per Baseload equivalent Gigawatt.

    There are simple limits to the energy input to the system that prevent it ever getting better than that, Energy Conservation sees to that.

  14. Pete Dunkelberg:

    “Your adrenaline is running. You’re pumped up,” Streeper said. “You could just see a wall of flames coming this way. Everything was on fire.”

    Fire in Oklahoma

  15. Patrick 027:

    Re 16 Chris Dudley – of course, that would block OLR and so would have some global warming effect (I don’t know how much, relative to CO2 capture – of course you likely weren’t seriously proposing this solution).

    Re 53 Mark Shapiro : 2) electrical integration (hint: PV produces low voltage DC, all electronics and LEDs use low-voltage DC). – maybe buildings with two electrical systems, connected by an inverter – Solar PV feeds into the DC and the inverter connects to that and the AC? Although, lower volatage would increase losses getting from point A to point B – would that be significant in a building?

    Re 55 Mike S (re Bobl) “how much space current fossil fuel energy production” Well, here’s how much consumption is using:
    ~ 510,000,000 km^2 (the whole thing)

    Re 41 Bobl – climate scientists, meteorologists, and oceanographers do/can use complex numbers – for studying fluid mechanics – waves (Rossby/vorticity, (inertia)-gravity/Kelvin), and things like Ekman spirals. Also, the temperature and heat flux over depth from a surface with cyclical forcing would be a bit like an Ekman spiral, I think.

    But when talking about equilibrium climate sensitivity – or transient response, for that matter, the forcing is not generally a cycle. Phasor diagrams aren’t really applicable unless you have a cyclical forcing, or decompose the forcing into a linear superposition of cyclical forcings. At least in so far as Charney feedbacks go, I don’t think you have much of an inertia in the sense that you can get in RLC circuits or mass-spring-damper systems, so there won’t be a resonance – response amplitude simply increases with cycle period until it approaches the equilibrium value for a constant forcing of the same amplitude (what may be refered to as inertia is the effect of heat capacity, which produces a lag between forcing and response, but it isn’t capable of making the climate oscillate in respone to a change in forcing like the transient response of an underdamped system. This is setting aside internal variability, which is a whole other series of comments – we can gloss over that for now by considering a climatic state as encompassing that variability (of all such unforced variability, the one that acts most like a cycle is the QBO. But it is not at all like a mass-spring-damper or RLC system – based on my own understanding, it is forced by some flux of wave action (fluxes of energy and momentum, or whatever analogue of those concepts is useful in this application), and the wave-mean interaction gives rise to a cycle which should go faster if the flux increases; the flux is either not cyclical or it’s cycles would only cause a change in the angular velocity of the QBO phasor. See Holton, “An Introduction to Dynamic Meteorology”, Ch 12 (from memory)).

    If you are considering all feedbacks, the feedbacks need to have units – radiative forcing is measured in W/m2 and climate response is measured in K – feedback is W/m2 per K. The equilibrium climate sensitivity is the negative inverse of the sum of all feedbacks – which is negative including the Planck response, unless you get into a runaway situation. To express feedback in a nondimensional way, you need to pick some baseline sensitivity, such as when only including the Planck response. Then, if the total feedback (including the Planck response) is negative (stable equilibrium) but smaller than the Planck feedback alone, the nondimensional feedback just defined is positive. This is often what is meant by the net feedback – either that the non-Planck feedbacks sum to some positive W/(m2*K) value, or that the nondimensional value as just defined is positive. Unstable climate requires the nondimensional value to go past 1/0 or be negative, or for the non-Planck feedbacks to be positive and exceed the Planck response in magnitude. This may/can/has/does happen in Snowball freeze-thaw hysteresis or H2O-vapor runaway, which are outside the range of conditions the Earth has usually experienced, so far as I know.

    See also http://www.realclimate.org/index.php/archives/2012/07/unforced-variations-july/comment-page-8/#comment-241456 for an example of how feedback works mathematically in climate (note this is a very simple model that uses parameters at least some of which (feedback, I’d guess maybe effective heat capacity) are actually the output of the more sophisticated climate models which are based on more fundamental physics and sub-grid scale parameterizations where necessary (which are not merely guess-work – see RC’s FAQ on climate models parts 1 and 2).

