NewEnergyNews: TODAY’S STUDY: 100 MEGAWATT POWER PLANTS FROM THE OCEAN’S TEMPERATURE GRADIENT

NewEnergyNews

Gleanings from the web and the world, condensed for convenience, illustrated for enlightenment, arranged for impact...

The challenge: To make every day Earth Day.

YESTERDAY

  • LABOR DAY STUDY: CHINA NEW ENERGY MOVES AHEAD
  • NO QUICK NEWS TODAY. BACK TOMORROW.
  • THE DAY BEFORE

  • Weekend Video: The Economic Opportunity In The Climate Fight
  • Weekend Video: The Future Of Energy
  • Weekend Video: Advances In BioEnergy
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    GET THE DAILY HEADLINES EMAIL: CLICK HERE TO SUBMIT YOUR EMAIL ADDRESS OR SEND YOUR EMAIL ADDRESS TO: herman@NewEnergyNews.net

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    THE DAY BEFORE THE DAY BEFORE

  • FRIDAY WORLD HEADLINE-CLIMATE CHANGE – IT GETS WORSE
  • FRIDAY WORLD HEADLINE-WHERE AND HOW WIND IS GROWING IN THE WORLD
  • FRIDAY WORLD HEADLINE-CHINA TO LEAD SOLAR MARKET GROWTH DESPITE OBSTACLES
  • FRIDAY WORLD HEADLINE-THE ENORMOUS POTENTIAL OF WORLD GEOTHERMAL
  • THE DAY BEFORE THAT

    THINGS-TO-THINK-ABOUT THURSDAY, August 28:

  • TTTA Thursday-PRESIDENT TO TAKE ACTION ON CLIMATE
  • TTTA Thursday-BIRDS AND ENERGY, THE BIGGER STORY
  • TTTA Thursday-NEW CA LAW STREAMLINES SOLAR PERMITTING
  • TTTA Thursday-DATA CENTER EFFICIENCIES CAN SAVE U.S. $3.8BIL/YR
  • AND THE DAY BEFORE THAT

  • THE STUDY: THE RISKIEST ENERGY IN THE WORLD
  • QUICK NEWS, August 27: VERIZON’S $40MIL SOLAR BUY; WIND PRICES HIT RECORD LOWS; NUKE INSPECTOR SAYS DIABLO CYN IS UNSAFE
  • THE LAST DAY UP HERE

  • THE STUDY: U.S. WIND RIGHT NOW
  • QUICK NEWS, August 26: CLIMATE MODELS PROVE RIGHT AGAIN; ABOUT INVESTING IN SOLAR; GM VS TESLA IN THE 200 MILE RACE -

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    Anne B. Butterfield of Daily Camera and Huffington Post, is a biweekly contributor to NewEnergyNews

  • Another Tipping Point: US Coal Supply Decline So Real Even West Virginia Concurs (REPORT)

    November 26, 2013 (Huffington Post via NewEnergyNews)

    Everywhere we turn, environmental news is filled with horrid developments and glimpses of irreversible tipping points.

    Just a handful of examples are breathtaking: Scientists have dared to pinpoint the years at which locations around the world may reach runaway heat, and in the northern hemisphere it's well in sight for our children: 2047. Survivors of Superstorm Sandy are packing up as costs of repair and insurance go out of reach, one threat that climate science has long predicted. Or we could simply talk about the plight of bees and the potential impact on food supplies. Surprising no one who explores the Pacific Ocean, sailor Ivan MacFadyen described long a journey dubbed The Ocean is Broken, in which he saw vast expanses of trash and almost no wildlife save for a whale struggling a with giant tumor on its head, evoking the tons of radioactive water coming daily from Fukushima's lamed nuclear power center. Rampaging fishing methods and ocean acidification are now reported as causing the overpopulation of jellyfish that have jammed the intakes of nuclear plants around the world. Yet the shutting down of nuclear plants is a trifling setback compared with the doom that can result in coming days at Fukushima in the delicate job to extract bent and spent fuel rods from a ruined storage tank, a project dubbed "radioactive pick up sticks."

    With all these horrors to ponder you wouldn't expect to hear that you should also worry about the United States running out of coal. But you would be wrong, says Leslie Glustrom, founder and research director for Clean Energy Action. Her contention is that we've passed the peak in our nation's legendary supply of coal that powers over one-third of our grid capacity. This grim news is faithfully spelled out in three reports, with the complete story told in Warning: Faulty Reporting of US Coal Reserves (pdf). (Disclosure: I serve on CEA's board and have known the author for years.)

    Glustrom's research presents a sea change in how we should understand our energy challenges, or experience grim consequences. It's not only about toxic and heat-trapping emissions anymore; it's also about having enough energy generation to run big cities and regions that now rely on coal. Glustrom worries openly about how commerce will go on in many regions in 2025 if they don't plan their energy futures right.

    2013-11-05-FigureES4_FULL.jpgclick to enlarge

    Scrutinizing data for prices on delivered coal nationwide, Glustrom's new report establishes that coal's price has risen nearly 8 percent annually for eight years, roughly doubling, due mostly to thinner, deeper coal seams plus costlier diesel transport expenses. Higher coal prices in a time of "cheap" natural gas and affordable renewables means coal companies are lamed by low or no profits, as they hold debt levels that dwarf their market value and carry very high interest rates.

    2013-11-05-Table_ES2_FULL.jpgclick to enlarge

    2013-11-05-Figure_ES2_FULL.jpg

    One leading coal company, Patriot, filed for bankruptcy last year; many others are also struggling under bankruptcy watch and not eager to upgrade equipment for the tougher mining ahead. Add to this the bizarre event this fall of a coal lease failing to sell in Wyoming's Powder River Basin, the "Fort Knox" of the nation's coal supply, with some pundits agreeing this portends a tightening of the nation's coal supply, not to mention the array of researchers cited in the report. Indeed, at the mid point of 2013, only 488 millions tons of coal were produced in the U.S.; unless a major catch up happens by year-end, 2013 may be as low in production as 1993.

    Coal may exist in large quantities geologically, but economically, it's getting out of reach, as confirmed by US Geological Survey in studies indicating that less than 20 percent of US coal formations are economically recoverable, as explored in the CEA report. To Glustrom, that number plus others translate to 10 to 20 years more of burning coal in the US. It takes capital, accessible coal with good heat content and favorable market conditions to assure that mining companies will stay in business. She has observed a classic disconnect between camps of professionals in which geologists tend to assume money is "infinite" and financial analysts tend to assume that available coal is "infinite." Both biases are faulty and together they court disaster, and "it is only by combining thoughtful estimates of available coal and available money that our country can come to a realistic estimate of the amount of US coal that can be mined at a profit." This brings us back to her main and rather simple point: "If the companies cannot make a profit by mining coal they won't be mining for long."

    No one is more emphatic than Glustrom herself that she cannot predict the future, but she presents trend lines that are robust and confirmed assertively by the editorial board at West Virginia Gazette:

    Although Clean Energy Action is a "green" nonprofit opposed to fossil fuels, this study contains many hard economic facts. As we've said before, West Virginia's leaders should lower their protests about pollution controls, and instead launch intelligent planning for the profound shift that is occurring in the Mountain State's economy.

    The report "Warning, Faulty Reporting of US Coal Reserves" and its companion reports belong in the hands of energy and climate policy makers, investors, bankers, and rate payer watchdog groups, so that states can plan for, rather than react to, a future with sea change risk factors.

    [Clean Energy Action is fundraising to support the dissemination of this report through December 11. Contribute here.]

    It bears mentioning that even China is enacting a "peak coal" mentality, with Shanghai declaring that it will completely ban coal burning in 2017 with intent to close down hundreds of coal burning boilers and industrial furnaces, or shifting them to clean energy by 2015. And Citi Research, in "The Unimaginable: Peak Coal in China," took a look at all forms of energy production in China and figured that demand for coal will flatten or peak by 2020 and those "coal exporting countries that have been counting on strong future coal demand could be most at risk." Include US coal producers in that group of exporters.