  16. Patrick 027:

    technically off topic, but

    ~ 200 W/m2, 10 % efficient (let’s be conservative; we can multiply later (technology gains, system losses installed and aging) – 20 W/m2,

    packing density 40 %, 8 W/m2 land;

    Global energy usage ~ 15 TW primary equivalent or something like that; if wrong use a scaling factor; that’s ~ 5 to 6 (being generous at the high end) TW electrical equivalent where applicable (won’t apply to all uses – cogeneration or high temperature heating));

    6 TW / 8 W/m2 ~ 0.75 T m^2 = 750,000 km^2.
    Global land area ~ 150 million km^2
    75 = 5*15
    0.5 % land area produces 6 TWe PV. if only spread over 1/3 of land area, 1.5 % of that; 1/10 of land area, 5 % of that. What is global roof area, anyway?

    Some places get more than 250 W/m2.

    U.S. ~ 3 TW primary, convert to 1 TWe (0.125 T m^2), distribute over 1/3 the land area (~ 3 million km2), get 4.17 %. Perhaps we could use the agricultural land that is going to be abadoned due to persistent drought (runoff (that not captured and evaporated in the process of washing) might be used to boost productivity on neighboring lands).

  17. Patrick 027:

    … of course there’s no need to get 100 % of our electricity from PV, and oops, forgot the subject was baseload, but see http://www.skepticalscience.com/renewable-energy-baseload-power-intermediate.htm (note the advanced level option)

  18. Patrick 027:

    4.17 % – ignoring sig.figs. float PV panels on reservoirs to reduce evaportion. other stuff said before. done.

  19. Steve Fish:

    Re- Comment by Bobl — 4 Aug 2012 @ 6:39 PM:

    You appear to be stuck in an absolutist black and white loop. Again- We currently can’t use PV for base load until storage and transmission solutions become practical. Meanwhile, when many commercial power plants run at 100% during the day but at only 20% at night, PV generation capacity is now practical for picking up the daytime load. For now let the power plants provide the base load. Just like wind, this reduction in fossil CO2 can be done piecemeal, one panel at a time in grid tied systems.

    Again- The area used for solar electricity generation is inconsequential. I remember a nifty graphic referenced on this (RC) site that showed a globe on which the tiny square of area from which the total world’s electricity could be generated by PV was shown. Did somebody save this? A distributed system that doesn’t require the smart grid or any fancy electronics can be started right now. Actually it already has, but this move needs a big push, and those spouting “area” and “base load” silliness need to look at reality. There is plenty of area for panels in cities where daytime power is needed so that base load generation is not a question yet, and when it is think dry rock geothermal.

    I have been deriving most of my electricity from the sun now for seven years, it is like magic! Steve

  20. Susan Anderson:

    Oh Dear Gussie, Monckton been awarded a s science degree?!! Can you imagine how he will be able to exploit that with the credulous?

    Comment numbers change, good idea to include the name as well.

    Dr. Hansen’s latest (Seth Borenstein) is headlining the AP feeds, but Pielke Jr. is included, doing his best to discredit. No surprises there. One copy here:


    I like his OpEd in WashingtonPost:

  21. Bobl:

    @ Steve Fish,
    Sorry to burst your balloon but Solar is a to-nowhere technology, it’s a bit player, while it can work in limited decentralised micro-generation instances, from a practical perspective you need much higher energy density. There are much better choices Biomass, Hydro, Geothermal, or nuclear (perhaps Thorium).

    PV Solar also has a very sort life, and maintenance costs are high, once again due to the huge dimensions of the infrastructure. This is more than likely why they get abandoned in favour of Diesel

    Idealistically I’m sure you’d like it to be, but it “Just ain’t so”, bank on a different technology.

    I wont comment on this topic further.

  22. David B. Benson:

    Thomas @33 — Simply drill two holes into an olivene formation. Even basalt will likely do. Pump CO2 (very hard pumping) down one hole and withdraw an equal volume of saline solution from the other. The carbonation reaction is exothermic and drilling deeper makes it go faster. n any case, continue until CO2 starts coming up in the saline solution. Then stop and drill anthoer pump-up hole some goodly distance around the circle centered on the pump-down hole.

    The is more than enough basalt here in the Columbia basalt formation (on top of which I sit) to store all the excess CO2 so far produced amd still have room for vastly more.