    Our world is undergoing many sorts of change and upheaval. We in the industrialized world have spent about a century dismissing ocean trash, overfishing, pesticides, nuclear hazard, and oil and coal burning with a shrug of, "Hey it's fine, nature can manage it." Now we're surrounded by impacts of industrial-grade consumption, including depletion of critical resources and tipping points of many kinds. It is not enough to think of only ourselves and plan for strictly our own survival or convenience. The threat to animals everywhere, indeed to whole systems of the living, is the grief-filled backdrop of our times. It's "all hands on deck" at this point of human voyaging, and in our nation's capital, we certainly don't have that. Towns, states and regions need to plan fiercely and follow through. And a fine example is Boulder Colorado's recent victory to keep on track for clean energy by separating from its electric utility that makes 59 percent of its power from coal.

    Clean Energy Action is disseminating "Warning: Faulty Reporting of US Coal Reserves" for free to all manner of relevant professionals who should be concerned about long range trends which now include the supply risks of coal, and is supporting that outreach through a fundraising campaign.

    [Clean Energy Action is fundraising to support the dissemination of this report through December 11. Contribute here.]

    Author's note: Want to support my work? Please "fan" me at Huffpost Denver, here (http://www.huffingtonpost.com/anne-butterfield). Thanks.

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    Anne's previous NewEnergyNews columns:

  • Another Tipping Point: US Coal Supply Decline So Real Even West Virginia Concurs (REPORT), November 26, 2013
  • SOLAR FOR ME BUT NOT FOR THEE ~ Xcel's Push to Undermine Rooftop Solar, September 20, 2013
  • NEW BILLS AND NEW BIRDS in Colorado's recent session, May 20, 2013
  • Lies, damned lies and politicians (October 8, 2012)
  • Colorado's Elegant Solution to Fracking (April 23, 2012)
  • Shale Gas: From Geologic Bubble to Economic Bubble (March 15, 2012)
  • Taken for granted no more (February 5, 2012)
  • The Republican clown car circus (January 6, 2012)
  • Twenty-Somethings of Colorado With Skin in the Game (November 22, 2011)
  • Occupy, Xcel, and the Mother of All Cliffs (October 31, 2011)
  • Boulder Can Own Its Power With Distributed Generation (June 7, 2011)
  • The Plunging Cost of Renewables and Boulder's Energy Future (April 19, 2011)
  • Paddling Down the River Denial (January 12, 2011)
  • The Fox (News) That Jumped the Shark (December 16, 2010)
  • Click here for an archive of Butterfield columns

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    Some details about NewEnergyNews and the man behind the curtain: Herman K. Trabish, Agua Dulce, CA., Doctor with my hands, Writer with my head, Student of New Energy and Human Experience with my heart

    email: herman@NewEnergyNews.net

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    Your intrepid reporter

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      A tip of the NewEnergyNews cap to Phillip Garcia for crucial assistance in the design implementation of this site. Thanks, Phillip.

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    Pay a visit to the HARRY BOYKOFF page at Basketball Reference, sponsored by NewEnergyNews and Oil In Their Blood.

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  • Wednesday, January 09, 2013

    TODAY’S STUDY: 100 MEGAWATT POWER PLANTS FROM THE OCEAN’S TEMPERATURE GRADIENT

    Modeling the Physical and Biochemical Influence of Ocean Thermal Energy Conversion Plant Discharges into their Adjacent Waters

    Pat Grandelli, et. al., 29 September 2012 (Makai Ocean Engineering)

    Executive Summary

    This paper describes the modeling work by Makai Ocean Engineering, Inc. to simulate the biochemical effects of of the nutrient-enhanced seawater plumes that are discharged by one or several 100 megawatt OTEC plants. The modeling is needed to properly design OTEC plants that can operate sustainably with acceptably low biological impact.

    Ocean Thermal Energy Conversion (OTEC) uses large flows of warm tropical seawater and cold deep seawater to generate non-polluting electric power. The magnitude of the global OTEC resource dwarfs that of other other marine renewable energy technologies, and OTEC power is non-intermittent, making it suitable for utilities and manufacturing. Small demonstration OTEC plants using commercially-available equipment have generated 50 - 270 kilowatts of electricity.