    This is fairly basic geochemistry about which the internet offers ample relevant readings.

  23. Thomas Lee Elifritz:

    Sorry to burst your balloon but Solar is a to-nowhere technology, it’s a bit player, while it can work in limited decentralised micro-generation instances, from a practical perspective you need much higher energy density.

    Because some guy named Bobl said so on some blog! You heard it here first!

    There are much better choices Biomass, Hydro, Geothermal, or nuclear (perhaps Thorium).

    Well that will work for everything, plenty of ‘energy density’ there, no need to perform any actual energy conversion right? No work at all!

    You got it all figured out Bobl, thanks for enlightening us physicists.

  24. Patrick 027:

    Re 68 Bobl –

    The nuclear v. solar was declared permanently OT, but I don’t have enough info on nuclear anyway (I have some opinions that I would stand by but they don’t concern the entirety of the issues) – but how about solar AND nuclear AND … vs coal, oil, gas. Solar is better than coal. If nuclear really is better than solar than it therefore must be better than coal, so that wouldn’t bother me. Maybe it’s better than coal regardless? Etc. An emissions tax would go along way toward resolving… etc.

    But anyway…

    Zweibel, Mason, Fthenakis “A Solar Grand Plan” http://web.chem.ucsb.edu/~feldwinn/greenworks/Readings/solar_grand_plan.pdf
    – updated here http://www.clca.columbia.edu/papers/sun&wind-1.pdf
    – such as:
    Fthenakis, Kim, Alsema “Emissions from Photovoltaic Life Cycles” http://pubs.acs.org/doi/abs/10.1021/es071763q
    Fthenakis, Kim “Land use and electricity generation: A life-cycle analysis” http://www.sciencedirect.com/science/article/pii/S1364032108001354
    Fthenakis, Kim “Life-cycle uses of water in U.S. electricity generation” http://www.sciencedirect.com/science/article/pii/S1364032110000638

    Jacobson and Delucchi “A Plan to Power 100 Percent of the Planet with Renewables” http://www.scientificamerican.com/article.cfm?id=a-path-to-sustainable-energy-by-2030
    – related: http://www.awec2010.com/public/presentations/jacobson_mark.pdf
    “Providing allglobalenergywithwind,water,andsolarpower,”… parts 1 and 2

    “Will we have enough materials for energy-significant PV production?”
    Wadia et al “Materials Availability Expands the Opportunity for Large-Scale Photovoltaics Deployment” http://pubs.acs.org/doi/abs/10.1021/es8019534, http://www.cyruswadia.com/prof/Publications_files/Wadia et.al. Materials Availability Expands the Opportunity for Large Scale PV.pdf

    (and with PV, there’s a general idea with many incarnations and future potential; right now we need to implement clean energy but continued R&D is also good for even better future technologies. See nanoparticles, sol-gel, titanium dioxide solar cells, CZTS and zinc phosphide, even pyrite!, organic solar cells, thermophotovoltaic, plasmonics, light trapping, (X)CPV)

    – Valentino et al http://www.dis.anl.gov/publications/windpower/es2038432.pdf
    and (I think this is the same as refered to in the skepticalscience blog) – Kubiszewski et al http://pdx.academia.edu/idakub/Papers/1180199/Meta-Analysis_of_Net_Energy_Return_for_Wind_Power_Systems

    and, again

    from a practical perspective you need much higher energy density.” Calculate the output from a lifetime of a solar cell, divide by mass – quite impressive! Area? See above (it’s potentially much better than biomass – but that doesn’t mean biomass is all bad; obviously some biomass energy options exist which would increase the overall efficiency of food production, others would not compete so much with crops, etc. Algae, used napkins, peanut shells, coffee grounds, olive pits, damaged and diseased crops…)

    PV Solar also has a very sort life, and maintenance costs are high, once again due to the huge dimensions of the infrastructure. This is more than likely why they get abandoned in favour of Diesel Something doesn’t sound quite right about maintenance costs, but that aside, you’re completely wrong on lifetime. It seems the standard LCA assumes something like 30 years. A warranty is important for an individual buyer, but from a fleet standpoint you’re concerned about how long the average device lasts, how the average device ages. PV panels generally could push 50 or 60 years or more. The land use efficiency will decline a bit but there’s give and take – whatever’s best, etc.

  25. MARodger:

    flexible @59
    That ERA link you give is interesting. It shows the US figures for CO2/kWh that when I convert into my units are substantially higher than the UK figures but with a reasonably similar ratio between gas & coal. Gas US 138gC/kWh UK 110gC/kWh. Coal US 273gC/kWh UK 200gC/kWh. As the figure is for kWh delivered, the higher US figures may be due to the longer transmission distances in the US or other transmission system losses. The ratios (US 50% UK 55%) may be affected by the relative ages/efficiencies of the generating plant

  26. Hank Roberts:

    dual purpose panels — I’ve been waiting and am still waiting to see these show up for the ordinary user. Nothing on the local market yet.

    2012 overview: http://www.sciencedirect.com/science/article/pii/S1364032111006058
    “… hybrid photovoltaic/thermal (PV/T) collector systems. A major research and development work on the photovoltaic/thermal (PVT) hybrid technology has been done since last 30 years. Different types of solar thermal collector and new materials for PV cells have been developed for efficient solar energy utilization. The solar energy conversion into electricity and heat with a single device (called hybrid photovoltaic thermal (PV/T) collector) is a good advancement for future energy demand. This review presents the trend of research and development of technological advancement in photovoltaic thermal (PV/T) solar collectors and its useful applications like as solar heating, water desalination, solar greenhouse, solar still, photovoltaic–thermal solar heat pump/air-conditioning system, building integrated photovoltaic/thermal (BIPVT) and solar power co-generation.”

    Yeah, the abstract reads like nobody bothered to help the author with English; we can hope the engineering was better than the drafting.

  27. Ray Ladbury:

    You know, any time I see a poster who contends that a particular energy source is “the answer” or who dismisses a technology that is rapidly advancing, and which has some very desirable characteristics, I feel quite justified in pretty much ignoring anything he says on any other topic. I mean, he might be an idiot-savant, but he’s certainly an idiot.

  28. Steve Fish:

    Re- Comment by Bobl — 4 Aug 2012 @ 8:56 PM:

    You are revealing yourself with your deliberately incorrect statements.

    Just for fun let’s take your first choice, biomass. You think that PV panels have low energy density, well the energy efficiency of photosynthesis in most plants (you know- biomass) is much worse than PV at 1% to 2%, and it requires a lot of processing and moving about before it is useful. Do you know of anyone who is proposing to generate electricity, in competition with PV, on a large scale?

    Get serious, Steve

  29. Steve Fish:

    Correction to my 5 Aug 2012 @ 9:50 AM-

    Do you know of anyone who is proposing to generate electricity WITH BIOMASS, in competition with PV, on a large scale?

  30. SecularAnimist:

    Mike S wrote: “Still, if we could replace our energy needs by carpeting an area the size of Delaware”

    Interesting that you should mention Delaware, because its next-door neighbor New Jersey is the second largest solar market in the USA. PV is being installed all over that densely developed state. According to the New Jersey governor’s office:

    New Jersey installed more solar capacity in the first quarter of 2012 than any other state, and led the nation in solar installations on commercial and industrial properties in 2011. There are over 16,000 solar installations on homes, offices, schools, and hospitals throughout the state. The state currently has over 800 MW in installed capacity and another 600 MW of solar in various stages of installation. Of the electricity generated in New Jersey, over 1% now comes from solar energy … According to the Department of Energy, New Jersey has the 7th highest Renewable Energy Portfolio Standard in the nation at 22.5% by 2021.

    New Jersey’s Republican governor has just signed bipartisan legislation to increase the state’s already strong support for its solar industry, and to address land use concerns, while saving ratepayers millions of dollars:

    “… the law will save ratepayers approximately $1.076 billion over the next 15 years as compared to the current solar subsidy schedule … consistent with the Christie Administration’s objective of promoting dual-benefit net-metered projects and discouraging large-scale solar projects on farmland and open space; creates a sub-program to incent the development of solar projects on landfills and brownfields; and lowers costs for participating schools and government entities through net-metering aggregation.

    The incentives to develop utility-scale solar on top of landfills and brownfields are very important. There is a lot of degraded, otherwise unused (or even otherwise unusable) land in and around urban areas where PV can be deployed — close to existing grid infrastructure and close to the point of use.