    Recent advances in offshore design and cold water pipe technologies have renewed interest in developing large 100 megawatt plants that would be cost-competive with local island utilities. Such plants would have several seawater pumps, each equivalent to tugboat engines, that would guide 750 tonnes per second of seawater thorugh the OTEC system.

    At most potential OTEC sites, the tropical ocean is thermally stratified into a well-mixed warm upper layer overlying cooler and denser seawater. This stratification hinders the supply of nutrients upwelled into the photic zone, which results in a nutrient-limited "oligotrophic" phytoplankton community having low biological productivity. Discharging deep seawater nutrients (primarily nitrates) into the upper waters from the OTEC plant could potentially enhance phytoplankton growth, shift community species composition, or cause algal blooms. It is desirable to discharge the seawater flows deep enough so that the discharged nutrients are diluted and remain below the photic zone. Thus, the size and depth of the large seawater ducts affect both the overall architecture of an OTEC plant as well as the extent of the perturbation to the ambient phytoplankton populations.

    In order to quantify the effect of discharge configuration and phytoplankton response, Makai Ocean Engineering implemented a biological and physical model for the waters surrounding O`ahu, Hawai`i, using the EPA-approved Environmental Fluid Dynamics Code (EFDC). Each EFDC grid cell was approximately 1 square kilometer by 20 meters deep, and used a time step of three hours. The biological model was set up to simulate the biochemical response for three classes of organisms: Picoplankton (< 2 um) such as prochlorococccus, nanoplankton (2-20 um), and microplankton (> 20 um) e.g., diatoms. The dynamic biological phytoplankton model was calibrated using chemical and biological data collected for the Hawaii Ocean Time Series (HOTS) project. Peer review of the biological modeling was performed by Dr. John Hamrick, the author of EFDC, and by Dr. Matt Church of the University of Hawai'i, a leading marine microbiologist.

    The physical oceanography model uses boundary conditions from a surrounding Hawai'I Regional Ocean Model, (ROM) operated by the University of Hawai`i and the National Atmospheric and Oceanic Administration. The ROM provided tides, basin scale circulation, mesoscale variability, and atmospheric forcing into the edges of the EFDC computational domain. This model is the most accurate and sophisticated Hawai'ian Regional Ocean Model presently available, assimilating real time oceanographic observations, as well as model calibration based upon temperature, current and salinity data collected during 2010 near the simulated OTEC site. The ROM program manager, Dr. Brian Powell of the University of Hawai'i, peer-reviewed Makai's implementation of the ROM output into our EFDC model. The supporting oceanographic data was collected for a Naval Facilities Engineering Command / Makai project.

    Using these models, the negatively-buoyant discharge flows were simulated by a dynamically coupled Lagrangian jet-plume entrainment model in the near-field, and by dynamic oceanic circulation and turbulence in the far-field. The result is a three-dimensional time-dependent model of the oceanic circulation, nutrient concentration due to natural variability and OTEC operation, with corresponding phytoplankton growth dynamics. This is the most sophisticated and realistic plume model yet developed for OTEC.

    Results:

    The model was run for a 100 MW OTEC Plant consisting of four separate ducts, discharging a total combined flow rate of 420 m3/s of warm water and 320 m3/s of cold water in a mixed discharge at 70 meters deep. Each duct was assumed to have a discharge port diameter of 10.5m producing a downward discharge velocity of about 2.18 m/s. The natural system, as measured in the HOTS program, has an average concentration of 10-15 mgC/m3. To calibrate the biological model, we first ran the model with no OTEC plant and varied biological parameters until the simulated data was a good match to the HOTS observations. This modeling showed that phytoplankton concentration were patchy and highly dynamic. The patchiness was a good match with the data variability observed within the HOTS data sets. We then ran the model with simulated OTEC intake and discharge flows and associated nutrients.

    Directly under the OTEC plant, the near-field plume has an average terminal depth of 172 meters, with a volumetric dilution of 13:1. The average terminal plume temperature was 19.8oC. Nitrate concentrations are 1 to 2 umol/kg above ambient. The advecting plume then further dilutes to less than 1 umol/kg above ambient within a few kilometers downstream, while remaining at depth.