    So, “carpeting an area the size of Delaware”? No. Carpet all the commercial and industrial and residential rooftops, parking lots, landfills, brownfields, etc. in Delaware. And New Jersey. And then you are getting somewhere.

    And remember, these are far from the sunniest locations in the USA. Look at what New Jersey and Germany are doing with only a modest solar energy resource to harvest, and then imagine their policies applied to the sunniest regions of America.

  31. Hank Roberts:

    > solar … micro … s[h]ort life … maintenance …

    ya think these folks will be coming back to swap out for diesels?

    (Sierra Club Solar Homes Campaign currently in Arizona, California, Colorado, Maryland, Massachusetts and New York.)

  32. SecularAnimist:

    Bobl wrote: “PV Solar also has a very sort life, and maintenance costs are high, once again due to the huge dimensions of the infrastructure.”

    With all due respect, both of those statements are just false.

    For example, Suntech’s PV panels, typical of the mass market silicon panels being sold today, have a 10-year “repair, replacement or refund” warranty for manufacturing defects, and a performance warranty that guarantees the panels will produce at least 90 percent of their nominal output for 12 years, and 80 percent of nominal output for 25 years. Enphase micro-inverters have a 15 year manufacturer’s warranty.

    These are significantly longer warranties than one usually gets with comparably expensive residential technology, for example gas furnaces and electric heat pumps typically have only 5 or 10 year warranties.

    As to “maintenance costs”, rooftop PV requires little or no maintenance (or any user intervention at all, in typical grid-tied residential systems) so those costs are typically near zero — and again, are certainly far less than the typical costs of maintaining an HVAC system.

    I would just add that focusing on whether, when or at what cost solar can duplicate the baseload role of coal or nuclear power plants is beside the point. Solar is inherently peak-matching power, that can provide much, and in some cases all, of the consumer’s peak electricity demand. As far as the grid is concerned, distributed solar “looks like” demand reduction — and to some extent, with grid-tied net-metered systems that produce a surplus of power that can be fed into the grid, it “looks like” peak-matching power that naturally comes online when it is most needed. This reduces the need for large baseload power plants.

  33. Whit:

    The refutation of Einstein by his German contemporaries is that he was doing “Jewish science” – that his results were motivated by a desire to confound the true German way. Similarly, the opponents of the results promoted in places like this blog point out that it is “Social_ist science” – results motivated by a desire to confound the true Exxon way.

    Can we admit this? That relativity and climate science are wrong, if wrong, for closely similar reasons?

  34. B A Carter:

    Re: David B Benson, 69. I presume you are thinking in terms of something like serpentinisation. I see two problems. Firstly olivine bearing rocks are dense and of low permeability, there will be mechanical problems in getting your CO2 into the rock, meaning that the reaction rates will be low. Much more important, though, is the nature of the changes in the rock. Olivine has a density of about 3.3 kgm3, serpentine has a density of about 2.7 kgm3 so you are looking at a volume increase sufficient to generate earthquakes. Note also that some serpentine producing reactions have methane as one of the end products.

  35. Jim Larsen:

    39 Bobl said “intense radiation fields”

    Uh, care to explain that?

    48 SecularA said, “after available tax credits…plus $1,014 from the state…Sounds good to me”

    Yes, having other people give you free money might sound good to you, but on a science site that’s irrelevant, isn’t it? You have to include all costs paid by all people. Otherwise, you’re just feeding at the trough and pretending nobody else has to provide the food.

    Using your logic (though in an opposite way), apartment dwellers should buy a micro-hydro system to attach to their kitchen sink and run the water full blast 24/7. Free electricity!

    How much is the system’s full-price fully-financed cost per KWH and what is your local rate? Won’t be a perfect comparison because of externalities, but it’s the place to start. A thumbnail – perhaps $20k cost, $500/yr benefit for 30 years = $15k, so even without interest you’re wasting $5k.

    Your major point is completely right, of course. There’s plenty of roof and other space just waiting for solar. We don’t have to give up the glorious state of Delaware.

  36. B A Carter:

    Sorry for screwing up the density units in No 81 – I was in a hurry! It should of course be gcm3 or equivalent.

  37. Steve Fish:

    It seems to me that there has been a recent and abrupt increase in very inept trolling behavior here. It is always interesting when extreme short term events like this occur. It could be that this is just a glitch in the trolling weather and, perhaps, the big kids might just be away on summer vacation and they let the junior string try to show their stuff while they are gone. On the other hand, if enough of these extreme poor quality events continue to happen with more frequency than in the past, we could be seeing a real downturn in the trolling climate. I am not one of those people who claim that the trolling climate has been flat for the last ten years, but I also understand that attribution will require more time before the climate signal can be statistically differentiated from the noise. A statistical analysis of the dates of Bore Hole posts could be a valuable contribution. Steve

  38. Pete Dunkelberg:

    You think CO2 is plant food? This is plant food. How can the corn crop be in trouble with so much plant food laying around free for the asking?

  39. Patrick 027:

    Re my 71 Re 68 Bobl –

    Re 73 Hank Roberts – yes! I remembered that after I posted the comment; PV cogeneration should generally improve electrical output by cooling the cells and reduce the combined area needed for electricity and heat.

    On top of that, roofs not otherwise suitable for PV (local climate, also shade from trees), could still have solar water heating, for that matter daylighting. Passive solar and other energy efficiency, etc.

    Regarding LCA’s – http://thinkprogress.org/climate/2009/04/29/204025/csp-concentrating-solar-power-heller-water-use/

    Regarding my potential technologies list, I forgot: luminescent concentrators (can use diffuse radiation, can be made into windows too (maybe use UV and solar IR and let visible light through) (can be stacked analogously to multijunction cells), hot carrier technology, electrochemical cells – etc. There’s also this kind of thing:

    “Electricity and Carbon Dioxide Used to Generate Alternative Fuel”

    Stuart Licht et al “A New Solar Carbon Capture Process: Solar Thermal Electrochemical Photo (STEP) Carbon Capture”
    http://www.flintbox.com/public/filedownload/3226/09-00x Licht Carbon Capture Article

    interesting (requires energy to get Li presumably, but you get a semiconductor out of it)

    “New Cement-Making Method Could Slash Carbon Emissions
    The proof-of-concept device concentrates sunlight to break apart limestone.”

    (and parabolic trough collectors are sufficient for a lot of industrial heating needs (see “Cool Energy” – a book – although the one I have is probably at least somewhat out of date by now))

    (and there’s interesting biomass ideas too – I think I read something once about bacteria converting – sugar? – to electrical energy.)

  40. Eli Rabett:

    FWIW iron fertilization may offer the highest leverage.

  41. Eli Rabett:

    Eli had a long talk with Klaus Lackner at a conference a couple of years ago. FWIW while the chemistry is interesting, it looks pretty far away from implementation on a large scale, the question of what to do with the CO2 is open and set up costs will not be zero if there is to be any measurable effect.

  42. Patrick 027:

    Re Chris Dudley @ 16 – 400 ppm implies a partial pressure ~ 40 Pa near sea level. From http://en.wikipedia.org/wiki/Carbon_dioxide_data#Vapor_pressure_of_solid_and_liquid, saturation vapor pressure at -50 deg C is 683.4 kPa; it looks like you have to get down near ~-138 deg C (~135 K) to get it down around ~40 Pa.

    (subarctic winter, clear sky, looking up from 3 km altitude,
    ground temperature offsect, K; W/m^2, brightness temperature (full spectrum) in K

    -50: 56.2374, 177.46
    -60: 48.7014, 171.19
    -70: 41.762, 164.74
    -75: 38.5278, 161.45
    -80: 35.4506, 158.13

    I couldn’t get a realistic temperature profile but I got the 3 km T close to the coldest surface temperature with much of the troposphere being unreasonably cold, still couldn’t get below 140 K brightness temperature (and at 3 km you’d need to get colder still without pressurizing).

    Of course, if you put CO2 inside a box which is reflective except for those wavelengths where the atmosphere is more nearly transparent, you could get closer to absolute zero provided thermal insulation from immediate surroundings. Alternatively, pressurize the air (heat it up, emit OLR, freeze CO2 – recover some of the energy as the remaining gas expands, etc.).

  43. David B. Benson:

    B A Carter @84 — Since there are now at least two interested in natural carbonization of minerals here are some references:

    In situ peridotite weathering:

    In situ basalt weathering:

    Ex situ olivine weathering:

    See references 7, 8 and 9 in

    Mine tailings:

    Your knowledge about these geologic processes seems currently not sufficiently thorough as to be able to avoid erroneous conclusions. I stand by the claim that basalt/olivine/periodotite weathering is practially feasible. [Obviously doind a pilot study first would be the next step forward; all that is lacking is the will.]