    Because this terminal near-field plume is well below the 1% light limited depths (~120m), no immediate biological utilization of the nutrients occurs. The figure below shows a typical model result at 1440 on May 25th, 2010. Phytoplankton concentration at 100 meters depth is shown by the green patches that denote natural variations of between 0.010 and 0.020 milligrams carbon per cubic meter. The light blue patches delineate the slightly elevated picoplankton levels caused by the 100 MW OTEC discharge plume, raising the concentration by 0.001 or 0.0015 milligrams carbon per cubic meter. Due to varying ocean circulation, this zone of perturbation at 100 meters depth will dynamically shift location, increase in concentration, or vanish. No perturbation occurs in the upper 40 meters of the ocean.

    As the nitrate is advected and dispersed downstream, a fraction of the deep ocean nutrients (< 0.5 umol/kg perturbation) mix upward where they are utilized by the ambient phytoplankton population. This occurs approximately twenty-five kilometers downstream from the plant at 110 - 70 meters depth. For pico-phytoplankton, modeling results indicate that this nutrient perturbation causes a phytoplankton perturbation of approximately 1 mgC/m3 (~10% of average ambient concentrations) that covers an area 10x5 km in size at the 70 to 90m depth. Thus, the perturbations are well within the natural variability of the system, generally corresponding to a 10 to 15% increase above the average pico-phytoplankton biomass. This perturbation exhibits a meandering horizontal plume trajectory and spatial extent, but remains similar in magnitude (generally 1-2 mgC/m3).

    The diatom perturbations become more noticeable after three weeks of the simulation period, when the nearshore diatom population trends towards a greater concentration of 1 to 3 mgC/m3 . Relative to the background concentrations, this increased response is a fraction of the ambient, with perturbations remaining within fluctuations of the existing system. The perturbations were quantified by post-processing each time-step of model simulations without OTEC plants, with identical simulations that included OTEC plumes. Without this post processing, the 10-25% perturbations were obscured by the larger dynamic variations naturally caused by ocean circulation. Convenient summaries of the data can be viewed in Table 2 and Figure 100 of this report.

    Accomplishments Compared to Goals & Objectives:

    This modeling effort has successfully attained its goals and objectives, as listed below.

    1. Process data from an oceanographic array measuring continuous ocean current profiles, temperatures and conductivity at the Makai/Lockheed Martin initial OTEC site in West Oahu. Completed.

    2. Use these data to improve the accuracy and calibrate the local output from a newly developed regional ocean model, HIROM, which is part of an integrated global program funded by NOAA and other government agencies. Completed.

    3. Use the newly calibrated HIROM boundary conditions to force Makai’s OTEC Hydrodynamic Model, developed with State of Hawaii funds (CEROS), under various OTEC design configurations and operating conditions. Completed.

    4. Implement eutrophication modeling within the OHM to define the effect of the nutrient-rich and low oxygen deep seawater on increased productivity of phytoplankton. Completed.

    Summary:

    This study has showed that the biochemical response of OTEC discharges can be modeled, quantified, and dynamically visualized for OTEC plants having different discharge configurations. We now have an extremely useful tool for use by OTEC regulators and designers.

    In all cases modeled (discharge at 70 meters depth or more), no perturbation occurs in the upper 40 meters of the ocean's surface. The picoplankton response in the 110 - 70 meter depth layer is approximately a 10-25% increase, which is well within naturally occurring variability.

    The nanoplankton response is negligible. The enhanced productivity of diatoms (microplankton) is small, but this additional "standing stock" may potentially enhance growth if the plume water subsequently advects into nearshore water.

    Another significant finding is that detecting the plume of an OTEC pilot plant, as envisioned for the "NAVFAC OTEC Pilot Plant", will require many more samples in time and space than was originally envisioned, because ocean variability is greater than anticipated.

    Finally, the model does not attempt to calculate the higher order trophic levels where fauna consume the phytoplankton, but these results could be readily extended to this purpose. The subtle phytoplankton increase of our baseline design suggests that higher-order effects will be very small.

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