  44. Patrick 027:

    Re 39 Bobl – yes, intense radiation fields – you double it near the mirrors in the sense that you have the downward solar flux plus it’s reflection. On the other hand if you don’t have the mirrors you’d have ground emitting LW radiation, although that’s considerably smaller during peak insolation (larger on average, though) …

    – and you’d want the mirrors to emit thermal radiation anyway because otherwise you’re reducing OLR (but not that much compared to anthropogenic CO2 – example: 150 W/m2 average direct insolation – assuming conversion efficiency similar to fossil fuels and nuclear, a reduction in OLR of ~ 300 W/m2 would still have a very very very very small global average effect as it would be double the direct heating from the supply of the same amount of energy from combustion and fission (15 TW ~= 0.03 W/m2, so this would be 0.06 W/m2 – and it wouldn’t keep growing from constant usage) – and it wouldn’t be that large a forcing anyway because it would reflect downward LW radiation from the atmosphere back up – the big difference would be in the atmospheric window – and even in that, tilted mirrors would inevitably be reflecting some ground-emitted radiation from the mirrored side and might be emitting from the back side, so… – and maybe the kinds of mirrors often used have large emissivities in LW for all I know – on the other hand, localized cooling from the continued LW cooling and the export of some fraction of insolation, depending on changes in evapotranspiration, ??might concievably reduce low-level cloud cover via sinking air??).

    … so it would be like being in the bright sun on top of snow, and you can get sunburned that way, but how long is a bird going to fly around there (and feathers would block some radiation, I’d think)? The really intense radiation is near where the mirrors focus.

    By the way, CSP can easily have storage. I think there are project(s) planned or being built with that. CSP baseload is totally doable.

  45. Patrick 027:

    Re 85 Jim Larsen – I completely agree that full costs must be considered; it makes sense to consider the compensation of tax credits etc. in terms of how they compare to the effect of a justifiable emissions tax on competing sources such as coal.

  46. sidd:

    Prof. Box has been busy

    GRIS is


    “… little doubt that recent summer air temperatures for Greenland ice are the highest in at least 172 years …”

    “… the recent summer temperatures are ~0.5 C higher in absolute magnitude than those in the 20th century.”

    2)still dark

    “Late July’s reflectivity remains below other years in the observational record since 2000 and the values are trending lower again because of the darkening effect of near-surface air temperatures reported for 24-31 July being near or above the melting point …”


  47. Patrick 027:

    Re my CSP comments – importantly, mirrors will reflect diffuse light, some of which will go up and not be backscattered; thus a cooling effect. (On a cloudy day, the reflection from CSP would brighten the base of the clouds and this could enhance flat-panel solar energy performance nearby – signicantly? I don’t know.)

  48. Patrick 027:

    Re 84 B A Carter re David B. Benson –
    CH4 production, if of the same C as the CO2 input, could be used for energy without a net Additional emission. I suppose cutting spaces in the rocks for them to expand would partially defeat the benifits of in situ.

    Although that reminds me of a rather outlandish sci-fi sounding idea for CSP – a very large centralized CSP plant using several cubic km of rock in the ground for heat storage, with water used to bring heat down and up – mine the return flow for mineral resources, and then decommision the plant in 1000 to 1000000 years (I have no idea how long it would take) and mine all the anthropogenic ores and pretty crystals that were created by the hydrothermal activity.

    Anyway, I’m rather hopeful about these sequestration ideas not because we could then continue using fossil fuels but because we might have some hope of returning the Earth to what I grew up (minus the semi-irreversable sea level rise) with after fossil fuel usage slows to a trickle.

  49. David B. Benson:

    Patrick 027 @98 — There is no need to further fracture the rock. The expansion due to weathering will do that quite nicely.

  50. Patrick 027:

    Re 99 David B. Benson – I meant to reduce the earthquake risk, if there is one…(?) I haven’t had time to look at those links yet. (Interestingly, since the in situ is ‘self-fracking’, I guess that may be more benign than regular fracking – no nasty chemicals getting into the water supply, presumably?)